CUCM 10.5 not sending SIP BYE to CUBE when there is a phone failure

[Gianstefano Monni]

Dear all

We suspect that there is a misconfiguration on our voice gateway (CUBE) or on CUCM10.5

Basically this is what we experience:
1.       SCCP Phone calls an external number

2.      call is established, no problems
3.      The internal phone is shutted down (a script running on a remote switch shuts down all the ports)  and we see the call on the CUBE stays UP.  The user does not hang up the call, the phone is just powered off with the call still in place. 

Please note:

1. When a call goes through the ISDN Gateway and the phone is powered off, the call is terminated after more or less 1 minute

2. The SIP trunk going to the CUBE is configured to use MTP,

After a debug session on the CUBE we see that the CUCM doesn't send any SIP BYE when the phone is shutted down and it is not reachable anymore from the CUCM.

Is there any setting/timeout parameter that we should configure on the CUBE/CUCM to force the CUCM to terminate the call when the phone is not recheable anymore?

thanks for your help!!

stefano

[Mohammed al Baqari]

Hi,

SIP protocol has call preservation enabled by default and can't be disabled on CUCM or CUBE (unlike H323 or MGCP). However, you can enable media inactivity detection on CUBE to drop the call in case no media is detected.

Then you need to configure RTCP timers to control the silence time before dropping the call.

'This feature is controlled by two commands which are ip rtcp report interval global command and the timer receive-rtcp gateway-level command'

ip rtcp report interval 1000

gateway

media-inactivity-detection

timer receive-rtcp 5

This will allow 5 seconds of pure silence before dropping the call. Make sure that you disable VAD

[Gianstefano Monni]

hi Mohammed

thanks for your answer, i tried but it doesn't fix the issue.

moreover, the available command is different from you mentioned, i have only
(config-gateway)#media-inactivity-criteria ?
  all     Both RTP and RTCP for silence detection
  rtcp    Use RTCP for silence detection
  rtp     Use RTP stream for silence detection, this is default
  rtplib  Use RTP ( comfort noise = activity) for silence detection

and i have these timers:
"timer ?
  media-inactive  (dsp based) configure media inactivity timer- available for h323/sip only at this time
  receive-rtcp    (non-dsp based) configure media inactivity timer- available for h323/sip only at this time
  receive-rtp     configure absolute RTP receive timer in seconds

i tried some combinations but it does not work...

[Mohammed al Baqari]

Use the command 'media-inactivity-criteria rtcp' along with 'timer recieve-rtcp 5'. Also, make sure that your ip rtcp report interval is set to 1000.

[Mohammed al Baqari]

I just tested this config in my lab and got it working after 15 sec

ip rtcp report interval 1000

gateway
 media-inactivity-criteria rtcp
 timer receive-rtcp 15

[Gianstefano Monni]

Dear Mohammed,

i tested it but unfortunately using this setting the gateway drops ALL the calls that are longer than the receive-rtcp. Maybe the "silence detection" can be tweaked?

thanks

s

[Mohammed al Baqari]

You need to make sure that RTCP is enabled under your phones configuration window or common phone profile. FYI, phone settings override common phone profile.

[Gianstefano Monni]

hi mohammed, thanks for your message. i will test it tomorrow morning from my phone, but enabling it in production would require changing the Device pool of all endpoints (and restart them). We are also involving the support contract to check if there is a less invasive way to achieve the same goal because we noticed that even if the CDR from CUCM reports that the call ends, the CUCM is not sending any signal to the CUBE.

thank you

s

[Mohammed al Baqari]

In the fact the change needs to be applied on Common Phone Profile and will require phone reset as you mentioned. This needs to be scheduled activity.

Instead you can use media-inactivity-detection rtp instead of rtcp. Then tune rtp timer under the gateway instead of rtcp.

[Gianstefano Monni]

hi Mohammed,

thanks for your message. I tried these settings:

ip rtcp report interval 1000
gateway
 media-inactivity-criteria rtp
 timer receive-rtp 180

but the call stays UP. I tried with different timeouts, but the call is not shutted down.
We opened a case with Cisco TAC to investigate further.
Thank you,

stefano

[Gianstefano Monni]

Dear all,

we contacted Cisco TAC and we were able to fix the issue by applying these settings:

ip rtcp report interval 5000

gateway

media-inactivity-criteria all

timer receive-rtcp 6

we are not using RTCP and with these settings the "ghost" calls are dropped after 45 seconds. We are relying on the rtp monitoring and the default timer settings seems to be OK for our setup (tested with FAXes as well).

[Tristan Cober]

I've also seen this annoying behavior when an SX80 unregistered due to a camera problem in background and dropped the call, but CUCM didn't send a BYE to the Expressway so the call was stuck there and they could not redial due to only having 1 Traversal license.

If anyone finds a workaround to get CUCM to send a BYE, please post in it this thread.