A colleague recently asked the question, "Does anyone know the supported a/v codecs in Messenger for Mac 7.0.2?"

 

The list of codecs supported by any SIP client is always included in the SIP INVITE message sent by the client when it initiates a call. The only thing needed to answer this specific question is a copy of the SIP INVITE message sent by Mac Messenger and it's actually quite easy to do if you also have access to an Office Communicator client. Messenger itself does not log the INVITE message, but OC logs all INVITE messages it receives (and more.)  This information can be found in OC's .uccapilog files, %USERPROFILE%\Tracing\Communicator-uccapi-0.uccapilog or %USERPROFILE%\Tracing\Communicator-uccapi-1.uccapilog. (These are plain text files.)

 

Below is the actual SIP INVITE message sent from Mac Messenger.  In the INVITE Mac Messenger includes a list of all audio and video codecs it supports.  The audio codecs are highlighted in green and the video codecs are highlighted in blue.  Hopefully these tables I created are easier to read and understand.

 

Table 1: Mac Messenger supported audio codecs

Payload Type

Encoding Name

Sampling Rate (Hz)

114

x-msrta

16000

RTAudio wide-band

111

SIREN

16000

Siren

112

G7221

16000

G.722.1

115

x-msrta

8000

RTAudio narrow-band

4

G723

8000

G.723

3

GSM

8000

GSM

8

PCMA

8000

G.711 A-Law

0

PCMU

8000

G.711 μ-Law

97

RED

8000

Redundant Audio Data

101

telephone-event

8000

Out of band DTMF

 

 

Table 2: Mac Messenger supported video codecs

Payload Type

Encoding Name

Sampling Rate (Hz)

121

x-rtvc1

90000

RTVideo

34

H263

90000

H.263

 NOTE: Due to a bug in Mac Messenger it falsely advertises support for the H.263 video codec.

 

Table 3: Mac Messenger SIP INVITE message

INVITE sip:157.54.78.92:49173;transport=tls;ms-opaque=41e5ce41ec;ms-received-cid=4451400 SIP/2.0

Record-Route: <sip:tk5ucdfpl01.exchange.corp.microsoft.com:5061;transport=tls;ms-fe=TK5UCDFPL01F03.exchange.corp.microsoft.com;opaque=state:T:F:Ci.R4451400;lr;ms-route-sig=bb4-_zJxlYamt3DRVIKFwcMvEsRaTQTD4WaGzvvuEqkzQbfvzLQdK2UgAA>;tag=3C9859557AD68F18E32CA083B80B493B

Via: SIP/2.0/TLS 157.54.62.135:5061;branch=z9hG4bKF202A1D2.CBFC7E1B9BC5B75D;branched=TRUE;ms-internal-info="atRgLzIW9S1ym0tzACTTUClDWrMsqP_3cBk-TBvQxq58EbfvzLL8oXogAA"

Authentication-Info: TLS-DSK qop="auth", opaque="91E9990A", srand="98EC05D9", snum="2027", rspauth="9644fa43bdd48afa6c8fdf8355d25670bf4585b6", targetname="TK5UCDFPL01F03.exchange.corp.microsoft.com", realm="SIP Communications Service", version=4

Max-Forwards: 69

Content-Length: 2610

Via: SIP/2.0/TLS 10.80.21.57:1216;received=157.54.78.92;ms-received-port=44278;ms-received-cid=47C8300

P-Asserted-Identity: "User A"<sip:usera@microsoft.com>

From: "User A"<sip:usera@microsoft.com>;tag=d03d8840ce;epid=d87ccbd605

To: <sip:userb@microsoft.com>;epid=b13b046d76

Call-ID: 13569aea201ac54faf45c6b6fefe17c

CSeq: 1 INVITE

Contact: <sip:usera@microsoft.com;opaque=user:epid:mhNBMViT31a4QksQCG-QHAAA;gruu>

User-Agent: UCCP/2.0.6362.0 MM/7.0.4663.2 (Mac Messenger 7.0.2)

Ms-Conversation-ID: AcrFaSvM3cpEGgc4VUa5ofpbE8Z/yA==

Supported: timer

Supported: ms-sender

Supported: ms-early-media

ms-keep-alive: UAC;hop-hop=yes

Supported: ms-conf-invite

Content-Type: application/sdp

History-Info: <sip:userb@microsoft.com>;index=1

v=0

o=- 0 0 IN IP4 10.80.21.57

s=session

c=IN IP4 10.80.21.57

b=CT:9980

t=0 0

m=audio 58387 RTP/AVP 114 111 112 115 4 3 8 0 97 101

k=base64:IbVi59CuaSZjzjZA8rmcH5Fvtj55lii2Ri5F7RZismxfb+UOgKtijPCMdvRN

a=candidate:je+Ii5f85jxUvR68WQSR1Bglvic9dF7TZ4zv9zzRaW8= 1 VLtghjZpi6oMjUFhKz3q1A== UDP 0.850 10.80.21.57 58387

