Subject: [dispatch] Draft new version: draft-holmberg-dispatch-iotl-01

From: Christer Holmberg <[email-masked]>
Date: Fri, 13 Jun 2014 09:33:09 +0000

Hi,

Based on the comments from Paul and Dale, we have submitted a new version of the draft-holmberg-dispatch-iotl draft.

It still aims at specifying a generic mechanism. But, as discussed earlier, we may change it into a 3GPP specific one.

We added some text on things that needed to be clarified (see change log), and we also added some example flows.

Regards,

Christer

---

From: Paul Kyzivat <[email-masked]>
Date: Fri, 13 Jun 2014 12:20:31 -0400

On 6/13/14 5:33 AM, Christer Holmberg wrote:
> Hi,
>
> Based on the comments from Paul and Dale, we have submitted a new
> version of the draft-holmberg-dispatch-iotl draft.
>
> It still aims at specifying a generic mechanism. But, as discussed
> earlier, we may change it into a 3GPP specific one.
>
> We added some text on things that needed to be clarified (see change
> log), and we also added some example flows.

Intro:

    A traffic leg might be
    associated with multiple SIP dialogs, e.g. in case a B2BUA which
    modifies the SIP dialog identifier is located within the traffic leg.

This raises questions in my mind about the architectural model you have 
in mind. I think of a "leg" as a segment of the path that an individual 
session traverses. Multiple sessions may follow similar paths, and thus 
may have legs that traverse the same set of nodes, but are those the 
same "leg"?

It may not make any material difference, but I find it confusing.

	Thanks,
	Paul

---

From: Christer Holmberg <[email-masked]>
Date: Sat, 14 Jun 2014 09:12:54 +0000

Hi,

> may have legs that traverse the same set of nodes, but are those the

They may be, but they don't have to be. A traffic leg is not a "static thing", which automatically applies to all sessions.

Regards,

Christer

---

From: [email-masked] (Dale R. Worley)
Date: Mon, 16 Jun 2014 10:24:56 -0400

> From: Paul Kyzivat <[email-masked]>

> may have legs that traverse the same set of nodes, but are those the 

The problem is that we lack terminology.  A B2BUA can do anything, but
almost all the time, what it does in interconnect pairs of dialogs,
coupling their lifetines and arranging for the media arriving on one
to depart on the other and vice-versa (though sometimes with some sort
of transformation).  So there is often a sequence of dialogs that are
connected end-to-end by B2BUAs.

We don't have a word for that sequence of dialogs.

What this draft wants to say is that the sequence of dialogs can be
cut into segments, which are called "legs", and certain specific
processing (signaling or media) is expected to be done at the junction
points between the legs, based on the categories that the legs belong
to.

Dale

---

From: Christer Holmberg <[email-masked]>
Date: Mon, 16 Jun 2014 18:48:08 +0000

Hi,

> We don't have a word for that sequence of dialogs.

Well, the "session", as identified by the INSIPID session-id, can identity a sequence of dialog. 

> points between the legs, based on the categories that the legs belong

Correct.

But, it is important to remember that a traffic leg can orginate/terminate in the middle of a dialog or INSIPID session, which means that different parts of the same dialog/INSIPID session can be associated with different traffic legs.

Regards,

Christer