SIP/PSTN interworking draft

["Adam B. Roach" <[e-mail]>]

My interpretation of the feedback I had at last week's MMUSIC meeting 
on draft-roach-mmusic-sip-pstn-require-header-00.txt is as follows:

1. In-band DTMF transmission should be removed from the draft.

2. Call-control services should be removed from the draft.

3. Out-of-band DTMF transit is controversial.

My purpose in this message is to check if there are any counter-arguments
to the first two points which anyone would like to present, and to
begin a dialogue on the third point. 

To summarize what I beleive the main arguements for and against inclusion
of OOB DTMF:

- Christian Huitema made the point that an interworking draft should
  limit itself to those features absolutely necessary for signalling
  interworking. Since DTMF isn't a necessary part of call setup and
  teardown, it doesn't belong in this draft.

- Steve Donovan contends that, without having a requirement to send
  DTMF information in a format understood by SIP nodes, the most
  basic services (such as calling card services) will be impossible
  to implement. PSTN interworking is of limited value if you can't
  authenticate users.

I'm on the fence, myself. Both seem like valid arguments. I'd appreciate
it if anyone who has a stake in this arena would weigh in on one side
or the other. Thanks.

-- 
Adam Roach, Ericsson Inc. |  Ph: [phone] | 1010 E. Arapaho, MS L-04
[e-mail]   | Fax: [phone] | Richardson, TX 75081 USA