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New Member

German ISDN problems

I have recently installed a 2851 voice gateway with ios 12.3(11)T10 with an E1 connection in Germany. We run CM4.1(3).

There are complaints that sometimes calls don't come through to internal extensions, from both staff and clients. There are also reports that the call success depends on the speed of dialling.

I have seen calls coming in with 9 digits presented rather than 10 (I have worked round this by a translation rule) but am still worried that calls are getting dropped or rejected by the gateway.

I've spoken with a German telecom engineer and he thinks its to do with pulse dialling and the gateway accepting calls that aren't fully dialled.

Any ideas would be extremely helpful as this is becoming a serious problem.



Re: German ISDN problems

Can you pull a debug isdn q931 output from the router for a failed call ?

Are you using Overlap send receive ?

Is this a MGCP or h323 gateway?

New Member

Re: German ISDN problems

Gateway is H323.

Haven't been able to replicate a failed call to get a q931 debug. Will set up a syslog connection and see if that catches it.

Have tried overlap with T301 2000, seemed to have no effect. (Is it for calls in both directions?description seems to imply its for outbound.)