Tue, Nov 19, 2002 55 SPIRITS WG 1 vkg

IETF IPTEL WG55th IETF, Atlanta, GA

Trunk Group Open Issues<draft-ietf-iptel-trunk-group-00>Vijay Gurbani, Cullen Jennings, and Jon Peterson

Presented by: Vijay Gurbani

Tue, Nov 19, 2002 55 SPIRITS WG 2 vkg

Issues

• Issue 1: “sip” URI or “tel” URI?– Defining them as extensions to the “tel” URI

appears reasonable (since trunks are tied to the PSTN, anyway).

– Easy to derive a SIP URI from the tel URI.

Tue, Nov 19, 2002 55 SPIRITS WG 3 vkg

Issues

• Issue 2: Global or local namespace?– Most trunk groups will be locally scoped;

however, for the sake of flexibility, a naming convention has been proposed in the I-D which is flexible enough to accommodate both.

– ABNF has been proposed in the I-D for this purpose, resulting in a URI which may look like:

• tel:+14085551212;tgrp=local=tg55/3

Tue, Nov 19, 2002 55 SPIRITS WG 4 vkg

Issues

• Issue 3: Originating and destination trunk groups should be able to appear separately and concurrently in the SIP message.– Originating trunk group: Contact header– Destination trunk group: R-URI

• Other options:– Originating trunk group: From header (abstract

identifier that persists even after the session is completed – probably not a good choice).

– Destination trunk group: To header (same reservation as above, plus, proxies make routing decisions based on R-URIs).

Tue, Nov 19, 2002 55 SPIRITS WG 5 vkg

Issues

• Issue 4: SIP intermediaries should be able to add the destination trunk group to SIP requests as a route is selected for the session.– Argues more in favor of using R-URI.