One of my clients has a CTX670 that his phone vendor has put BIPUs in and now says it is doing Qsig across the network? The problem is that calls are being 'dropped' frequently. This vendor is blaming the network, yet calls are being dropped at the District Office as well that don't even touch the network.

As the network vendor, I am trying to set QoS but neither the client nor the vendor can tell me how the Toshiba is marking packets. From my investigations, it seems that this system is not really doing VoIP - he uses the same phones he always has and my QoS doesn't pick up anything even when tuned to the IPs of the phone systems.

Can anyone explain any of this to me? What marking is the PBX using to set ToS on the packets? My fair expereince with VoIP is that the when the network is causing problems it results in stutter, 'in-a-barrel' and that kind of thing given connectivity?

Any insight into this BIPU and how it is working woudl be a big help. This phone vendor has lost every contract in this area due to sloppy work and refuses to up any info.

Thank you in advance.