One-way audio, cross-talking - rtp issue

Maciej Bylica · ‎10-26-2012

Hello,

We are encountering problem on Cisco 3945E with Version 15.2(1)T (c3900e-universalk9-mz.SPA.152-1.T.bin).

The problem is that we are getting one-way audio very often.

Call flow is like following:

CUSTOMER --> CISCO --> TERMINATOR.

After closer look into this, we've found that there is two-way audio between CISCO and TERMINATOR, but for some reason CISCO is not traversing this RTP to CUSTOMER. In other words, we do have:

RTP:

CUSTOMER ----> cisco ----> TERMINATOR

CUSTOMER noRTP cisco <--- TERMINATOR

SDP part of SIP properly points to RTP ports as well as IP addresses - no problem there.

Additionally two strage things appeared (apart from lack of RTP stream)

- instead of heaving defined codes with ptime=20ms (g711alaw bytes 160) Cisco is sending RTP stream ptime=10ms

- sometimes two audio calls are joined together (two voice calls cross-talking)

debug rtp all shows sa lot of data:

Oct 26 20:34:28.091: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port24752

Oct 26 20:34:30.920: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port27461

Oct 26 20:34:40.733: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port17705

Oct 26 20:34:41.823: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port18047

Oct 26 20:34:46.123: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port21643

Oct 26 20:34:47.233: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port18972

Oct 26 20:34:48.387: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port19147

Oct 26 20:35:04.942: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port26059

Oct 26 20:35:08.363: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port20465

Oct 26 13:51:37.618: //212634/10A80AE38B4F/SIP/Media/sipSPICompareStreams: Flags set for stream 1: RTP_CHANGE=No CAPS_CHANGE=No RSVP_ADDR_CHANGE=No RSVP_MEDIA_CHANGE=No

Oct 26 13:51:37.618: //212634/10A80AE38B4F/SIP/Media/sipSPICompareSDP: Flags set for call: NEW_MEDIA=No DSPDNLD_REQD=No IPIP_MEDIA=No

Oct 26 13:51:34.953: //212943/1704BE52BFEA/SIP/Media/sipSPIAddStream: Adding stream 1 of type voice+dtmf (callid 212943) to the VOIP RTP library

Oct 26 13:51:34.953: //212943/1704BE52BFEA/SIP/Media/sipSPISetMediaSrcAddr: Media src addr for stream 1 = 10.10.10.10

Oct 26 13:51:34.953: //212943/1704BE52BFEA/SIP/Media/sipSPIUpdateRtcpSession: sipSPIUpdateRtcpSession for m-line 1

Oct 26 13:51:34.953: //212943/1704BE52BFEA/SIP/Media/sipSPIUpdateRtcpSession: rtcp_session info

#011laddr = 10.10.10.10, lport = 17322, raddr = 0.0.0.0, rport=0, do_rtcp=FALSE

#011src_callid = 212943, dest_callid = -1, stream type = voice+dtmf, stream direction = RECVONLY

#011media_ip_addr = - , vrf tableid = 0 media_addr_type = 1

Oct 26 13:51:34.953: //212943/1704BE52BFEA/SIP/Media/sipSPIUpdateRtcpSession: No rtp session, creating a new one

Oct 26 13:51:34.953: //212943/1704BE52BFEA/SIP/Media/sipSPICreateRtpSession: stun is disabled

Oct 26 13:51:34.953: //-1/xxxxxxxxxxxx/SIP/Media/sipSPIUpdateRtcpSession: VQM: gccb=0x0, gccb->callId=0, ccb->ccCallID=212943

Oct 26 13:51:34.971: //212746/12C3209E8CD6/SIP/Media/sipSPISetMediaSrcAddr: Media src addr for stream 1 = 10.10.10.10

Oct 26 13:51:34.971: //212746/12C3209E8CD6/SIP/Media/sipSPIDoPtimeNegotiation: Offered ptime:40, Negotiated ptime:20 Negotiated codec bytes: 160 for codec g711alaw

Oct 26 13:51:34.971: //212746/12C3209E8CD6/SIP/Media/sipSPICompareStreams: stream 1 dest_port: old=17154 new=17154

Oct 26 13:51:34.971: //212746/12C3209E8CD6/SIP/Media/sipSPIGetNewLocalMediaDirection:

