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ISDN E1 channels


ood afternoon,

I've a little issue with the synchronization of my E1 channels. In fact, I've 2911 router with an E1 controller connected to the PSTN provider. The GW is registered in MGCP - great this works.default my

By default my voice channels are from 1 - 15 and 17 - 31 but I really need to synch with our PSTN provider 1-30 channels. So I changed the Channel IE Type to Continuous Number.

But when I do some debugging on the gw with sh voice call summary, the channels are not well configured. It stays always in 1 - 15 and 17 - 31.

Could you please help me?

Super Bronze

Re: ISDN E1 channels


On an E1, channel 16 is ALWAYS the D-channel used for signalling.

So you cannot change this - and you don't need to. When somoeone refers to 'channels 1-30' they generally mean 'B-channels 1-30'.

All is well, so put your feet up.



Please rate helpful posts..

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

Re: ISDN E1 channels

Thanks for the information.

But tell me why I have not the same channel that is synchronized between

the Nortel GW and the Cisco GW.

Let's say a call is coming in on channel 1, I do a sh voice call summary and

I see channel 1 as well like usual.

When we arrive on channel 16, I can tell you we

are not anymore synchronized.

For instance, a call is coming on channel 26, I do

a voice call summary, I see channel 26 is busy. But the Nortel engineer say he is using channel 24. We have always this issue only when we are above the 15th channel.

I really don't understand. LOL

We have the calls OK when we are below 15 so I think the signaling is well working. What kind of Channel IE type do I need to setup?

Hall of Fame Super Gold

Re: ISDN E1 channels

Send configuration and "debug isdn q931" with "term mon" when you receive a call with troubloe. Also explain exactly what is happing.