Yealink Forums

There is a typo in the SDP section of the INVITE packets this phone sends out. It has the incorrect RTPMAP value for PCMU/8000, of 8, which should be 0. 8 is the RTPMAP value for PCMA/8000. This results in the phone effectively offering PCMA twice in the invite and not offering PCMU at all.

From the SDP of the invite from this phone:

s=SDP data
c=IN IP4 10.66.30.149
t=0 0
m=audio 11780 RTP/AVP 8 9 8 105 102 104 103 18 106 101
a=rtpmap:8 PCMU/8000
a=rtpmap:9 G722/8000
a=rtpmap:8 PCMA/8000
a=rtpmap:105 G726-40/8000
a=rtpmap:102 G726-32/8000
a=rtpmap:104 G726-24/8000
a=rtpmap:103 G726-16/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no
a=rtpmap:106 iLBC/8000
a=ptime:20
a=sendrecv
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15


I have tested this on both 44.80.0.60 and 44.80.0.70 firmwares

Can you do a reset and check again?
It may be changed by autoprovision.

Regards,
James

If it's set up as a SIP account without auto provision the RTP maps are correct

m=audio 11782 RTP/AVP 9 0 8 18 101
a=rtpmap:9 G722/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCMA/8000


Is this a problem with autoprovision on the phone or do I need to doublecheck my provisioning code? I don't see this on other Yealink phones and I don't think we set anything with RTP maps different between your phone models on our end.

Same situation on Firmware 44.80.23.3, Surprised at this bug got past QA. ulaw and alaw hardly niche codecs.

You need to force an override using autoprovision template:

################################################################################​#######
## Audio Codec ##
################################################################################​#######

account.1.codec.1.enable = 1
account.1.codec.1.payload_type = PCMA
account.1.codec.1.priority = 1
account.1.codec.1.rtpmap = 8

account.1.codec.2.enable = 1
account.1.codec.2.payload_type = PCMU
account.1.codec.2.priority = 2
account.1.codec.2.rtpmap = 0