One Way Audio

From BGNV Wiki

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 audio can include DSP hardware faults or DSP software "hanging".

[edit] Impact

No voice path is present in one direction.

[edit] 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.