hi.. we have a voip network with a major carrier connection for international call. we are having a few minor problem where the caller can hear but the receiver cannot.. we talked with the carrier and they claim that our compression may be an issue and that we should try to compress less.. we use G723.1 high.. can this be a problem? it doesnt happen all the time but a few everyday.. any comments..id appreciate it
One way voice can have nothing to do with compression. A faulty DSP card on a certain gateway could however cause this. A couple of other possibilites are that voice packets (RTP/UDP) are being blocked in one direction by a firewall or router access list for certain calls. Another is that the speech path is not being cut through correctly in the forward direction. It could, depending on the architecture in use, even be a basic routing problem somewhere (call signalling is routed OK but RTP stream between certain GWs not so).
If you are using Cisco they have a useful article on their website for troubleshooting one-way voice.
thanks for the reply…
we dont have much problem within the network itself.. like from Gateway to Gateway but this problem is for certain int’l calls.. we have an architecture as followed:
several gateways in various cities connected to main gateway.. from main gateway to int’l GW with carrier T1 line connection.. we use Korean Gateways with cisco routers. we are presuming it’s a carrier problem.. what do you think?