And this is a sample from the RTPEngine logfile showing a failed call:

 

##### Call 2 - One way audio #####

Feb  6 16:16:07 kamailio rtpengine[22145]: Got valid command from 127.0.0.1:42444: offer - { "sdp": "v=0

o=TimDesk1 8000 8000 IN IP4 192.168.1.105

s=SIP Call

c=IN IP4 192.168.1.105

t=0 0

m=audio 22016 RTP/SAVP 8 13 0 9 2 101

a=sendrecv

a=rtpmap:8 PCMA/8000

a=ptime:20

a=rtpmap:13 CN/8000

a=rtpmap:0 PCMU/8000

a=rtpmap:9 G722/8000

a=rtpmap:2 G726-32/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:XZZ8Fvj4Zl49zkY8ITDlLbOxKLdd+LXWLJBd0L9N|2^32

a=crypto:2 AES_CM_128_HMAC_SHA1_32 inline:AB3kfDPcdZk6smiB7omx07ZkhN8b4tfRuANhFtMg|2^32

", "direction": [ "external", "internal" ], "replace": [ "origin", "session-connection" ], "transport-protocol": "RTP/AVP", "call-id": "848952795-14407-221@BJC.BGI.B.BAF", "received-from": [ "IP4", "86.188.176.25" ], "from-tag": "2103788516", "command": "offer" }

 

Feb  6 16:16:07 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF] Creating new call

 

Feb  6 16:16:07 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF] Opened ports 47790..47791 for media relay

 

Feb  6 16:16:07 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF] Opened ports 47806..47807 for media relay

 

Feb  6 16:16:07 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF] Returning to SIP proxy: d3:sdp553:v=0

o=TimDesk1 8000 8000 IN IP4 172.16.52.71

s=SIP Call

c=IN IP4 172.16.52.71

t=0 0

a=ice-lite

m=audio 47790 RTP/AVP 8 13 0 9 2 101

a=rtpmap:8 PCMA/8000

a=ptime:20

a=rtpmap:13 CN/8000

a=rtpmap:0 PCMU/8000

a=rtpmap:9 G722/8000

a=rtpmap:2 G726-32/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

a=sendrecv

a=rtcp:47791

a=ice-ufrag:k2elgesL

a=ice-pwd:MatMz0J3a3xFc87Tok0ykF8EFlYU

a=candidate:hgovvroVet3HALus 1 UDP 2130706431 172.16.52.71 47790 typ host

a=candidate:hgovvroVet3HALus 2 UDP 2130706430 172.16.52.71 47791 typ host

6:result2:oke

 

Feb  6 16:16:13 kamailio rtpengine[22145]: Got valid command from 127.0.0.1:37264: answer - { "sdp": "v=0

o=CiscoSystemsSIP-GW-UserAgent 2893 6808 IN IP4 172.16.52.4

s=SIP Call

c=IN IP4 172.16.52.4

t=0 0

m=audio 18680 RTP/AVP 8 101

c=IN IP4 172.16.52.4

a=rtpmap:8 PCMA/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

a=ptime:20

", "direction": [ "internal", "external" ], "replace": [ "origin", "session-connection" ], "transport-protocol": "RTP/SAVP", "call-id": "848952795-14407-221@BJC.BGI.B.BAF", "received-from": [ "IP4", "172.16.52.4" ], "from-tag": "2103788516", "to-tag": "901A2AA1-13C0", "command": "answer" }

 

