connection issues : receiving video calls

[Meelap]

Dear All,

We are facing following problems and have not been able to sort it out since last 2 months. Earlier such problem never occured.

Local / National ( we are in Mumbai and we easily get calls from other indian cities) video calls are easily received by us on ISDN. We use (MTNL is our service provider) isdn network and POLYCOM viewstation codec since last 6 years. Mostly we can not receive International video calls from other countries such as UK , USA etc. The funny part is that sometimes we do receive but the precentage is very low .... say that's twice in ten times. On the other hand we are able to connnect to them everytime if we initiate the call even at 384 Kbps . We spoke to MTNL officers but they are not sure why this has suddenly started
happening. I request all the members to express their view , opinions and remedies if possible ! thanks and waiting anxiously for response.

[Joe Vallender]

We had that issue where our US based customer had trouble terminating data calls (video) to sites in India. We traced the calls to the gateway handoff in India and the problem seemed to be in the long distance/local network from the international gateway switch to the local switches to the customer site. Since there are probably different telephone companies involved you should open a trouble case with your local provider and have them see if they are receiving the incoming calls and from who and over what kind of trunks. If they have a test ISDN number or T108 loopback post it here and I can make some test calls.
For your outgoing calls the route is probably completely different and whatever changed in the network routing has affected only incoming calls.

[vbhere]

Joe is correct.

From what you described the call path is as follows:

You are provisioned to an IXC through your LEC. The IXC dials through their international gateway with the routing being a function of the international dial code used. One country's gateway connects to another country's gateway per the international code used. All of this happening successfully is dependent on IXC's having international agreements with each other as well as goverments from each country involved.

So if you are able to dial out at any time you wish from Mumbai to another country it means the agreements with your provisioned IXC in India and the other the international IXC is fine outbound.

However, if another country try's to dial you there is an issue with the handoff either between your country's international gateway and your country's IXC (could be international agreements) or a handoff issue when the IXC gives the call to the LEC. I would lean to the former.