Hello All,
The minutes from yesterday’s call are available here:
http://forge.gridforum.org/sf/go/doc15958?nav=1
I have attached the latest version of the architecture
deliverable. This incorporates contributions and comments by Tomohiro Kudoh, Joan
Garcia, John Vollbrecht as well as some contributions by myself.
To bring some clarity to the complex discussions on advanced
reservation, I have created the following table to try and summarize the
questions that I think were raised in yesterday’s discussion. 2 options as are
proposed for each question. The solutions described in the existing architecture
deliverable is also included.
Guy
Question |
Option 1 |
Option 2 |
Existing v1.0 solution as proposed by TK |
Comments |
1 or 2 phase commit? |
1PC |
2PC |
1PC |
2PC is more deterministic for multiple network situation |
Is reservation guard-band required in 1PC? |
Yes |
No |
Yes |
For timer initiated provisioning with 1PC, the guard-band
is required to prevent partial provisioning of a connection. |
Is reservation guard-band required in 2PC? |
Yes |
No |
NA |
In practice to improve reliability of service, 2 should be
aware of the worst-case reservation times. |
Who adds Reservation guard-band? |
Added by Requester NSA |
Added by Provider NSA |
? |
This decision affects
how the StartTime field in message is interpreted. Also GB definition
will change based on this usage. (see below) |
Is reservation guard-band (GB) implemented per-network,
or for federation of networks? |
GB = worst case reservation time for local network |
GB = worst case reservation time for all participating
networks |
? |
If the GB is added by the Requester, then the GB should
refer to the worst-case time for the federation of participating networks. |
Provider validation of guard-band? |
Validated |
Not validated |
Validated |
|
Provisioning advance time |
None |
Advance time added by Provider NSA |
None |
The advance time should be set to equal the worst case
provisioning time. This is needed if the In-service time is to match
the user requested time. |
Synchronization |
NTP |
GPS/radio |
? |
NTP should be ok |
Separate command for immediate reservation? |
Yes |
No |
No |
How is immediate reservation distinguished from
advanced? This can probably be done by using ‘ASAP’ in the startTime
field. |
Allow ASAP as start-time? |
Yes |
No |
No |
|
How is provisioning initiated with ASAP startTime? |
Signalled from Requester NSA |
Initiated by timer on Provider NSA |
NA |
To get a fast result with ASAP then timer initiated
provisioning could be used. (is this much faster than signalled?) |
How should provisioning be initiated for advanced
reservations? |
Signalled from Requester NSA |
Initiated by timer on Provider NSA |
Both options supported |
In the case of 1PC and not guard-time, the outcome when
initiated by timer on Provider may not be very deterministic. |
Does each Connection request need a field to indicate
how to expect provisioning to be initiated? |
Provisioning type field |
No provisioning type field |
? |
How does Provider know whether to wait for signal from
Requester? |
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Guy Roberts, Ph.D
Network Engineering &
Planning
DANTE - www.dante.net
Tel: +44 (0)1223 371 316
City House, 126-130
Hills Road
Cambridge, CB2 1PQ,
UK
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