#011New Remote Media Direction = SENDRECV

#011Present Local Media Direction = SENDRECV

#011New Local Media Direction = SENDRECV

#011retVal = 0

Oct 26 13:51:34.971: //212746/12C3209E8CD6/SIP/Media/sipSPICompareStreams: Flags set for stream 1: RTP_CHANGE=No CAPS_CHANGE=No RSVP_ADDR_CHANGE=No RSVP_MEDIA_CHANGE=No

Oct 26 13:51:34.971: //212746/12C3209E8CD6/SIP/Media/sipSPICompareSDP: Flags set for call: NEW_MEDIA=No DSPDNLD_REQD=No IPIP_MEDIA=No

Oct 26 13:51:34.971: //212746/12C3209E8CD6/SIP/Media/sipSPIReplaceSDP: Main stream got changed & it's Flow Around

Oct 26 13:51:34.971: //212746/12C3209E8CD6/SIP/Media/sipSPIUpdCallWithSdpInfo

Lately we have more traffic going through Cisco gw. Before that there was no issue like that.

CPU Utilization is <20%

Could anybody have encountered similiar problem or could point me to right direction how to solve this.

Thx in advance.

Maciej

Maciej Bylica · ‎10-26-2012

more info:

debug rtp all

debug ip icmp

shows

Oct 26 23:54:16.312: ICMP: dst (10.10.10.10) port unreachable rcv from 20.20.20.20

Oct 26 23:54:16.312: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port21213

Oct 26 23:27:34.716: ICMP: dst (10.10.10.10) port unreachable rcv from 20.20.20.20

Oct 26 23:27:34.716: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port31577

where 10.10.10.10 is Cisco gw, 20.20.20.20 terminator

.pcap file shows that i am sender of this icmp message but also receiving this from Customer and Terminator.

ACL's turned off does not change anything....

Upgrading to 15.2.3 and downgrading 15.1.2 has no possitive result as well

Maciej Bylica · ‎10-27-2012

Guys could you please give me a hint where to look for an answer

Thx.

trdavid · ‎10-29-2012

Hi Maciej,

RTP issues of this type, provided that routing and network are OK for the packets to reach the destination and also because it seems it is an intermittent issue... well, this type of investigation may require debugs and pcaps in different points of the network, an insight into why it is intermittent and so on. Open a TAC case. It will ensure that solving your issue benefits of an assigned resource and a clear timeline for resolution.

Hope this helps. Cheers.

slashdots · ‎10-29-2012

I've came across to crosstalking.

In my case it has been Bug:

http://tools.cisco.com/Support/BugToolKit/search/getBugDetails.do?method=fetchBugDetails&bugId=CSCtw73602

In your situation I would open a TAC and asked specific for that bug. Because the affected IOS in my case is not listet in the Bug Toolkit. (Unfortunatly I don't know which IOS was affacted because I was not allowed to touch it, also I don't know what IOS the router is running now.)

Knowing this ist just a hint, I hope that helps anyway.

Maciej Bylica · ‎10-29-2012

Hello,

Many thanks for your feedback.

One thing is clear now....

Oct 26 23:54:16.312: ICMP: dst (10.10.10.10) port unreachable rcv from 20.20.20.20

Oct 26 23:54:16.312: :rtp_udp_unreachable:Entered: ICMP unreachable for dest port21213

is not a problem anymore.

Cisco is notyfying me that one/few last session RTP packets hit 20.20.20.20 just after the server teared down the connection. This is not an issue for me, because voice call is not affected.

Regarding one-way audio i am still investigating this issue .....

Daniele Giordano · ‎03-31-2013

Hi, I've same problems: crosstalk and one way audio.

https://supportforums.cisco.com/thread/2085359

Do you get a workaround from TAC?

Regards.

acampbell · ‎04-01-2013

Hi,

I came accross a similar issue last year.

Looking at the debugs etc above

The port/destination unreacables are highlighting
ODD port numbers like 21213,31577

ODD port numbers are used for RTCP and EVEN
port numbers should be for the RTP streams (See RFC 1889)

In my case the issue was being caused by a bug
in a Cisco PIX with NAT.

Hope this helps

Regards,
Alex.
Please rate useful posts.

Regards, Alex. Please rate useful posts.