Hi All,

I have Asterisk 11 talking to Avaya over SIP trunk using TLS and SRTP. On incoming calls from Avaya asterisk complains of ‘unsupported crypto parameters: UNENCRYPTED_SRTCP’ and rejects the call with ‘488 Not acceptable here’

Doesn’t Asterisk support UNENCRYPTED_SRTCP as crypto parameters in sdp?

FYI SDP looks like this.

v=0
o=- 1429194215 1 IN IP4 XX.XX.XX.XX
s=-
c=IN IP4 XX.XX.XX.XX
b=TIAS:64000
t=0 0
a=avf:avc=n prio=n a=csup:avf-v0
m=audio 50096 RTP/SAVP 0 18 120
a=rtpmap:0 PCMU/8000
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=no a=rtpmap:120 telephone-event/8000
a=ptime:20
a=crypto:1 AES_CM_128_HMAC_SHA1_80
inline:zUVSWsFB/WjVtLxXojBT7zbNvuQ4BkOwcCkD/AjM|2^20 UNENCRYPTED_SRTCP

And on CLI I see,

DEBUG[1568][C-00000000] sip/sdp_crypto.c: local_key64
7vXot5kn/sl/GYv5ENN6yW0PZZapQ00c++biLgoX len 40
WARNING[1568][C-00000000] sip/sdp_crypto.c: Unsupported crypto parameters:
UNENCRYPTED_SRTCP
DEBUG[1568][C-00000000] chan_sip.c: Processing media-level (audio) SDP
a=crypto:1 AES_CM_128_HMAC_SHA1_80
inline:zUVSWsFB/WjVtLxXojBT7zbNvuQ4BkOwcCkD/AjM|2^20 UNENCRYPTED_SRTCP… UNSUPPORTED OR FAILED. WARNING[1568][C-00000000] chan_sip.c: Rejecting secure audio stream without encryption details: audio 50096 RTP/SAVP 0 18 120
VERBOSE[1568][C-00000000] chan_sip.c:
<--- Reliably Transmitting (NAT) to XX.XX.XX.XX:5061 --->
SIP/2.0 488 Not acceptable here

Thanking in advance for any inputs.

–Satish