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Mitel Forums => MiVoice Office 250/Mitel 5000 => Topic started by: cahrens on October 28, 2021, 04:47:47 PM

Title: loop start lines won't release
Post by: cahrens on October 28, 2021, 04:47:47 PM

This customer switched providers recently and now I have a problem with calls not releasing properly. If the call is on hold and the outside caller hangs up, the call will not release. I have gone round and round with the provider and can't seem to get them to understand how this is supposed to work. Should get open loop (Positive disconnect) for 350 milliseconds.
I monitored the trunk to see what happens. When the caller hangs up I get a busy tone for about 5 seconds then silence for a couple of seconds then dialtone for about 20 seconds and back to reorder. I think this is considered CPC. Is there some setup in the 250 system that will respond to this?

Title: Re: loop start lines won't release
Post by: Tech Electronics on October 29, 2021, 08:30:22 AM

cahrens,

Call Party Control (CPC) should still have a Loop Disconnect at the end of the call and if you have a CPC Tester then put it on the line and see.

It has been a long time since I had to deal with POTS lines, but if you look at the timers in the MiVO-250 for IC-CO Disconnect is set to 600ms not 350ms. I believe that the 350ms time frame is for CO-CO Disconnect timer. Of course the timers are shown in hundredths of a second and not thousands of a seconds, but the conversion is pretty simple.

LS/GS (LS) CO-CO Disconnect: A call is disconnected by the system if it detects loss of loop current lasting longer than this timer during trunk-to-trunk calls.
LS/GS (LS) Dialing Disconnect: The connection is dropped if the system detects loss of loop current lasting longer than this timer during dialing.
LS/GS (LS) IC-CO Disconnect: A call is disconnected by the system if it detects loss of loop current (lasting longer than this timer) during station-to-trunk calls.

So, the CPC would have to drop Loop for more than 600ms before the system would see it as a disconnect and if you are telling them to put it to 350ms then the problem would be with the system not seeing it as a disconnect.

You could also read this article on Sandman.com (RIP): CPC Troubleshooting (https://www.sandman.com/knowledgebase/call-party-control-cpc-troubleshooting)

There are also devices you can put on the POTS line to provide a Loop Disconnect as well if you don't want to mess with the timers to find the sweet spot.

Thanks,

TE

Title: Re: loop start lines won't release
Post by: cahrens on November 01, 2021, 12:44:30 PM

I'll have to play some more with the timers. I think I tried changing the IC-CO disconnect timer to 35 but I will have to recheck.

Title: Re: loop start lines won't release
Post by: cahrens on December 07, 2021, 03:45:16 PM

The LS-GS CO-IC disconnect timer was  set at 60. Once I changed it to 35 the problem was resolved. Thanks!