Subject: [Sipping] RE:[Sipping]Re:[Sip] INAP and SIP INFO

From: "F.S.Salloum" <[email-masked]>
Date: Wed, 25 Sep 2002 15:04:39 +0300

I'm little confused

First
Why is NOT a good idea to send DTMF (or PSTN signalling) with SIP INFO?

Second
I someone wants for some reason which depends on the architecture, to 
send INAP
information in another non edge SIP entity which method is the prefered 
one?

As far as I have read threee ways exist

1) Using INFO encapsulation (as for midcall signalling)
2) Using specific MIME objects (RFC3204) for INAP
3) Using SCTP according to SIGTRAN (If SIP was over SCTP then things get 
easier Am i right?)

Thanks
F.S.Salloum

_______________________________________________
Sipping mailing list  https://www1.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use [email-masked] for questions on current sip
Use [email-masked] for new developments of core SIP

---

From: Jonathan Rosenberg <[email-masked]>
Date: Mon, 30 Sep 2002 01:32:42 -0400

> Why is NOT a good idea to send DTMF (or PSTN signalling) with SIP INFO?

Because SIP INFOs are sent unsolicited. The result is that each keypress 
genreates signaling traffic when no element might actually care. The 
only unsolicited DTMF that should be sent is to the UA on the other 
side. In that case, rfc2833 is far, far better than INFO. It will allow 
synchornization with the media stream, it doesn' touch proxies or any 
intermediaries, so it generates no signaling load, etc.

> information in another non edge SIP entity which method is the prefered 

None.

It is not appropriate to encapsuate INAP in SIP.

Just like its not appropriate to encapsulate DNS or RIP or OSPF or a 
host of other unrelated protocols in SIP.

-Jonathan R.
-- 
Jonathan D. Rosenberg, Ph.D.                72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (973) 952-5050
http://www.jdrosen.net                      PHONE: (973) 952-5000
http://www.dynamicsoft.com