SIP$B4XO"3F0L!$(B
(B
$B#i%3%_%e%K%1!<%7%g%s;v6HIt!&(BIP$B%=%j%e!<%7%g%s3+H/(BG$B$N?9$G$9!#(B
(B
(BRFC2833 SIP$B$G$N(BDTMF$BAw?.$K4X$9$k%$%s%W%j%a%s%H>pJs$r;29M$KAw$j$^$9!#(B
(B
(B----------------------------------
(B
(BJade,
(B
(BRFC 2833 cannot insure delivery--there are no acks and therefore no
(Bretransmissions. It does, however, rely on a certain amount of redundancy so
(Bthat if packet loss is low enough for voice, it is probably low enough for
(BDTMF.
(B
(BFor example, since it looks like you are using G.723.1, I assume your packet
(Binterval is 30ms. Therefore, at the beginning of the DTMF signal, stop
(Bgenerating audio packets and start generating DTMF packets at the same
(Binterval--every 30ms. While the signal continues, continue generating DTMF
(Bpackets every 30ms. When the signal ends, transmit the last DTMF packet
(Bthree more times (for a total of four times--some implementations get this
(Bwrong) and then switch back to generating audio packets. It works pretty
(Bwell.
(B
(BPaul
(B
(B-----Original Message-----
(BFrom: [EMAIL PROTECTED]
(B[mailto:[EMAIL PROTECTED]]On Behalf Of Jade Chen
(BYan
(BSent: Monday, February 17, 2003 9:26 PM
(BTo: [EMAIL PROTECTED]
(BCc: [EMAIL PROTECTED]
(BSubject: [Sip-implementors] Re:DTMF in SIP
(B
(B
(BDear Paul,
(B
(BThank u for your help.We inserted the DTMF into the RTP audio stream
(B(G.7231). The packets r often lost.
(B
(BMany people recommend using RFC 2833 . But I wonder how RFC 2833 can insure
(Bthe reliability transport of DTMF events.I cannot get much from the RFC
(B2833.
(B
(BRegards,
(BJade
(B
(B
(B_________________________________________________________________
(BOriginal Message:
(B
(BMessage: 1
(BFrom: "Paul Long" <[EMAIL PROTECTED]>
(BTo: "Sip-Implementors \(E-mail\)" <[EMAIL PROTECTED]>
(BSubject: RE: [Sip-implementors] DTMF in SIP
(BDate: Sat, 15 Feb 2003 18:57:54 -0600
(B
(BAdetya,
(B
(BUse RFC 2833 (http://www.ietf.org/rfc/rfc2833.txt). In your original query,
(Bby, "we use RTP to carry the DTMF, but we found that it was not reliable,"
(Bdid you mean that you inserted DTMF into the RTP audio stream as audio or
(Bthat you have implemented RFC 2833 but found some problem with it? If the
(Blatter, what was the problem?
(B
(BPaul
(B
(B_______________________________________________
(BSip-implementors mailing list
([EMAIL PROTECTED]
(Bhttp://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
(B
(B_______________________________________________
(BSip-implementors mailing list
([EMAIL PROTECTED]
(Bhttp://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
