The minutes for yesterday's conference call are available here: http://forge.gridforum.org/sf/go/doc15952?nav=1 Guy ------------------------------------------------------------------------------------------------------------------ Guy Roberts, Ph.D Network Engineering & Planning DANTE - www.dante.net<http://www.dante.net/> Tel: +44 (0)1223 371 316 City House, 126-130 Hills Road Cambridge, CB2 1PQ, UK ------------------------------------------------------------------------------------------------------------------
Hi all, To keep the v1.0 architecture simple, I propose to not to use the immediate reservation in v1.0. Instead, I propose to define guard time, and use it as follows: - The "guard time" is: possible maximum time required to process a request and make resources ready for provisioning. - Each provider NSA must define its guard time and provide it to requester NSAs. - A requester NSA should not request a reservation which start time is smaller (earlier) than (current time + guard time). Time required for message delivery should be taken into account too. - If a provider NSA receives a reservation request which start time is before (current time + guard time), it simply denies the request. If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery). In this way, immediate provisioning can be requested by an advance reservation request. Tomohiro On Thu, 1 Apr 2010 14:54:15 +0100 Guy Roberts <Guy.Roberts@dante.net> wrote:
The minutes for yesterday's conference call are available here:
http://forge.gridforum.org/sf/go/doc15952?nav=1
Guy ------------------------------------------------------------------------------------------------------------------ Guy Roberts, Ph.D
Network Engineering & Planning DANTE - www.dante.net<http://www.dante.net/> Tel: +44 (0)1223 371 316 City House, 126-130 Hills Road Cambridge, CB2 1PQ, UK ------------------------------------------------------------------------------------------------------------------
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time. Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that? Jeroen.
Hi Jeroen, There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed. If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned. The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter. Regards, Tomohiro On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime. I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved. Guy -----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes) Hi Jeroen, There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed. If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned. The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter. Regards, Tomohiro On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits. I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen. It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)]. A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it. There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ---------------------------------- I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation John On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
John, My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work): StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification. Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm) Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm) Guy -----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes) I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits. I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen. It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)]. A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it. There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ---------------------------------- I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation John On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
To sum this up, this describes a situation where there is no prior reservation and provisioning is started immediately because the startTime is meant as a "now"? Jeroen. On 09/04/2010 18:56, Guy Roberts wrote:
John,
My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work):
StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification.
Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm)
Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm)
Guy
-----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
Jeroen, Yes, that is correct. But the mechanism will be the same for advance reservations, just a later start time. Guy -----Original Message----- From: Jeroen van der Ham [mailto:vdham@uva.nl] Sent: 12 April 2010 08:19 To: Guy Roberts Cc: John Vollbrecht; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes) To sum this up, this describes a situation where there is no prior reservation and provisioning is started immediately because the startTime is meant as a "now"? Jeroen. On 09/04/2010 18:56, Guy Roberts wrote:
John,
My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work):
StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification.
Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm)
Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm)
Guy
-----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
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Hi, I think guard time is a shaky concept, as who can tell how long it should be - it can/will depend on the number of domains the circuit contains, the speed of each reservation/provisioning system as well as the load on the system, and will be variable over time (hoping for faster reservation/provisioning systems in the future). But: if in step 5, the "wait for start time" means t_start <= t_current, then the provider will immediately pass on to provisioning. What needs to be done however is to have the duration of the reservation reflect the time difference between desired start time and the effective one. I am sure I am missing something..? Cheers, Artur On 04/12/2010 11:12 AM, Guy Roberts wrote:
Jeroen,
Yes, that is correct. But the mechanism will be the same for advance reservations, just a later start time.
Guy
-----Original Message----- From: Jeroen van der Ham [mailto:vdham@uva.nl] Sent: 12 April 2010 08:19 To: Guy Roberts Cc: John Vollbrecht; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
To sum this up, this describes a situation where there is no prior reservation and provisioning is started immediately because the startTime is meant as a "now"?
Jeroen.
On 09/04/2010 18:56, Guy Roberts wrote:
John,
My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work):
StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification.
Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm)
Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm)
Guy
-----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
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-- Dr Artur Barczyk California Institute of Technology c/o CERN, 1211 Geneve 23, Switzerland Tel: +41 22 7675801
Artur,
I think guard time is a shaky concept
Agreed, it is not an elegant engineering solution in any way, so I would like to find a way to avoid it if we can. Hence the survey proposal that I have just sent out in my last email.
"wait for start time"
This is intended to mean that once the reservation has been accepted, the realtime-clock in the provider NSA should wait until it reaches the value held in the 'start time' field of the reservation request sent by the requester NSA. Guy -----Original Message----- From: Artur Barczyk [mailto:Artur.Barczyk@cern.ch] Sent: 12 April 2010 17:28 To: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes) Hi, I think guard time is a shaky concept, as who can tell how long it should be - it can/will depend on the number of domains the circuit contains, the speed of each reservation/provisioning system as well as the load on the system, and will be variable over time (hoping for faster reservation/provisioning systems in the future). But: if in step 5, the "wait for start time" means t_start <= t_current, then the provider will immediately pass on to provisioning. What needs to be done however is to have the duration of the reservation reflect the time difference between desired start time and the effective one. I am sure I am missing something..? Cheers, Artur On 04/12/2010 11:12 AM, Guy Roberts wrote:
Jeroen,
Yes, that is correct. But the mechanism will be the same for advance reservations, just a later start time.
