Subject: Re: [SIP] SIP and T.38 fax calls - Internet Draft

From: [email-masked]
Date: Tue, 31 Oct 2000 09:13:39 +0530

Jean,
in your call flows, why does the proxy change CSeq numbers ? This does not
seem warranted. Infact,
this would throw the endpoints into total confusion if a message  happened
to reach each other directly.
(I dont even see the Proxy adding a Record Route) (see 4.3 for an example )

Any reason why the proxy must re-write CSeq ? I dont see any in the first
read.

Regds
Arjun

--
Arjun Roychowdhury @ Hughes Software Systems

Jean-Francois Mule wrote:
>
> A new Internet-Draft has been submitted, dealing with real time fax calls
> and SIP: call flows and BCP.
>
> Comments and suggestions are very much appreciated.
> Regards,
> Jean-Francois Mule
>
> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]]
> Sent: Tuesday, October 17, 2000 3:47 AM
> Subject: I-D ACTION:draft-mule-sip-t38callflows-00.txt
>
> A New Internet-Draft is available from the on-line Internet-Drafts
> directories.
>
>         Title           : SIP T.38 Call Flow Examples And Best Current
> Practice
>         Author(s)       : J. Mule
>         Filename        : draft-mule-sip-t38callflows-00.txt
>         Pages           : 19
>         Date            : 16-Oct-00
>
> This document gives examples of SIP call flows for T.38 Internet fax
> communications (SIP, the Session Initiation Protocol is defined in
> RFC2543 [2] and T.38 is an ITU-T Recommendation [3]).  Elements in
> these call flows include SIP User Agents, SIP Proxy Servers, and
> Gateways to the PSTN (Public Switch Telephone Network).
> This document introduces best current practices for T.38 fax calls:
> a call starts with audio capabilities, and, upon fax tone detection,
> T.38 fax capabilities are negotiated.  The T.38 fax call scenarios
> include the detection of T.38 fax transmission by the receiving
> side, or the emitting side, or both (in the latter case, a 'glare'
> effect may appear).  The current version of this document only
> covers the case when the fax tone is detected by the receiving side
> (other cases were left for discussion and may be included in the
> future).  Call flow diagrams and message details are shown.  A list
> of IANA defined SDP attribute names for T.38 is summarized in
> section 5.
>
> A URL for this Internet-Draft is:
> http://www.ietf.org/internet-drafts/draft-mule-sip-t38callflows-00.txt
>
> Internet-Drafts are also available by anonymous FTP. Login with the
> username
> "anonymous" and a password of your e-mail address. After logging in,
> type "cd internet-drafts" and then
>         "get draft-mule-sip-t38callflows-00.txt".
>
> A list of Internet-Drafts directories can be found in
> http://www.ietf.org/shadow.html
> or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
>
<snip>

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