IP Telephony WG (iptel)

MONDAY, March 19 at 0900-1130
==============================

CHAIR: Jonathan Rosenberg <jdrosen@dynamicsoft.com>

AGENDA:

 1. Agenda Bashing [Rosenberg] - 5 mins
 2. CPL Status and Update [Rosenberg] - 5 mins
 3. TRIP Open Issue [Rosenberg] - 10 mins
 4. Transit Network Selection [Walker] - 10 mins
 5. TRIP MIB Update and Issues  [Walker] - 10 mins
 6. Service Codes [Peterson] - 10 mins
 7. New Charter discussion [Rosenberg] - 30 mins

DESCRIPTION:

Before Internet telephony can become a widely deployed service, a number of
protocols must be deployed. These include signaling and capabilities
exchange, but
also include a number of "peripheral" protocols for providing related
services. 

The primary purpose of this working group is to develop two such supportive
protocols and a frameword document. They are: 

1. Call Processing Syntax. When a call is setup between two endpoints, the
signaling will generally pass through several servers (such as an H.323
gatekeeper)
which are responsible for forwarding, redirecting, or proxying the signaling
messages. For example, a user may make a call to j.doe@bigcompany.com. The
signaling
message to initiate the call will arrive at some server at bigcompany. This
server can inform the caller that the callee is busy, forward the call
initiation request to
another server closer to the user, or drop the call completely (among other
possibilities). It is very desirable to allow the callee to provide input to
this process,
guiding the server in its decision on how to act. This can enable a wide
variety of advanced personal mobility and call agent services. 

Such preferences can be expressed in a call processing syntax, which can be
authored by the user (or generated automatically by some tool), and then
uploaded to
the server. The group will develop this syntax, and specify means of
securely transporting and extending it. The result will be a single
standards track RFC. 

2. In addition, the group will write a service model document, which
describes the services that are enabled by the call processing syntax, and
discusses how the
syntax can be used. This document will result in a single RFC. 

3. Gateway Attribute Distribution Protocol. When making a call between an IP
host and a PSTN user, a telephony gateway must be used. The selection of
such
gateways can be based on many criteria, including client expressed
preferences, service provider preferences, and availability of gateways, in
addition to destination
telephone number. Since gateways outside of the hosts' administrative domain
might be used, a protocol is required to allow gateways in remote domains to
distribute their attributes (such as PSTN connectivity, supported codecs,
etc.) to entities in other domains which must make a selection of a gateway.
The protocol
must allow for scalable, bandwidth efficient, and very secure transmission
of these attributes. The group will investigate and design a protocol for
this purpose,
generate an Internet Draft, and advance it to RFC as appropriate.