Guy
-----Original Message----- From: Jeroen van der Ham [mailto:vdham@uva.nl] Sent: 12 April 2010 08:19 To: Guy Roberts Cc: John Vollbrecht; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
To sum this up, this describes a situation where there is no prior reservation and provisioning is started immediately because the startTime is meant as a "now"?
Jeroen.
On 09/04/2010 18:56, Guy Roberts wrote:
John,
My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work):
StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification.
Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm)
Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm)
Guy
-----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
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-- Dr Artur Barczyk California Institute of Technology c/o CERN, 1211 Geneve 23, Switzerland Tel: +41 22 7675801 _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
Hi Guy, On 04/12/2010 06:34 PM, Guy Roberts wrote:
Artur,
I think guard time is a shaky concept
Agreed, it is not an elegant engineering solution in any way, so I would like to find a way to avoid it if we can. Hence the survey proposal that I have just sent out in my last email.
"wait for start time"
This is intended to mean that once the reservation has been accepted, the realtime-clock in the provider NSA should wait until it reaches the value held in the 'start time' field of the reservation request sent by the requester NSA.
That part of the problem I believe I understood :-) What I meant is that if that time has passed by the time the provider NSA gets notified of the reservation acceptance along the path, it should proceed directly to provisioning. You have to do this anyway, to protect against the guard time being set too short. In which case you can just as well set the guard time to 0. That's just common sense, IMO, what it means when I would ask for immediate circuit provisioning. "Please give it to me as soon as you're able to, I'm waiting." The thing not to forget is that someone can ask for a circuit not only "now", but "a minute from now", which would lead to the same problem if the time to process the reservation is longer than a minute (as it most probably will be in the next future). So the "now" string as in your option 2) would only work for a singular subset of the problem. Cheers, Artur
Guy
-----Original Message----- From: Artur Barczyk [mailto:Artur.Barczyk@cern.ch] Sent: 12 April 2010 17:28 To: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi,
I think guard time is a shaky concept, as who can tell how long it should be - it can/will depend on the number of domains the circuit contains, the speed of each reservation/provisioning system as well as the load on the system, and will be variable over time (hoping for faster reservation/provisioning systems in the future).
But: if in step 5, the "wait for start time" means t_start <= t_current, then the provider will immediately pass on to provisioning. What needs to be done however is to have the duration of the reservation reflect the time difference between desired start time and the effective one.
I am sure I am missing something..?
Cheers, Artur
On 04/12/2010 11:12 AM, Guy Roberts wrote:
Jeroen,
Yes, that is correct. But the mechanism will be the same for advance reservations, just a later start time.
Guy
-----Original Message----- From: Jeroen van der Ham [mailto:vdham@uva.nl] Sent: 12 April 2010 08:19 To: Guy Roberts Cc: John Vollbrecht; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
To sum this up, this describes a situation where there is no prior reservation and provisioning is started immediately because the startTime is meant as a "now"?
Jeroen.
On 09/04/2010 18:56, Guy Roberts wrote:
John,
My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work):
StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification.
Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm)
Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm)
Guy
-----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
_______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
-- Dr Artur Barczyk California Institute of Technology c/o CERN, 1211 Geneve 23, Switzerland Tel: +41 22 7675801
Hi All, I feel there is a lot of confusion, so let me try to explain my case/understanding. 1. Guard-time: This concept was proposed for Advanced Scheduling only. This can be a default value and it does not have to be an "exact" measurement of provisioning times. It only handles path computation and reservation times across domains. What does it mean to a user? A user CANNOT ask for a advanced reservation connection with Tstart < Tnow + Guard-time. If a user asks with a Tstart lower that Tnow + Guard-time, the scheduled request is rejected outright. With an ADvanced Scheduling function, provisioning initiation can happen from both the user or the provider. 2. On-Demand Service: In my opinion, Guard-time does not prevent an On-Demand service as specified by Jerry. They co-exist. An on-demand service, with Tstart = ASAP can be implemented very easily. The service starts when the "provisioning complete" message is received by the user. If the user does not receive that message, it continues to wait. Does this make more sense? I will answer specifics below. Inder On Apr 12, 2010, at 1:21 PM, Artur Barczyk wrote:
Hi Guy,
On 04/12/2010 06:34 PM, Guy Roberts wrote:
Artur,
I think guard time is a shaky concept
Agreed, it is not an elegant engineering solution in any way, so I would like to find a way to avoid it if we can. Hence the survey proposal that I have just sent out in my last email.
"wait for start time"
This is intended to mean that once the reservation has been accepted, the realtime-clock in the provider NSA should wait until it reaches the value held in the 'start time' field of the reservation request sent by the requester NSA.
That part of the problem I believe I understood :-) What I meant is that if that time has passed by the time the provider NSA gets notified of the reservation acceptance along the path, it should proceed directly to provisioning.
In advanced reservation, the open question is what should a domain do if Tstart comes, and it has not got a reservation complete or provision message? Should it delete the connection or provision its own set of resources? Chin and I include this case in the error recovery document to be published soon.
You have to do this anyway, to protect against the guard time being set too short. In which case you can just as well set the guard time to 0.
That's just common sense, IMO, what it means when I would ask for immediate circuit provisioning. "Please give it to me as soon as you're able to, I'm waiting."
