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New Member

Issues with busy signals on incoming calls

I have a CME unit installed with a partial T1 or 11 channels. They have about 15 people so I think the ratio is OK. I am having issues where people are getting busy signals calling into the system as well as internel people calling 4 and 10 digit internal numbers. I have CFB and CFNA set up on all accounts. I also have 2 line apperances for each DID. Any help would be great and what might be the best commands for debug for this issue.

Also we are using a NM-CUE card with 8 ports.


New Member

Re: Issues with busy signals on incoming calls

Are you getting busy signals when trying to call internal extensions immediately or does the phone ring and then try to use the CFNA setting?

New Member

Re: Issues with busy signals on incoming calls

Do "debug isdn q931" on the router and make an incoming call. Check to see which channel is being used for the call. With partial T1 the telco may be trying to seize a channel at the high end of the range (Bottom Up) and your CME is only answering at the low end (Top Down). One way to quality this is to get on the voice port and configure it for "isdn bchan-number-order ascending" or "isdn bchan-number-order ascending". For T1 circuits this issue rarely comes up because no one cares what channel is being seized except if you're dealing with a glare issue. Here it matters.


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