atcomsystems.ca/forum Forums TDM Business Telephone Systems Mitel Telephones & Systems After forwarding external call to external line stays open

I just installed AT&T Home Wireless on to my Mitel SX 50, everything seems to be working. The only problem I have if I receive a external phone call and I forward it to an external phone number, everything works, but after both parties hang up, the lines stay open, I have to force release both of the lines. Somehow AT&T Home Wireless, does not send the correct information to Mitel SX 50 that the phone call has ended. Is there any way I can program SX 50 to notice that the phone call has ended.

Thank you already for your help.

Loop supervision is required in order for the SX-50 (or any phone system for that matter) to release a call when the calling party hangs up. This is offered on traditional copper lines, but often is not provided on "fake" lines that are created by ATAs, EMTAs, etc.

It called CPC control (Calling Party Control). If AT&T can't provide it, Viking Electronics makes a device CPC-1 for 1 line or CPC-4 for 4 lines that will do it.

Rcaman

Try setting your dis-connect timer to the minimum of 60ms.
That will make the trunks more sensitive to disconnects.

Thank you so much for this information, I got a CPC control for each line and everything is working now. Thank you again for the information.

Great. Thanks for letting us know the outcome.