The thing not to forget is that someone can ask for a circuit not only "now",
I think the "now" case is actually, "as soon as possible" - which is the on-demand case. Then it just waits for the right message from the Provider Agent before it knows the connection is available to be used.
but "a minute from now", which would lead to the same problem if the time to
A minute from now actually becomes a "scheduled connection" and there is where the problem really starts. I feel we should support both Advanced Reservation with guard-time and On-demand connection service. Inder
process the reservation is longer than a minute (as it most probably will be in the next future). So the "now" string as in your option 2) would only work for a singular subset of the problem.
Cheers, Artur
Guy
-----Original Message----- From: Artur Barczyk [mailto:Artur.Barczyk@cern.ch] Sent: 12 April 2010 17:28 To: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi,
I think guard time is a shaky concept, as who can tell how long it should be - it can/will depend on the number of domains the circuit contains, the speed of each reservation/provisioning system as well as the load on the system, and will be variable over time (hoping for faster reservation/provisioning systems in the future).
But: if in step 5, the "wait for start time" means t_start <= t_current, then the provider will immediately pass on to provisioning. What needs to be done however is to have the duration of the reservation reflect the time difference between desired start time and the effective one.
I am sure I am missing something..?
Cheers, Artur
On 04/12/2010 11:12 AM, Guy Roberts wrote:
Jeroen,
Yes, that is correct. But the mechanism will be the same for advance reservations, just a later start time.
Guy
-----Original Message----- From: Jeroen van der Ham [mailto:vdham@uva.nl] Sent: 12 April 2010 08:19 To: Guy Roberts Cc: John Vollbrecht; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
To sum this up, this describes a situation where there is no prior reservation and provisioning is started immediately because the startTime is meant as a "now"?
Jeroen.
On 09/04/2010 18:56, Guy Roberts wrote:
John,
My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work):
StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification.
Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm)
Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm)
Guy
-----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote: > If a requester wants resources to be provisioned as soon as > possible, it > can set the start time parameter in a advance request to: > (current time + guard time + a certain time required for message > delivery). > > In this way, immediate provisioning can be requested by an advance > reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
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-- Dr Artur Barczyk California Institute of Technology c/o CERN, 1211 Geneve 23, Switzerland Tel: +41 22 7675801 _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
--- Inder Monga http://100gbs.lbl.gov imonga@es.net http://www.es.net (510) 499 8065 (c) (510) 486 6531 (o)
Hi Inder, I see, thanks for this clarification. I still think we are introducing an artificial decision step here, which will just be confusing to the end-user (and make the whole system more complex), and I still wonder about the necessity of it. Please see in-line: On 04/12/2010 11:15 PM, Inder Monga wrote:
Hi All,
I feel there is a lot of confusion, so let me try to explain my case/understanding.
1. Guard-time: This concept was proposed for Advanced Scheduling only. This can be a default value and it does not have to be an "exact" measurement of provisioning times. It only handles path computation and reservation times across domains.
What does it mean to a user? A user CANNOT ask for a advanced reservation connection with Tstart < Tnow + Guard-time. If a user asks with a Tstart lower that Tnow + Guard-time, the scheduled request is rejected outright.
Imagine I try to make a connection "NOW", and it gets refused after N minutes due to lack of resources. Then I try "2 minutes from now", and it gets rejected straight off. We shouldn't aim at having expert users who would understand this. I think the system should behave in the same (and deterministic) way, independent of what the user states in reservation time. (Btw - that the reservation and provisioning time might vary does not make it less deterministic.)
With an ADvanced Scheduling function, provisioning initiation can happen from both the user or the provider.
2. On-Demand Service: In my opinion, Guard-time does not prevent an On-Demand service as specified by Jerry. They co-exist. An on-demand service, with Tstart = ASAP can be implemented very easily. The service starts when the "provisioning complete" message is received by the user. If the user does not receive that message, it continues to wait.
Exactly what I was aiming at - but the same logic can apply to any time between "NOW" and the guard time, or doesn't it? All you need to do, if the start time is reached before the reservation is complete, to wait for the latter.
Does this make more sense?
I will answer specifics below.
[...]
What I meant is that if that time has passed by the time the provider NSA gets notified of the reservation acceptance along the path, it should proceed directly to provisioning.
In advanced reservation, the open question is what should a domain do if Tstart comes, and it has not got a reservation complete or provision message? Should it delete the connection or provision its own set of resources? Chin and I include this case in the error recovery document to be published soon.
No, no - simply wait for the reservation to complete. Only then will you know if it succeeded in the first place. IMO, the provisioning and reservation systems cannot be completely decoupled. The provisioning stage should actually never be reached until a reservation is complete. It is dependent on the outcome of the path computation as well as resource reservation. Never go to provisioning before you know you can have the resources.
You have to do this anyway, to protect against the guard time being set too short. In which case you can just as well set the guard time to 0.
That's just common sense, IMO, what it means when I would ask for immediate circuit provisioning. "Please give it to me as soon as you're able to, I'm waiting."
The thing not to forget is that someone can ask for a circuit not only "now",
I think the "now" case is actually, "as soon as possible" - which is the on-demand case. Then it just waits for the right message from the Provider Agent before it knows the connection is available to be used.
