Impact of Call Manager Service Restart

[gpsriramdc]

Hi All,

We have planned to restart the Cisco Call Manager Service in the Cluster. While we restart the call manager service IP Phone to IP Phone Calls & MGCP Calls will be preserved .

What happen to the call in the below scneario's

1) Active Calls via SIP Trunk

2) Calls where media resources used ( MTP , conference , XCode)

3) Calls are in the process

4) Calls setuped by Route List , Hunt List

[Ayodeji Okanlawon]

Generally active calls are not affected because RTP streams do not terminate on CUCM except in some cases..

1. Active calls via SIP trunk are not and should not be affected. SIP is used for signalling and not involved in actual RTP streaming. However midcall/supplementary features such as call hold, transfer may not work as this require the intervention of CUCM.

2. All media resources registered to the CUCM will de-register while it is restarting. I believe active calls will stay up but any new call setup will be dropped

3. Calls in progress are likely to drop because this is still the signalling stage.

4. Route list/Hunt list dont setup calls. CUCM does. Calls are passed through these components. So this will be affected depending on whether calls are in progress or already completed

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[gpsriramdc]

Hi aokanlawon,

Thanks for swift Reply. In serviceability guide stated that 

"Unified CM and Unified CM BE only: Stopping a service also stops call processing for all devices that the service controls. When a service is stopped, calls from an IP phone to another IP phone stay up; calls in progress from an IP phone to a Media Gateway Control Protocol (MGCP) gateway also stay up, and other types of calls get dropped."

Has there any document is available to brief the impact of other call types such as SIP .

Thanks in Advance...

[Ayodeji Okanlawon]

I am not aware of any document that explicitly talks about sip. You have to treat sip as a signalling protocol. All signalling is handled by CUCM, while a call is in progress or supplementary features are invoked. When that CUCM goes down all signalling its handling drops.

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[Florian Zahn]

Hi,

to your initial statement: MGCP-calls are not preserved, because L3 is backhauled to the CUCM. So all active calls are dropped a few seconds after outage of CUCM-connection. Only in case of failover t a secondary CUCM the calls are afaik not dropped....

Regards

Florian