CUCM - Dropped calls via MGCP

[Pascal Douce]

Hi Guys,

I'm currently facing an issue where calls to a 7962G are getting dropped. This is an intermittent situation and there is no flow or time which will indicate when the call will drop.

I've gathered the CDRs corresponding to the time when a call was last dropped and noticed the following :

Calling party : 43207XX

Called Party : 40691XX

DATE TIME ORIGINATION : 08:22

DATE TIME CONNECT : 08:22

DATE TIME DISCONNECT : 08:23

Duration : 72 seconds

Call flow : PSTN -> MGCP Gateway -> CUCM -> Phone

Orig Cause Location : 2 (No route to specified transit network(national use)

Orig Cause Value : 16 (Normal Call clearing)

Destination Cause Location : 0 (No error)

Destination Cause Value : 0 (No error)

Calling party : 43207XX

Called Party : 40691XX

DATE TIME ORIGINATION : 08:23:51

DATE TIME CONNECT : 08:23:54

DATE TIME DISCONNECT : 08:23:54

Duration : 0 second

Call flow : PSTN ->MGCP Gateway -> CUCM -> Phone

Orig Cause Location : 0 (No error)

Orig Cause Value : 47 (Resource unavailable)

Destination Cause Location : 0 (No error)

Destination Cause Value : 47 (Resource unavailable)

I was wondering what could cause the Orig Cause Location 2 and 47.

Any help would be much appreciated. Thanks!

Pascal

[Amine Nouasri]

Code 47 means CM is unable to allocate a resource. It could a DSP, codec issue, media resources allocation. If you can post some debugs regarding a failed call. We can maybe point you out in the right direction.

debug voip ccapi inout

debug mgcp packet

Please rate helpful answers!

[Pascal Douce]

Hi Amine.

Thanks for your reply.

Since we can't reproduce the issue whenever we want, is it safe to launch the above debug commands continously on the Router ?

If this is OK, we will setup it up until the issue is reported again. We can setup a syslog server to gather the logs.

Pascal

[Jorge Armijo]

Pascal,

Yes, you can setup a syslogg server and enable the debugs, you can leave the logging for a long time without affecting the gateway performance.

In addition, you'll need to enable CCM traces:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a0080094e89.shtml

HTH

--
Jorge Armijo

Please remember to rate helpful responses and identify helpful or correct answers.

[Pascal Douce]

Hi Amine and Jorge,

Thanks for your reply.

Let me setup the syslog server and CCM traces and I will update this post with the debug outputs when issue is reported again.

BR

Pascal

[Pascal Douce]

Hi All,

The issue was reported again this morning.

Here's what i've observed on CDR:

Time of call : 10:03:15

Calling Party : 46427XX

Called Party : 40691XX

Originated Cause Value : 16

Originated Cause Location : 2

Destination Cause Value : 0

Destination Cause Location : 0

It seems that the issue is coming from PSTN with cause code 2. This code means "no route to specified transit network(national use)"

I managed to get the output for debugs mentioned.

Grateful if any can help out.

Thanks

Pascal

[Nishant Savalia]

Hi Pascal,

Log shows that gateway has received MDCX from CUCM stating M = recvonly.

For further analysis, detailed RTMT trace is required along with debug isdn q931.

Please see if it's possible to manage.

Also, call drops only in case of incoming or outgoing also? It happens with particular dn or every dn of 7962 phones?

Regards,

Nishant Savalia

[Pascal Douce]

Hi Nishant,

Thanks for your reply.

I have enabled debug isdn q931 on the gateway. I will work on the CCM traces and make them available when issue occurs again.

Ques :Also, call drops only in case of incoming or outgoing also?

Ans : Well it seems that this issue is occuring for incoming calls

Ques : It happens with particular dn or every dn of 7962 phones?

Ans : For now only one 7962 G has been deployed for admin and a few 6921 phones for guests. No complains have been received from guest side.

I've managed to get the following traces for the above call

2013/09/23   10:03:15.666|CC|SETUP|48633197|48633198|46427XX|40691XX|40691XX

2013/09/23   10:03:15.668|CC|OFFERED|48633197|48633198|46427XX|40691XX|40691XX|S0/SU0/DS1-0@LBM-MCC2-GW2901-01.lbm.local|SEP203A07FD8359

2013/09/23   10:05:22.518|CC|RELEASE|48633197|48633198|16 I have one more question. On the Trace Filter Settings, should i tick all options or are the one selected(See attached) ok?

Thanks and Regards,

Pascal