PRI channel remain consume even if phone gets powered off on call

Unanswered Question
Jun 10th, 2010

Hi,

Devices:-
CUCM 7.1.3
Cisco Router 2921 as MGCP gateway.
Cisco IP phone 6921 & 7911.

Problem:-
If IP phone gets abruptly powered off when it is on call with other PSTN party, the call does not get terminated at router & PSTN party remains on call.

Thus PRI channel still remain consumed at router (PRI gateway).

So what should be configured so that PRI channel does not remain consumed when above scenario occurs.

Thanks,
Abhas Jain

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Loading.
Paolo Bevilacqua Thu, 06/10/2010 - 09:06

I think you have failed to mention that is such a scenario, eventually the PSTN party realizes that line has dropped, hangs up and the channel is released.

Or you are in one of these countries where the calling party can hang up and the call does not clear ?

abhasjain Sun, 06/13/2010 - 02:18

HI,

Yes channel gets released if other party hang up the call.

Please suggest configuration so that channel is released within few second of phone getting powered off even if other party does not disconnect the call in mentioned scenario.

Thanks,

Abhas Jain

abhasjain Mon, 06/14/2010 - 00:34

Hi,

As of now more than 1000 users are using adapters. So,please suggest configuration so that PRI channel is released within few second of phone getting powered off as per mentioned call scenario.

Thanks,

Abhas Jain

tomecktomeck Mon, 06/14/2010 - 10:21

What about

time-out wait-release

setting to a lower value (1?) than the default one (30 sec I suppose).

abhasjain Mon, 06/14/2010 - 23:13

Hi,

I tried the command but did not worked.

I believe that there should be some configuration so that as soon as CUCM detects that phone is not reachable (power off) it will inform gateway to release the corresponding PRI channel.

Please suggest what need to be configured for the same.

Regards,

Abhas Jain

Aaron Harrison Mon, 06/14/2010 - 23:45

Hi

You could try 'mgcp rtp unreachable timeout':

http://www.cisco.com/en/US/docs/ios/12_3t/voice/command/reference/vrht_m2_ps5207_TSD_Products_Command_Reference_Chapter.html#wp1362166

However - I would say that a phone dropping off the network should be a rare event. Rather than trying to mask that problem, if you have areas of the network prone to power outages I would suggest you look into resolving those. It may be a case of providing UPS-backed power for the handsets of the main phone users (either out on the floor with the power adapters, or by putting in a PoE injector backed by UPS instead).

Regards

Aaron

abhasjain Tue, 06/15/2010 - 04:08

Hi,

I tried mentioned command but it did not worked.

Also observed one more point :- IP phone to IP phone call is going and both the calls are on LAN, if one IP phone goes power off the the other  IP phone still shows connected on call. After few seconds temp fail displays on the IP phone.

While this scenario in CUCM the powered off phone becomes unregistered.

I feel that CUCM should detect that one phone has been powered off, so that call should be terminated automatically.

Please suggest any configuration changes required to achieve required CUCM behaviour.

Regards,

Abhas Jain

Aaron Harrison Tue, 06/15/2010 - 04:11

Hi

Well - if one phone goes unregistered, this does not mean that the conversation has stopped.

It may just mean that one phone can no longer reach CCM due to some other issue, but may still be able to route to the device with which the RTP is being sent to... so CCM wouldn't terminate a call, it would leave it to the endpoints to decide.

How long is it before the PRI channel is released at present?

Aaron

abhasjain Tue, 06/15/2010 - 07:27

Hi,

Call remain connected untill the other party on PSTN disconnets it. Even call remain connected till 20 min & got disconnected only after PSTN party disconnects it.

Regards,

Abhas Jain

abhasjain Tue, 06/15/2010 - 23:02

Hi,

There are more than 1000 phones working on power adapter & some gets powered off due to loose connection. Resolving this issue using POE or other solution will take time.

Thus if some cconfiguration can help to release the PRI channel automatically as phone gets powered off will be better.

Regards,

Abhas Jain

Actions

This Discussion