Feb  6 16:16:13 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF] Returning to SIP proxy: d3:sdp587:v=0

o=CiscoSystemsSIP-GW-UserAgent 2893 6808 IN IP4 123.123.123.123

s=SIP Call

c=IN IP4 123.123.123.123

t=0 0

a=ice-lite

m=audio 47806 RTP/SAVP 8 101

c=IN IP4 123.123.123.123

a=rtpmap:8 PCMA/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

a=ptime:20

a=sendrecv

a=rtcp:47807

a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:oej4VLwO5K/OvjXVKH9Qg9dECCqjCAVd2zvu4Au5

a=ice-ufrag:xKKraWbi

a=ice-pwd:5VaewbH0SMYob82Mln1hMs4hbMJl

a=candidate:TUErwQDNDzRhCQkj 1 UDP 2130706431 123.123.123.123 47806 typ host

a=candidate:TUErwQDNDzRhCQkj 2 UDP 2130706430 123.123.123.123 47807 typ host

6:result2:oke

 

Feb  6 16:16:15 kamailio rtpengine[22145]: Got valid command from 127.0.0.1:39817: answer - { "sdp": "v=0

o=CiscoSystemsSIP-GW-UserAgent 2893 6808 IN IP4 172.16.52.4

s=SIP Call

c=IN IP4 172.16.52.4

t=0 0

m=audio 18680 RTP/AVP 8 101

c=IN IP4 172.16.52.4

a=rtpmap:8 PCMA/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

a=ptime:20

", "direction": [ "internal", "external" ], "replace": [ "origin", "session-connection" ], "transport-protocol": "RTP/SAVP", "call-id": "848952795-14407-221@BJC.BGI.B.BAF", "received-from": [ "IP4", "172.16.52.4" ], "from-tag": "2103788516", "to-tag": "901A2AA1-13C0", "command": "answer" }

 

Feb  6 16:16:15 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF] Returning to SIP proxy: d3:sdp587:v=0

o=CiscoSystemsSIP-GW-UserAgent 2893 6808 IN IP4 123.123.123.123

s=SIP Call

c=IN IP4 123.123.123.123

t=0 0

a=ice-lite

m=audio 47806 RTP/SAVP 8 101

c=IN IP4 123.123.123.123

a=rtpmap:8 PCMA/8000

a=rtpmap:101 telephone-event/8000

a=fmtp:101 0-15

a=ptime:20

a=sendrecv

a=rtcp:47807

a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:oej4VLwO5K/OvjXVKH9Qg9dECCqjCAVd2zvu4Au5

a=ice-ufrag:xKKraWbi

a=ice-pwd:5VaewbH0SMYob82Mln1hMs4hbMJl

a=candidate:TUErwQDNDzRhCQkj 1 UDP 2130706431 123.123.123.123 47806 typ host

a=candidate:TUErwQDNDzRhCQkj 2 UDP 2130706430 123.123.123.123 47807 typ host

6:result2:oke

 

Feb  6 16:16:16 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF port 47806] Discarded invalid SRTP packet: authentication failed

 

Feb  6 16:16:19 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF port 47790] Confirmed peer address as 172.16.52.4:18680

 

Feb  6 16:16:19 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF port 47806] Confirmed peer address as 86.188.176.25:22016

 

Feb  6 16:16:19 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF port 47806] No support for kernel packet forwarding available

 

Feb  6 16:16:19 kamailio rtpengine[22145]: [848952795-14407-221@BJC.BGI.B.BAF port 47790] No support for kernel packet forwarding available

 

If anyone has any ideas, please let me know.

 

From: sr-users [mailto:sr-users-bounces@lists.sip-router.org] On Behalf Of Tim Chubb
Sent: 07 February 2015 08:10
To: Kamailio (SER) - Users Mailing List
Subject: [SR-Users] RTPEngine Intermittent One Way Audio Issue SRTP => RTP

 

Hi,

 

I am currently experiencing an intermittent one way audio issue, when using RTPEngine and proxying between srtp  and rtp.  There is no apparent pattern, I have managed to repeat the  on the 7th, 23rd, and 63rd calls to a test number, where upon connection only audio in the RTP => SRTP direction was working.  All other test calls worked as normal.  Digging through the RTPEngine log file the only abnormalities I can see are: Discarded invalid SRTP packet: authentication failed entries on the calls that had the one way audio issue. 

 

What could be causing this?

 

Thanks

 

Tim.