codec values in SDP

[Istvan Balla]

Is there a site of IETF or ITU where rtpmap values in SDP for all audio codecs are listed?

I saw many sites of both organizations with examples in rtpmap, but those were not a complete list.

Are both G729 and G729A indicated 18 with annexb=no in rtpmap?

Can I distinguish G729 and G729A in SDP?

See below example:

v=0

o=CiscoSystemsSIP-GW-UserAgent 3016 6788 IN IP4 137.30.42.21

s=SIP Call

c=IN IP4 137.30.42.21

t=0 0

m=audio 16528 RTP/SAVP 18 101

c=IN IP4 137.30.42.21

a=rtpmap:18 G729/8000

a=fmtp:18 annexb=no

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-16

a=crypto:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

[Jitender Bhandari]

Hi Istvan,

See below 

https://en.wikipedia.org/wiki/RTP_audio_video_profile

(Rate if it helps)

JB

[HARIS_HUSSAIN]

See Below from RFC

https://tools.ietf.org/html/rfc3551#section-4.5.6

The speech coding
   algorithms in the main body of G.729 and in G.729 Annex A are fully
   interoperable with each other, so there is no need to further
   distinguish between them.  An implementation that signals or accepts
   use of G729 payload format may implement either G.729 or G.729A
   unless restricted by additional signaling specified elsewhere related
   specifically to the encoding rather than the payload format.

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[Istvan Balla]

Thanks for the answers.

Signalling peers:

8811 SIP phone--CUCM--isr4331 pstn gw

Media peers:

8811 SIP phone -- isr4331 pstn gw

In debug voip ccapi inout I see on ISR 4331 that call codec for media is 0x4 (g729) instead of 0x8 (g729A). I set voice card codec complex to medium but remained the same.

8811 advertises (from device pool) g729A, g729 and g729B. SIP trunk from CUCM 11.5 to pstn gw has the same codec list in thunk's device pool.

Anything else I can do on ISR 4331 to negotiate g729A (0x8)?

Thank you