atcomsystems.ca/forum Forums Other TDM Phone Systems Vertical Telephones & Systems MBX/XTS VoIP + Comcast

I have a customer with: main office has an MBX + Comcast PRI, VoIPed to 4 other sites, all of which have XTS + various providers. One of them uses Comcast PRI also. When they intercom over the VoIP, everything works fine EXCEPT when the main office is involved -- they are sometimes getting half-duplex conversations ("I hear them but they can't hear me"), and some dropped calls. There is no pattern to either failure - it is intermittent but ongoing.
Vertical Tech Support advises us to tell the customer "not to use Comcast, our equipment won't always work properly with their emulated PRIs".

Is there any fix for this?
Anyone having any success or complete failure with Comcast's emulated PRIs?

Thanks as always for your help.

I am a little confused here....you are networking via voip between an MBX and XTS ( I assume you are using the 12/24 port lan b cards in the XTSs) One of them uses a COMCAST pri..now is this for voice calls? This is not your voip connection is it? The PRI is for lines and possibly calls are being transferred to other locations across voip? In other words, can you provide a bit more information before I can reply about Comcast PRIS not working.

Thanks Derrick. Sorry, that was not clear. We had trouble with the PRI at first, a year ago, but it is now working, EXCEPT we cannot make DIDs (from the PRI) work. ?? Vertical does still advise us not to use Comcast emulated PRIs.

The MBX is VoIPed to (5) XTSs. These are on their WAN, and 2 sites are Comcast, including the one with MBX, which is the main office. The XTS VoIP calls work fine among themselves, but there are intermittent dropped calls whenever a VoIP call involves the MBX. Vertical tells us that this problem is always the network.

Is the problem simply that MBX won't VoIP with XTS?

I have never networked an MBX to an XTS so I can' t provide as much help as I would like to. I can tell you this that the XTS requires fp 4.1 and the 12 port lanb card to voip with an MBX OR SBX. SIP converted PRIS sometimes have issues but not did number problems. That is usually a parameter or routing problem. DID Routing as you have discovered is very different for the Xts than the MBX. I can help you there if you explain the issue in greater detail.

And only the XTS-IP FP 4.1 can be used to network to the MBX. The XTSc cannot be used. I had only one MBX to XTS network customer and we developed trouble after adding the MBX as a 5th location on the XTS network. I think it was because the VoIP network was not on a managed network at that stage of growth.