Yes, absolutely agree - that's a discussion terminology, which I'd be happy to change :-) However, we need to be precise on what we mean. An "ASAP" reservation, from a user's point of view, could mean really "any time possible, starting from now", i.e. also in 2 hours, if the resources will only then become available. I am not sure BoD does mean that. Will in such a case a BoD reservation be converted into a scheduled one?
but "a minute from now", which would lead to the same problem if the time to
A minute from now actually becomes a "scheduled connection" and there is where the problem really starts.
I am sorry I have missed large parts of this discussion, being kept off with other workload. Sorry if I am coming back to things which might be obvious to you by now. But I do not really understand where the problem really is. You mention the provisioning system to have to decide what to do if the reservation step is not complete - but I think the right design decision would be that the system should never actually be in such a state. (Sorry, I am falling into thinking in terms of state machines here, but well, that's what I start to believe would be good here.) Is there other reasons? Cheers, Artur
I feel we should support both Advanced Reservation with guard-time and On-demand connection service.
Inder
process the reservation is longer than a minute (as it most probably will be in the next future). So the "now" string as in your option 2) would only work for a singular subset of the problem.
Cheers, Artur
Guy
-----Original Message----- From: Artur Barczyk [mailto:Artur.Barczyk@cern.ch] Sent: 12 April 2010 17:28 To: nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi,
I think guard time is a shaky concept, as who can tell how long it should be - it can/will depend on the number of domains the circuit contains, the speed of each reservation/provisioning system as well as the load on the system, and will be variable over time (hoping for faster reservation/provisioning systems in the future).
But: if in step 5, the "wait for start time" means t_start <= t_current, then the provider will immediately pass on to provisioning. What needs to be done however is to have the duration of the reservation reflect the time difference between desired start time and the effective one.
I am sure I am missing something..?
Cheers, Artur
On 04/12/2010 11:12 AM, Guy Roberts wrote:
Jeroen,
Yes, that is correct. But the mechanism will be the same for advance reservations, just a later start time.
Guy
-----Original Message----- From: Jeroen van der Ham [mailto:vdham@uva.nl] Sent: 12 April 2010 08:19 To: Guy Roberts Cc: John Vollbrecht; nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
To sum this up, this describes a situation where there is no prior reservation and provisioning is started immediately because the startTime is meant as a "now"?
Jeroen.
On 09/04/2010 18:56, Guy Roberts wrote:
John,
My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work):
StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification.
Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm)
Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm)
Guy
-----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
> In this case, only some parts of inter-network connection will be > provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl <mailto:vdham@uva.nl>> wrote:
> On 07/04/2010 15:02, Tomohiro Kudoh wrote: >> If a requester wants resources to be provisioned as soon as >> possible, it >> can set the start time parameter in a advance request to: >> (current time + guard time + a certain time required for message >> delivery). >> >> In this way, immediate provisioning can be requested by an advance >> reservation request. > > The procedure above seems overly complicated and if I really am > pressed > for time, and I miscalculate the (current time + guard time + > delivery > time) by a few seconds. Denying the request means that I have to do > it > all over again, making me even more pressed for time. > > Why not keep things simple and always interpret a start time in the > past > as "now" ? (provided the end-time is in the future too) > Would there be any problems associated with that? > > Jeroen.
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-- Dr Artur Barczyk California Institute of Technology c/o CERN, 1211 Geneve 23, Switzerland Tel: +41 22 7675801 _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> http://www.ogf.org/mailman/listinfo/nsi-wg
--- Inder Monga http://100gbs.lbl.gov imonga@es.net <mailto:imonga@es.net> http://www.es.net (510) 499 8065 (c) (510) 486 6531 (o)
-- Dr Artur Barczyk California Institute of Technology c/o CERN, 1211 Geneve 23, Switzerland Tel: +41 22 7675801
Hi, I tried to catch up the discussion, hope I did not missed anything. What is hard for me to understand is why are we trying to define measurable parameters (connection activation time) basing on non-deterministic, immeasurable parameters (guard time). Even if we measured how much time it takes to reserve and activate connection in a domain, we have only statistical view on how much time it MAY (SHOULD) take. Any change to the network, NSI architecture, HW, or even SF may extend this time unexpectedly, without prior notification. This is not something we can measure (or we need to do that constantly, changing guard time value every time, which in fact does not solve everything). IMHO we can't promise something we could not prove or be sure of. I am happy to measure guard time, add safe value (e.g. res + activation takes 4 minutes, + 2 minutes safe time = 6 minutes) and say to we SHOULD deliver a connection in less than 6 minutes. If we say we MUST provide it in less than 6 minutes, we have an issue. I am rather more familiar with the option where connection is delivered as soon as possible, which means each domain performs reservation, then signalling is initialized immediately after resources are booked. Does user care if he gets it now = current time, or = current time + "gurad time or whatever"? I suppose not. If I want a circuit now, I expect to get it ASAP, which does not means it's deterministic. I am fine with knowledge I will get it around 6 minutes (statistically), but I must be immediately notified about activation. If we want to go into time details, we will get into very funny things like GPS synchronisation between users, NSA agents, networks, and domains. This is not a real-time system, not everything is deterministic, and not everything can be guaranteed. We can reconsider naming of the service, and change it from immediate to ASAP. I am not sure if we should focus on this small issue, while facing resources guarantee in advance reservation mode. Try to guarantee there anything for 100% in 2 months time period:) Even if you assume no network/HW failures. Best regards Radek ________________________________________________________________________ Radoslaw Krzywania Network Research and Development Poznan Supercomputing and radek.krzywania@man.poznan.pl Networking Center +48 61 858 20 28 http://www.man.poznan.pl ________________________________________________________________________
-----Original Message----- From: nsi-wg-bounces@ogf.org [mailto:nsi-wg-bounces@ogf.org] On Behalf Of Artur Barczyk Sent: Tuesday, April 13, 2010 10:11 AM To: Inder Monga Cc: nsi-wg@ogf.org; Guy Roberts Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Inder,
I see, thanks for this clarification.