a=candidate:je+Ii5f85jxUvR68WQSR1Bglvic9dF7TZ4zv9zzRaW8= 2 VLtghjZpi6oMjUFhKz3q1A== UDP 0.850 10.80.21.57 7116

a=candidate:6TGC3P5HA1jqAthJurO3b+I8HNWEFvcFh4y3MsvrfAU= 1 dJUXSPgZ1k1kSxUDSDahFw== TCP 0.190 131.107.1.57 57152

a=candidate:6TGC3P5HA1jqAthJurO3b+I8HNWEFvcFh4y3MsvrfAU= 2 dJUXSPgZ1k1kSxUDSDahFw== TCP 0.190 131.107.1.57 57152

a=candidate:Ruf+xAQ3I+LyehYtr8dT6tMVWRe9Tu++qoF8oXSs65c= 1 dzQjL1rpS84yst7u32vA7A== UDP 0.490 131.107.1.57 52993

a=candidate:Ruf+xAQ3I+LyehYtr8dT6tMVWRe9Tu++qoF8oXSs65c= 2 dzQjL1rpS84yst7u32vA7A== UDP 0.490 131.107.1.57 50584

a=cryptoscale:1 client AES_CM_128_HMAC_SHA1_80 inline:Y1QoAtj5fZUIWuJJEVHMUtV76vjCGXtJzUvOz3Ju|2^31|1:1

a=crypto:2 AES_CM_128_HMAC_SHA1_80 inline:a0QVJztOMHw+LwEPufs7ZcXXY0UijFHgAh8GNriO|2^31|1:1

a=maxptime:200

a=rtcp:7116

a=rtpmap:114 x-msrta/16000

a=fmtp:114 bitrate=29000

a=rtpmap:111 SIREN/16000

a=fmtp:111 bitrate=16000

a=rtpmap:112 G7221/16000

a=fmtp:112 bitrate=24000

a=rtpmap:115 x-msrta/8000

a=fmtp:115 bitrate=11800

a=rtpmap:4 G723/8000

a=rtpmap:3 GSM/8000

a=rtpmap:8 PCMA/8000

a=rtpmap:0 PCMU/8000

a=rtpmap:97 RED/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-16

a=encryption:optional

m=video 33899 RTP/AVP 121 34

k=base64:c1KpLxvyOBwTkxObxGbM5/T/92eNPL1suudZz4ZJS6346iw9d0qGg1Kb4ZPW

a=candidate:5rmNWe1cU+Owb+QZ76x6fROb8uMbIyVzLh/OQsVUyfc= 1 PscIxRsaqXrUQVOuo42BjQ== UDP 0.860 10.80.21.57 33899

a=candidate:5rmNWe1cU+Owb+QZ76x6fROb8uMbIyVzLh/OQsVUyfc= 2 PscIxRsaqXrUQVOuo42BjQ== UDP 0.860 10.80.21.57 19289

a=candidate:M/7iwQUrB0ngkoxf/UUC1Ocuk1iCqhhbvef4YdrlPIk= 1 xVH2G5iIsww0uLyjzVL4DA== TCP 0.190 131.107.1.57 51814

a=candidate:M/7iwQUrB0ngkoxf/UUC1Ocuk1iCqhhbvef4YdrlPIk= 2 xVH2G5iIsww0uLyjzVL4DA== TCP 0.190 131.107.1.57 51814

a=candidate:/+VdY9b+Vd7y5EKRyfumiHH43MXBhAMy/8+gbhzebqw= 1 whXNxWV7Ix6Sey0D3U6EzQ== UDP 0.490 131.107.1.57 50891

a=candidate:/+VdY9b+Vd7y5EKRyfumiHH43MXBhAMy/8+gbhzebqw= 2 whXNxWV7Ix6Sey0D3U6EzQ== UDP 0.490 131.107.1.57 54712

a=cryptoscale:1 client AES_CM_128_HMAC_SHA1_80 inline:V4nu6wpePiJq3IyOCqooD1lqbBGw6KTpnTSGQZD/|2^31|1:1

a=crypto:2 AES_CM_128_HMAC_SHA1_80 inline:ekLWCZeleOOgrdXVl9VPeNg08r4qlmZ9uDcMRuAE|2^31|1:1

a=maxptime:200

a=rtcp:19289

a=rtpmap:121 x-rtvc1/90000

a=rtpmap:34 H263/90000

a=encryption:optional