Subject: [PCN] Reporting from the trailing edge

From: Tom Taylor <[email-masked]>
Date: Thu, 30 Jul 2009 08:57:04 +0200

Phil, Anna and I were discussing the whole question of what the egress node 
reports the other day. Anna made it clearer for me why she was concerned with 
the existing state of the drafts. Because SM cannot decide on the need for 
termination without the help of the ingress node, the egress node has to send 
reports back to the ingress node whenever the admission state is "block".

At the same time, when you are operating a system at design load, CL will be 
sending back threshold crossing reports very frequently, perhaps at the end of 
most measurement periods.

We concluded that it made more sense to go back to the previous idea of shipping 
reports out at the end of every measurement period.

In the PCN WG meeting we agreed that we should explore three signalling cases:

  - reports piggy-backed on resource signalling;
  - reports using asynchronous messaging over RSVP or GIST;
These two I would call "on-path" signalling.

The third possibility would be reports sent over a direct connection between the 
egress and ingress nodes (or PDP) using reliable transport such as TCP or SCTP. 
(No, Bob, we don't have to invent our own transport.) I call this alternative 
"direct signalling".

Michael has questioned piggy-backing, and I'll let that discussion go on. In the 
meantime, please consider the proposal to report data every measurement period 
as in the pre-IETF drafts.

Tom

---

From: "Georgios Karagiannis" <[email-masked]>
Date: Thu, 30 Jul 2009 08:19:57 +0000

Hi Tom

I agree with the proposal of using the three classes of signaling
requirements that edge behaviours have to support.
The next step is to identify the content that has to be signaled and
which of the requirements should be common for all edge behaviours,
i.e., mandatory, and which of them should be optional that will only be
needed by some edge behaviour drafts.

I think that we could also use the above described classification for the
signaling requirements draft.

Best regards,
Georgios

On 7/30/2009, "Tom Taylor" <[email-masked]> wrote:

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