I agree with Sanjay and Attila. You can't specify annexb=yes and annexb=no
in the same SDP for the same payload type. Section 4.1.9 in RFC 3555
mentions:
annexb: indicates that Annex B, voice activity detection, is
used or preferred. Permissible values are "yes" and "no"
(without the quotes); "yes" is implied if this parameter is
omitted.
Obviously, "yes" and "no" together make no sense whatsoever; it has to be
either of the two (and if there is none, it is a 'yes' by default). A
previous thread on the group discussed the same aspect:
https://lists.cs.columbia.edu/pipermail/sip-implementors/2005-August/009994.
html
Though possible to achieve this using a dynamic payload theoretically (as
suggested by Attila), I'm not sure what practical purpose would it serve?
Regards,
Gaurav
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Attila Sipos
Sent: Thursday, November 16, 2006 2:17 PM
To: Sarkar, Uttam; Sanjay Sinha (sanjsinh); sudhagar NAGARAJAN;
[email protected]
Subject: Re: [Sip-implementors] Required SDP content for G729A, G729AB,
G729B
>> m=audio 10014 RTP/AVP 18 18 101
>> a=fmtp:18 annexb=no
>> a=fmtp:18 annexb=yes
I'm pretty sure the above is illegal.
It would be better to use a dynamic payload:
>> m=audio 10014 RTP/AVP 18 102 101
>> a=fmtp:18 annexb=no
>> a=rtpmap:102 G729/8000
>> a=fmtp:102 annexb=yes
Regards,
Attila
http://www.vegastream.com
>> -----Original Message-----
>> From: [EMAIL PROTECTED]
>> [mailto:[EMAIL PROTECTED] Behalf Of Sarkar,
>> Uttam
>> Sent: 15 November 2006 20:10
>> To: Sanjay Sinha (sanjsinh); sudhagar NAGARAJAN;
>> [email protected]
>> Subject: Re: [Sip-implementors] Required SDP content for
>> G729A, G729AB,
>> G729B
>>
>>
>> Actually we did send INVITE to UA specifying both G729A
>> and G729B. UA
>> did not reject the Call. We configure the UA's codec to
>> G729A and G729B
>> separately and they worked.
>> However, some UA may not like it.
>>
>> Here is a sample SDP that specify G729A and G729B.
>>
>> v=0
>> o=root 743184990 743184990 IN IP4 10.50.10.146
>> s=call
>> c=IN IP4 10.50.10.146
>> t=0 0
>> m=audio 10014 RTP/AVP 18 18 101
>> a=fmtp:18 annexb=no
>> a=fmtp:18 annexb=yes
>> a=rtpmap:101 telephone-event/8000
>> a=fmtp:101 0-15
>> a=ptime:20
>> a=sendrecv
>>
>>
>> I think G729B is G729A + VAD.
>>
>> Correct me if I am wrong.
>>
>> -----Original Message-----
>> From: [EMAIL PROTECTED]
>> [mailto:[EMAIL PROTECTED] On Behalf Of Sanjay
>> Sinha (sanjsinh)
>> Sent: Wednesday, November 15, 2006 2:58 PM
>> To: sudhagar NAGARAJAN; [email protected]
>> Subject: Re: [Sip-implementors] Required SDP content for
>> G729A, G729AB,
>> G729B
>>
>> I do not think it is possible to indicate support for G729A
>> & G729B in
>> same offer. G729B and G729AB are fully interoperable.
>>
>> >-----Original Message-----
>> >From: [EMAIL PROTECTED]
>> >[mailto:[EMAIL PROTECTED] On Behalf Of
>> >sudhagar NAGARAJAN
>> >Sent: Wednesday, November 15, 2006 4:01 AM
>> >To: [email protected]
>> >Subject: [Sip-implementors] Required SDP content for G729A,
>> >G729AB, G729B
>> >
>> >Hi,
>> >
>> > Can anyone send me the SDP contents of how the SDPs will
>> >look like for a incoming INVITE messages(with SDP) from a UAC,
>> >which supports G729A & G729AB & G729B.
>> >
>> >Thanks,
>> >Sudhagar
>> >_______________________________________________
>> >Sip-implementors mailing list
>> >[email protected]
>> >https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>> >
>>
>> _______________________________________________
>> Sip-implementors mailing list
>> [email protected]
>> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>>
>> This email and any attached files herein contain information
>> that is intended only for the use of the individual or
>> entity to whom it is addressed and may contain information
>> that is legally privileged, confidential or otherwise exempt
>> from disclosure under applicable laws. If the reader of this
>> message is not the recipient, any disclosure, dissemination,
>> distribution, copying or other use or retention of this
>> communication or its substance is prohibited.
>>
>>
>>
>> _______________________________________________
>> Sip-implementors mailing list
>> [email protected]
>> https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
>>
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
