Home > Problems > One Way Voice

Problem: One Way Voice

It is possible for a call to be established but the voice path to be not present. This may be due to a problem with signaling or the route taken by voice packets (see No Voice Path for more details).

Other causes of one-way voice can include DSP hardware faults or DSP software "hanging".

Impact

No voice path is present in one direction.

Resolution

If the problem appears to be associated with all calls going through a specific route or router then it is likely to be associated with a router problem, a firewall blocking voice packets or NATs. Check the Call Manager/ Gatekeeper/ SIP Proxy for indications of signaling problems. Use traceroute or ping from each endpoint to verify the packet path. Use a VoIP network analyzer to decode signaling and investigate problem.

If the problem appears to be associated with a specific port, device or a TDM trunk interface on a gateway then it is likely to be related to the DSP. Check the DSP status for the specific Gateway to verify correct operation.

Back To Top

Conditions of use: The material on this site is copyright VoIP Troubleshooter LLC and may be freely used but not copied or downloaded.  In making use of this site the user acknowledges that VoIP Troubleshooter LLC or Contributor has no liability for any issues or problems that may arise directly or indirectly as a result of such use.  VoIP Troubleshooter LLC and Contributor are providing this material as-is with no warranty as to correctness or completeness and do not accept any responsibility for any issues or problems of any nature whatsoever that may arise from the use of the material on this site.