I still think we are introducing an artificial decision step here, which will just be confusing to the end-user (and make the whole system more complex), and I still wonder about the necessity of it. Please see in-line:
On 04/12/2010 11:15 PM, Inder Monga wrote:
Hi All,
I feel there is a lot of confusion, so let me try to explain my case/understanding.
1. Guard-time: This concept was proposed for Advanced Scheduling only. This can be a default value and it does not have to be an "exact" measurement of provisioning times. It only handles path computation and reservation times across domains.
What does it mean to a user? A user CANNOT ask for a advanced reservation connection with Tstart < Tnow + Guard-time. If a user asks with a Tstart lower that Tnow + Guard-time, the scheduled request is rejected outright.
Imagine I try to make a connection "NOW", and it gets refused after N minutes due to lack of resources. Then I try "2 minutes from now", and it gets rejected straight off. We shouldn't aim at having expert users who would understand this. I think the system should behave in the same (and deterministic) way, independent of what the user states in reservation time. (Btw - that the reservation and provisioning time might vary does not make it less deterministic.)
With an ADvanced Scheduling function, provisioning initiation can happen from both the user or the provider.
2. On-Demand Service: In my opinion, Guard-time does not prevent an On-Demand service as specified by Jerry. They co-exist. An on-demand service, with Tstart = ASAP can be implemented very easily. The service starts when the "provisioning complete" message is received by the user. If the user does not receive that message, it continues to wait.
Exactly what I was aiming at - but the same logic can apply to any time between "NOW" and the guard time, or doesn't it? All you need to do, if the start time is reached before the reservation is complete, to wait for the latter.
Does this make more sense?
I will answer specifics below.
[...]
What I meant is that if that time has passed by the time the provider NSA gets notified of the reservation acceptance along the path, it should proceed directly to provisioning.
In advanced reservation, the open question is what should a domain do if Tstart comes, and it has not got a reservation complete or provision message? Should it delete the connection or provision its own set of resources? Chin and I include this case in the error recovery document to be published soon.
No, no - simply wait for the reservation to complete. Only then will you know if it succeeded in the first place.
IMO, the provisioning and reservation systems cannot be completely decoupled. The provisioning stage should actually never be reached until a reservation is complete. It is dependent on the outcome of the path computation as well as resource reservation. Never go to provisioning before you know you can have the resources.
You have to do this anyway, to protect against the guard time being set too short. In which case you can just as well set the guard time to 0.
That's just common sense, IMO, what it means when I would ask for immediate circuit provisioning. "Please give it to me as soon as you're able to, I'm waiting."
The thing not to forget is that someone can ask for a circuit not only "now",
I think the "now" case is actually, "as soon as possible" - which is the on-demand case. Then it just waits for the right message from the Provider Agent before it knows the connection is available to be used.
Yes, absolutely agree - that's a discussion terminology, which I'd be happy to change :-) However, we need to be precise on what we mean. An "ASAP" reservation, from a user's point of view, could mean really "any time possible, starting from now", i.e. also in 2 hours, if the resources will only then become available. I am not sure BoD does mean that. Will in such a case a BoD reservation be converted into a scheduled one?
but "a minute from now", which would lead to the same problem if the time to
A minute from now actually becomes a "scheduled connection" and there is where the problem really starts.
I am sorry I have missed large parts of this discussion, being kept off with other workload. Sorry if I am coming back to things which might be obvious to you by now. But I do not really understand where the problem really is. You mention the provisioning system to have to decide what to do if the reservation step is not complete - but I think the right design decision would be that the system should never actually be in such a state. (Sorry, I am falling into thinking in terms of state machines here, but well, that's what I start to believe would be good here.)
Is there other reasons?
Cheers, Artur
I feel we should support both Advanced Reservation with guard-time and On-demand connection service.
Inder
process the reservation is longer than a minute (as it most probably will be in the next future). So the "now" string as in your option 2) would only work for a singular subset of the problem.
Cheers, Artur
Guy
-----Original Message----- From: Artur Barczyk [mailto:Artur.Barczyk@cern.ch] Sent: 12 April 2010 17:28 To: nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi,
I think guard time is a shaky concept, as who can tell how long it should be - it can/will depend on the number of domains the circuit contains, the speed of each reservation/provisioning system as well as the load on the system, and will be variable over time (hoping for faster reservation/provisioning systems in the future).
But: if in step 5, the "wait for start time" means t_start <= t_current, then the provider will immediately pass on to provisioning. What needs to be done however is to have the duration of the reservation reflect the time difference between desired start time and the effective one.
I am sure I am missing something..?
Cheers, Artur
On 04/12/2010 11:12 AM, Guy Roberts wrote:
Jeroen,
Yes, that is correct. But the mechanism will be the same for advance reservations, just a later start time.
