Taking time off from the NSI the last couple weeks has
muddled my head.
Taking the current Automated GOLE demo service as an example,
we specify a VLAN to provision across the network and the
E-NNI Ethernet edge ports along the path. Are you saying that
we no longer do this and that an STP would reference
pre-defined VLANs? I am having problems visualizing.
Thanks,
John.
Not quite, John. The STP (<net>:<ep> tuple)
should be considered to be
a link into the local topology db. The physical specifics of
the
termination point are found there- not in the service request.
When processing the SR, the NSA will look up the network in
the topodb
and find a path to that network. At some point, a segment will
be
generated from the far network edge to the end point and set
to the
NSA. That NSA will realize the endpoints are local, and will
know then
to convert the NSI tuples to NRM nomenclature and any other
munging
about of the SR. The NSAs will need a local internal mechanism
to map
NSI names to local physical specifications for the NRM. That
might be a
look up name table, or it may be a name list in the topology
DB that has
the NSI name associated with a topology object. In any case,
the
topology object should have information relating to the
termination
point details - vlan tag, port, switch, availbale cap, etc.
The VLAN tag is NRM specific information and is not recognized
by NSI.
Unless we elect to define VLANs in the Service Definition,
they won't
either show up in the ReserveRequest. All the specific
hardware
information is found in the topology DB. The local NRM
topology DB will
say if the termination point is a tag on a port on a switch...
or is
just a port on a switch (or tag0 on a port on a switch).
The user doesn't know and should have to know the technical
specs
associated with an far STP in some remote land. The request
simply
specifies an STP - the networkname:endpointname tuple. The
request will
specify the bandwdith, orig and dest STP, and other parameters
defined
in the Service definition. The primitive does not have
guaranteed
attributes...(I saw these in the xsd... What are those?)
j
So based on the discussion here, have we answered Radek's
original request with respect to VLAN against the
ServiceTerminationPointType?
In my mind the answer is that the ServiceTerminationPointType
identifies the abstract interconnects, while specifics of the
service are held in the ServiceParametersType. The
tagged/untagged and specific VLAN id would be populated in the
"guaranteed" attribute sequence as per the service
definitions.
John.
Oops - one thing I should make clear below...
O
The *service* specifics - things like bandwidth or
MTU or other service
related specifics of a particular connection service are
defined in the
Service Definition. The ReservationRequest contains such
service
attributes, and they are qualified against the Service
Definitions of
the transit networks, but they are not specifically part of
the NSI-CS
protocol.
We have tried to separate the service specifics from the
protocol(s)
that communicate them. The NSI-CS protocol recognizes an
abstract
model of a "connection", but hardware specifics of a
particular
connection service offering or a particular service instance
are not
hard wired into the NSI-CS protocol. This will allow a great
deal of
flexibility to map multi-layer and heterogenous connection
services and
their dialects to the same generic and global protocol
framework.
Hope this helps a bit more..
J
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Comments inline...
On 3/29/11 6:18 AM, Guy Roberts wrote:
My understanding is that you are currently planning to implement AutoBAHN internally in GÉANT and an NSI interface facing other dynamic services. In this case, GÉANT will be treated by an NSI request as a leaf network, for this reason any connection request will be a single-Network request (i.e not a multi-domain request). This means that the Origin and Destination STPs will also be the service end-points.
This is correct.
So in this case you are able to look at the Access Framing type to find out if the STP reflects a tagged or untagged Ethernet port.
The STP *represents* a topological location where the service does or
could terminate. i.e. It *links* to the TopoDB. It is *not* the
topoDB. So using the STP name, the NSA indexes into the topologyDB to
find the corresponding topological object (a port, or VLAN, or...)
Specifics about the termination point is then found in the topology DB -
not in the STP name itself.
Access Framing types (and VLANs?) are described in the service definition associated with the connection request:
OrigSTP := NSISTP(OrigSTP)==True; /* STP */
DestSTP := NSISTP(DestSTP)==True; /* STP */
Bandwidth := 1..1000 Mbps, default=10 Mbps;
AccessFraming:= 802.1, /* payloads in untagged frames */
802.1q, /* payloads in tagged frames */
802.1ah,/* tagged frames are the payload */
default=802.1q; /* only tagged payloads */
Note that this would change if you were to implement NSI between AutoBAHN IDMs. Since the access framing only refers to the service access points, intermediate 'stitching points' between networks are represented by STPs which are technology agnostic labels only, so to find the technology detail it would be necessary to dig down (i.e perform some lookup of the full NML representation).
Yes, NSI endpoint names (STPs) are technology agnostic. They represent
points where the *service* can terminate (whatever the service may be.)
The "stitching" points are simply STPs in two adjacent networks that are
indicated to correlate to the same *topological location* i.e. if you
plug a fiber into a port, the end of the fiber, and the port interface
now correlate to the same topological location. Therefore they exhibit
the same topological characteristics. Likewise at the service level,
if your ethernet service connects to my ethernet service at a particular
endpoint on your service and a similar endpoint on my service, then
those two endpoints now correlate to the same topological location, and
exhibit the same characteristics, and they constitute the inter-domain
connection of our two networks, or the stitching point.
Guy
-----Original Message-----
From: nsi-wg-bounces@ogf.org [mailto:nsi-wg-bounces@ogf.org] On Behalf Of Radek Krzywania
Sent: 29 March 2011 10:26
To: nsi-wg@ogf.org
Subject: [Nsi-wg] comments to WSDL files
Hi,
Michal has get through the WSDL file, the comments are below:
- WSDL seems to be fine, and not very difficult to adopt in various software (i.e. AutoBAHN)
- In ServiceTerminationPointType, it would be useful to have information whether port is tagged or not (VLANs information is not stored also). I know that we would like to keep the messages as technology agnostic as possible, but we need to have a balance between functionality and simplicity/universality here. In case of AutoBAHN we can probably do some workarounds to evade the issue, however this is not plug-and-play ;)
Hej Radak-
The STP is just an NSI name. <network>:<localname> NSI does not
encode any physical topology information into the name. It is just a
name. I expect the NSA would use the name to index into a table of
local names to link to the local topologyDB. (Alternatively, the NSA may
simply search the local TopoDB for a topology object with this NSI name.
...but this is all an implementaion detail) The topoDB would indicate
whether that STP maps to a port or VLAN or something else. Since NSI
does not define any technology specific topology information, things
like VLANs and ports etc are only of significance to the local NRM
(AutoBahn in this case). And it becomes the responsibility of the NRM
(AutoBahn in this case) to provide a translation from the NSI local
endpoint name to any NRM specific denotion. (Also, since each NRM is
different, it would be impractical for the NSA to know each dialect of
every NRM it might encounter...)
We should re-iterate this: Since the specifics of physical resources
are managed by the NRM there is no need for the NSAs to know about or
to specify anything more specific than the network and localname of the
endpoint. It is the NRM's job to convert the global NSI address to the
local hardware specifics.
With regard to WSDLs, the WS implementation of the NSI CS primitives
does not redefine any of the NSI semantics. The NSI primitive XML
descriptions (the message formats) look the same regardless of whether
they are processed by a WS or by a lower layer protocol.
I hope this helps explain why we do not include hardware specifics in
the provisioning semantics. Why do you say hardware specific end point
information would be useful at the interdomain level.??
BR
Jerry
Best regards
Radek
________________________________________________________________________
Radoslaw Krzywania Network Research and Development
Poznan Supercomputing and
radek.krzywania@man.poznan.pl Networking Center
+48 61 850 25 26 http://www.man.poznan.pl
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