VOIP call rings, user answers but no sound

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Jun 26th, 2009
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I have set up VOIP between to sites.

Each site connects from a PBX to router then accross the WAN.

Site A calls site B, phone rings, user answers but there is no sound at either end!!! complete silence.

Can anyone help

Thanks in advance

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Prathyush Keeriyatt Mon, 06/29/2009 - 09:25
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No way audio occurs due to the following reasons:

- NAT, PAT and firewalls blocking UDP traffic exist b/w the endpoints.

- Troubles in IP connectivity.

Please check these and revert

franpena2008 Thu, 02/17/2011 - 23:47
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I do not see firewalls denying udp traffic in the firewalls

Ip connectiviy is seems to be OK. I can ping ip phones from the gateway.

Signaling between ip phones and DECT phones is also OK but cannot hear voice. is the gateway and remote ip phone.

F10R248#sh voip rtp connections
VoIP RTP active connections :
No. CallId     dstCallId  LocalRTP RmtRTP LocalIP                                RemoteIP                         

10  153541     153540     16388    25520                  

F10R248# sh log | i

Feb 17 10:22:53.196: voip_rtp_create_session: callID=151269, dstCallID=151268 laddr=, lport=16446,raddr=, rport=27792, type=3, sig_tos=3, ip_tos=5
Feb 17 10:22:53.216: RTP(15494): ps rx s=, d=, pt=18, ts=C60800, ssrc=963B6251, marker=1
Feb 17 10:22:53.228: RTP(9961): fs tx s=, d=, pt=96, ts=9EA4A8BD, ssrc=174E65F8, marker=1
Feb 17 10:22:53.236: RTP(15495): fs rx s=, d=, pt=18, ts=C608A0, ssrc=963B6251, marker=0
Feb 17 10:22:53.252: RTP(9962): fs tx s=, d=, pt=96, ts=9EA4A95D, ssrc=174E65F8, marker=0
Feb 17 10:22:53.256: RTP(15496): fs rx s=, d=, pt=18, ts=C60940, ssrc=963B6251, marker=0
Feb 17 10:22:53.272: RTP(9963): fs tx s=, d=, pt=96, ts=9EA4A9FD, ssrc=174E65F8, marker=0
Feb 17 10:22:53.276: RTP(15497): fs rx s=, d=, pt=18, ts=C609E0, ssrc=963B6251, marker=0

Ming Yuan Chiu Tue, 03/01/2011 - 13:46
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Can you post configuration on the switchport for the phone that it is connected to and also post snippet of the voice configuration on the router.


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