Guy
-----Original Message----- From: Jeroen van der Ham [mailto:vdham@uva.nl] Sent: 12 April 2010 08:19 To: Guy Roberts Cc: John Vollbrecht; nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
To sum this up, this describes a situation where there is no prior reservation and provisioning is started immediately because the startTime is meant as a "now"?
Jeroen.
On 09/04/2010 18:56, Guy Roberts wrote:
John,
My thinking of how it could work is as follows (though the details are really part of the protocol definition group's work):
StartTime= time when the provisioning is begun. This is the only possible meaning for StartTime since we have no way of knowing how long the provisioning will take in advance of the provisioning being performed. i.e provisioning completion time is non-deterministic. For consistency as an asynchronous system, the completion of provisioning (in-service) is pushed by the NRM to the Provider which in turn sends this to the Requestor as a notification.
Locally initiated provisioning: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider starts provisioning locally (12:05pm) 7. Provider waits for confirmation of provisioning from NRM (12:06pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:06pm)
Provisioning signalled by Requester: 1. The Requester NSA creates a request with a start time (StartTime). StartTime= NSAs current time + Requester guard time. Eg 12:00pm + 5 minutes = 12:05pm. 2. Provider validates the start time as being at least the provider guard time away from now. (note requester and provider guard times could be a little different to allow for transmission delay of request) 3. Provider begins the reservation process (12:01pm) 4. Provider completes the reservation (12:02pm) 5. Provider waits for the startTime (12:05pm) 6. Provider waits for the signal to provision (12:10pm) 7. Provider initiates provisioning of the Connection (12:10pm) 7. Provider waits for confirmation of provisioning from NRM (12:11pm) 8. Provider sends a notification to the requestor NSA to notify that the connection is in-service (12:11pm)
Guy
-----Original Message----- From: John Vollbrecht [mailto:jrv@internet2.edu] Sent: 09 April 2010 17:28 To: Guy Roberts Cc: John Vollbrecht; Tomohiro Kudoh; Jeroen van der Ham; nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
> Tomohiro, > >> In this case, only some parts of inter-network connection will be >> provisioned. > > Right, I forgot about this reason - it is a good point. Again, I > think we are not complicating things too much if we have a rule that > the Requester NSA cannot send a start time sooner than now+guardtime. > > I think we can solve the chain issue by not forcing any value for > the guard time. This can be a policy decision to suit the service > type, equipment and number of networks involved. > > Guy > > -----Original Message----- > From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] > Sent: 09 April 2010 09:04 > To: Jeroen van der Ham > Cc: nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> > Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf > call minutes) > > Hi Jeroen, > > There is a problem for inter-network connection. During the > discussions > in some calls, the problem of synchronizing networks (managed by > different NSAs) was discussed. > > If you use the "now" type request for inter-network connection > (without > complicated coordination), the actual provisioning time of networks > may > be different. Moreover, some networks may provision resources before > some other networks reply to the request, and such networks might deny > the request. In this case, only some parts of inter-network connection > will be provisioned. > > The guard time is one of the simple solutions to solve this problem. I > understand there can be multiple ways to cope with this, but all of > them > will introduce some complication to some part (note that we decided > not > to use 2PC for the v1.0). This is a design choice matter. > > Regards, > > Tomohiro > > > On Thu, 08 Apr 2010 09:27:59 +0200 > Jeroen van der Ham <vdham@uva.nl <mailto:vdham@uva.nl>> wrote: > >> On 07/04/2010 15:02, Tomohiro Kudoh wrote: >>> If a requester wants resources to be provisioned as soon as >>> possible, it >>> can set the start time parameter in a advance request to: >>> (current time + guard time + a certain time required for message >>> delivery). >>> >>> In this way, immediate provisioning can be requested by an advance >>> reservation request. >> >> The procedure above seems overly complicated and if I really am >> pressed >> for time, and I miscalculate the (current time + guard time + >> delivery >> time) by a few seconds. Denying the request means that I have to do >> it >> all over again, making me even more pressed for time. >> >> Why not keep things simple and always interpret a start time in the >> past >> as "now" ? (provided the end-time is in the future too) >> Would there be any problems associated with that? >> >> Jeroen. > > > > _______________________________________________ > nsi-wg mailing list > nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> > http://www.ogf.org/mailman/listinfo/nsi-wg > _______________________________________________ > nsi-wg mailing list > nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> > http://www.ogf.org/mailman/listinfo/nsi-wg
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-- Dr Artur Barczyk California Institute of Technology c/o CERN, 1211 Geneve 23, Switzerland Tel: +41 22 7675801 _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org <mailto:nsi-wg@ogf.org> http://www.ogf.org/mailman/listinfo/nsi-wg
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Hi John- (I'm back...:-) These are all very important points, and regarding the temporal scheduling and timing issues these concern me too. IMO, the solutions we have discussed do not sit well with folks generally speaking - I know I feel like we have created a complex monster to deal with what the user believes to be a relatvely simple request: I need a connection now, please. (Meaning: I need a connection by any means you have currently avalaible and I only want to know if you have it completed or that your can't do it at the moment.) I will contact a couple of you to catch up on the current state of the discussion before I comment more. Thanks Jerry John Vollbrecht wrote:
I am still a bit confused. Perhaps someone could do a timing diagram like the one Tomohiro did a while ago when we were discussing 2 phase commits.
