[Nsi-wg] Notes from call 6-24

[John Vollbrecht]

Some notes on call below.  We will have a "optional" next week and a  
regular call in two weeks.

At the end of the meeting, after a number of people had already had to  
leave, there was some discussion of what is planned for the next  
meeting at OGF in Oct.  The feeling among those present was that it  
would be good to have a first pass at an architecture document.  This  
will be a topic for discussion in two weeks, and also for initial  
discussion next week.  Some questions are the form of the document,  
the selection of topics and their current state, and what areas to  
focus on over the next couple months.

Tentative agendas --

next week - Radek's pathfinding charts- combining with Guy's messaging  
and John's Path-handling diagram
		- initial discussion of document for next OGF

two weeks - discuss document  and plans for how to create it
		-  other discussion to be determined

Notes from today

1.
Radek described his diagrams showing how path computation could be  
done in different ways.  There was a lot of very good discussion to  
clarify.

The intent of the diagrams is to show how initial paths are created.   
These are then used to request resources.

  Some questions
  - why does a network need to know internal paths of other networks?   
I think the answer was that it doesn't "have" to know, but it is  
allowed for this to be shared.
  - is this path computation part of request of separate?  I believe  
that the intent is that it is separate, although I am still a little  
confused by how this works in some diagrams.
  - how does the ability to get "next hop" and "detailed path" play  
with topology sharing and path computation.  Lots of discussion.  I  
think this still needs to be worked out.

Radek proposed that he modify the diagrams based on discussion to make  
a distinction between finding local data plane paths and general  
control plane paths.  There was a question about how global data plane  
paths are found that he will consider.  Radek had to leave after this  
discussion.


2.
We had a lot of discussion about how topology is shared, and what must  
be shared for something to work.
- Some discussion about how one finds out if a location is available.   
We discussed that the edgepoints would be described as URIs and that  
the URI would include information about the network/domain to which  
the edgepoint belongs.  In addition a lookup service has been proposed  
that will allow a dns-like name to be mapped to its URI.  This name  
might be used in the request and then NSA would use the lookup service  
to convert it to URI.
- talked more about distinction between dataplane paths and control  
plane paths.  They do not need to map to each other, and when finding  
a global route one may find a set of NSAs that can provide an  
interconnected dataplane path.  The NSAs would then figure out the  
details of the route.
- talked briefly about the distinction between route and topology.  We  
referenced Radek's abstracted topology as example of topology and  
route being a sequence of edge points and hints about how the  
edgepoints are interconnected.  Guy will try to fill out this  
distinction as part of the messaging he is working on.

3.
There was some discussion about topology sharing and what is required  
and what is optional.  Seems to be agreed that one must share  
edgepoints it wants others to know about.  edgepoints that connect  
other networks are needed in topology, edgepoints that connect to end- 
devices are needed for reachability.  It is not required that a NSA  
share everything with everybody.

4.
At the tail end of the call we talked about the use cases I sent  
out.   One question was whether these were intended to be controlled  
by NSA.  The answer was that they are meant to be input to NML group  
in discussing adaptations, and don't have to be controlled.  They do  
raise some interesting questions (as Jerry points out in his email  
earlier) that we may discuss later.

There was some agreement and no disagreement that I heard for sending  
these to NML group for their discussion.  I will send these.

---

Please correct or comment on these.  I am not sure I caught all the  
discussion.

John