I will try to explain my confusion. My understanding has been that we agreed that provisioning would never be done without prior reservation. So it would seem that the question being discussed is "what is the time being requested in a reservation". If the reservation succeeds then provisioning can happen.
It seems to me one question is how to define the start time being requested. The options seem to be that is is either 1) the time the circuit is actually provisioned and ready to use or 2) the time that provisioning of the circuit starts. In one case the previous connection may terminate sooner by the guard time and in the latter it may start later by the guard time. If it is (1) then a connection scheduled for now must have been started at [now - (start time)].
A second question is whether is is possible to request a connection that starts "now". This implies reserving a connection and initiating it as soon as it is reserved. Assume that start time is when provisioning a circuit starts (case 2 above). It seems that main issue with this is whether the time to reserve a connection is longer than the requestor is willing to wait. The time it takes depends on how many NSAs are "chained" to satisfy the request and how long each NSA takes to reserve the connection. This time is "authorization time" not guard time as I understand it.
There is another issue with defining authorization as "now" instead of a specific time. The problem is that each NSA in a chain will think authorization happens at a slightly different time. I am not sure how important this is - it doesn't seem too important to me, but perhaps I am wrong. If provisioning starts after the reservation is complete, then everything should be reserved, if at a slightly different time. ----------------------------------
I think Guy is suggesting that start time is when provisioning starts (case 2) above. That seems simplest to me. I am not sure the provisioning time is important, and if not I would think it good to include "immediate" reservation
John
On Apr 9, 2010, at 11:15 AM, Guy Roberts wrote:
Tomohiro,
In this case, only some parts of inter-network connection will be provisioned.
Right, I forgot about this reason - it is a good point. Again, I think we are not complicating things too much if we have a rule that the Requester NSA cannot send a start time sooner than now+guardtime.
I think we can solve the chain issue by not forcing any value for the guard time. This can be a policy decision to suit the service type, equipment and number of networks involved.
Guy
-----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 09 April 2010 09:04 To: Jeroen van der Ham Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes)
Hi Jeroen,
There is a problem for inter-network connection. During the discussions in some calls, the problem of synchronizing networks (managed by different NSAs) was discussed.
If you use the "now" type request for inter-network connection (without complicated coordination), the actual provisioning time of networks may be different. Moreover, some networks may provision resources before some other networks reply to the request, and such networks might deny the request. In this case, only some parts of inter-network connection will be provisioned.
The guard time is one of the simple solutions to solve this problem. I understand there can be multiple ways to cope with this, but all of them will introduce some complication to some part (note that we decided not to use 2PC for the v1.0). This is a design choice matter.
Regards,
Tomohiro
On Thu, 08 Apr 2010 09:27:59 +0200 Jeroen van der Ham <vdham@uva.nl> wrote:
On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time.
Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that?
Jeroen.
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Jeroen, This is a good point and I like the idea of dispensing with the guard time. Judging by the discussions it is causing more confusion that it is solving. Since NSI is defining the protocol only, the use of a guard time could be implemented in the NSA on a local policy basis - in this case we can ignore it as a protocol issue. Some reasons why it was proposed: 1. From my understanding of the discussion, a guard time was proposed to prevent race conditions between low and high priority traffic. This is not necessary for v 1.0 since we only support advance reservation and near-immediate reservation, where the start time can be close to now. 2. Another justification for the guard time is to improve security. A guard time would allow all of the segments to be provisioned at the same time, preventing misconnection. My feeling here is that this is futile as we cannot guarantee the time taken to perform provisioning - this can be several minutes on the Alcatel equipment and a few seconds on other equipment. So on this basis, I suggest we leave any discussion of guard bands out of the architecture document, except as a passing reference to usage based on local NSA policy. i.e the Requester NSA can set the start time to no sooner than now + guard time, this can then be validated at receipt by the Provider NSA. Guy -----Original Message----- From: Jeroen van der Ham [mailto:vdham@uva.nl] Sent: 08 April 2010 08:28 To: Tomohiro Kudoh Cc: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes) On 07/04/2010 15:02, Tomohiro Kudoh wrote:
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
The procedure above seems overly complicated and if I really am pressed for time, and I miscalculate the (current time + guard time + delivery time) by a few seconds. Denying the request means that I have to do it all over again, making me even more pressed for time. Why not keep things simple and always interpret a start time in the past as "now" ? (provided the end-time is in the future too) Would there be any problems associated with that? Jeroen. _______________________________________________ nsi-wg mailing list nsi-wg@ogf.org http://www.ogf.org/mailman/listinfo/nsi-wg
Hi all, I proposed the guard time scheme since I understood there has been a consensus of not to use 2PC or reservation confirmation in the WG. Following such constraints, the guard-time is a simple way to mimic immediate reservation. However, according to the discussion of the list and the last call, most of people do not think it is acceptable, and I think we can re-consider adoption of 2PC. So, let me propose another choice of reservation operation as attached. Tomohiro On Wed, 07 Apr 2010 22:02:08 +0900 Tomohiro Kudoh <t.kudoh@aist.go.jp> wrote:
Hi all,
To keep the v1.0 architecture simple, I propose to not to use the immediate reservation in v1.0. Instead, I propose to define guard time, and use it as follows:
- The "guard time" is: possible maximum time required to process a request and make resources ready for provisioning.
- Each provider NSA must define its guard time and provide it to requester NSAs.
- A requester NSA should not request a reservation which start time is smaller (earlier) than (current time + guard time). Time required for message delivery should be taken into account too.
- If a provider NSA receives a reservation request which start time is before (current time + guard time), it simply denies the request.
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
Tomohiro
On Thu, 1 Apr 2010 14:54:15 +0100 Guy Roberts <Guy.Roberts@dante.net> wrote:
The minutes for yesterday's conference call are available here:
http://forge.gridforum.org/sf/go/doc15952?nav=1
Guy ------------------------------------------------------------------------------------------------------------------ Guy Roberts, Ph.D
Network Engineering & Planning DANTE - www.dante.net<http://www.dante.net/> Tel: +44 (0)1223 371 316 City House, 126-130 Hills Road Cambridge, CB2 1PQ, UK ------------------------------------------------------------------------------------------------------------------
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Hi All, Having reviewed our discussions on advanced reservation, I have the following observations: 1. we agreed in Munich to go with 1PC 2. in the process of writing up 1PC in the architecture document, we discovered some of the subtleties around timing and multi-domain provisioning could result in non-deterministic behaviour. 3. this was tackled with a proposal to incorporate confirmation messages and guard-bands. 4. these modification have enhanced the 1PC behaviour to be close to the original 2PC proposal. In light of this, I am in favour of moving directly to a 2 phase commit solution for v1.0. This will future-proof the NSI protocol. In my view this is important since any enhancement from 1PC to 2PC will require backward compatibility - and this is likely to be difficult process. Can I request that you please read through Tomohiro's proposal as I would like to get agreement on this topic on this Wednesday's call. Thanks, Guy -----Original Message----- From: Tomohiro Kudoh [mailto:t.kudoh@aist.go.jp] Sent: 19 April 2010 09:19 To: nsi-wg@ogf.org Subject: Re: [Nsi-wg] Immediate/Advance reservation (Re: NSI conf call minutes) Hi all, I proposed the guard time scheme since I understood there has been a consensus of not to use 2PC or reservation confirmation in the WG. Following such constraints, the guard-time is a simple way to mimic immediate reservation. However, according to the discussion of the list and the last call, most of people do not think it is acceptable, and I think we can re-consider adoption of 2PC. So, let me propose another choice of reservation operation as attached. Tomohiro On Wed, 07 Apr 2010 22:02:08 +0900 Tomohiro Kudoh <t.kudoh@aist.go.jp> wrote:
Hi all,
To keep the v1.0 architecture simple, I propose to not to use the immediate reservation in v1.0. Instead, I propose to define guard time, and use it as follows:
- The "guard time" is: possible maximum time required to process a request and make resources ready for provisioning.
- Each provider NSA must define its guard time and provide it to requester NSAs.
- A requester NSA should not request a reservation which start time is smaller (earlier) than (current time + guard time). Time required for message delivery should be taken into account too.
- If a provider NSA receives a reservation request which start time is before (current time + guard time), it simply denies the request.
If a requester wants resources to be provisioned as soon as possible, it can set the start time parameter in a advance request to: (current time + guard time + a certain time required for message delivery).
In this way, immediate provisioning can be requested by an advance reservation request.
Tomohiro
On Thu, 1 Apr 2010 14:54:15 +0100 Guy Roberts <Guy.Roberts@dante.net> wrote:
The minutes for yesterday's conference call are available here:
http://forge.gridforum.org/sf/go/doc15952?nav=1
Guy -------------------------------------------------------------------- ---------------------------------------------- Guy Roberts, Ph.D
Network Engineering & Planning DANTE - www.dante.net<http://www.dante.net/> Tel: +44 (0)1223 371 316 City House, 126-130 Hills Road Cambridge, CB2 1PQ, UK -------------------------------------------------------------------- ----------------------------------------------
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All, Attached is the following document: Inter-Domain Controller (IDC) Protocol Specification We would like to submit this document to the NSI Working Group to consider for publication as a NSI WG Informational Document. This is being submitted on behalf of the DICE Control Plane Working Group, where the IDC Protocol (IDCP) was developed. DICE is a collaboration amongst DANTE (GEANT), Internet2, CANARIE, ESnet, USLHCnet, and others. This protocol has been implemented and is currently deployed by ESnet, Internet2, GEANT AutoBAHN, USLHCnet, and others. The objective of this submission is to provide another example of a currently deployed protocol in this area, in case it is helpful to the ongoing NSI standardization efforts. Another objective of this submission is that we would like to have the IDCP specification formally documented as an informational release in this OGF working group. There were multiple contributors to this document, which are not all listed here. However for comments, questions, suggestions and anything else relating to this document, please send to one or more of the following document editors: -Tom Lehman (USC/ISI), tlehman@east.isi.edu -Chin Guok (ESnet), chin@es.net -Andy Lake (ESnet), andy@es.net -Radoslaw Krzywania (PSNC), radek.krzywania@man.poznan.pl -Michal Balkcerkiewicz (PSNC), michalb@man.poznan.pl Thank you, Tom Lehman University of Southern California Information Sciences Institute tlehman@east.isi.edu
participants (9)
-
Artur Barczyk -
Guy Roberts -
Inder Monga -
Jeroen van der Ham -
Jerry Sobieski -
John Vollbrecht -
Radek Krzywania -
Tom Lehman -
Tomohiro Kudoh