Phone call during a cucm failover

[rramlal]

Hi All,

I have to test failover of a cucm cluster. Can you advise what should happen when a phone call is in progress and the call manager that the phone is registered to fails? Will the call still be up?I want to know what to expect in the failures.

Thanks

[yahsiel2004]

The call will remain up but once the call has ended the phones will register with their secondary CUCM server.

HTH

Regards,

Yosh

[Chris Deren]

It depends on what trunk the call is connected to and voip protocol in use.  Internal calls between phones will stay up as will H323/SIP calls over PRI/etc with message that features (hold, transfer, etc) are down.  MGCP call over PRI for example will disconnect as the D-channel will go down due to it being backhauled to CUCM.

HTH,

Chris

[Gordon Ross · Accepted solution]

Chris Deren wrote:

MGCP call over PRI for example will disconnect as the D-channel will go down due to it being backhauled to CUCM.

Are you sure about that...?

GTG

[Chris Deren]

Thinking about it, it might be preserved, but I have not worked with MGCP in years so that's my excuse :-)

Chris

[yahsiel2004]

Good stuff Chris and Gordon (+5)

Regards,

Yosh

[Gordon Ross]

If the media is not going via the server (e.g. via an MTP, Music on hold, etc) then the call will continue without interruption.

Once the call completes, the phone will reset as it re-registers to the backup subscriber.

GTG

Please rate all helpful posts.

[Rob Huffman · Accepted solution]

Hi there,

+5 to all my friends here Gordon, Yosh & Chris. You are

too fast for my useless skills

I thought this was pretty good;

Table 11-1 Call Preservation Scenarios 

Scenario	Call Preservation Handling
Cisco Unified Communications Manager fails.	A Cisco Unified  Communications Manager failure causes the call-processing function for  all calls that were set up through the failed Cisco Unified  Communications Manager to be lost. The affected devices recognize that their current Cisco Unified  Communications Manager failed. Similarly, the other Cisco Unified  Communications Managers in the cluster detect the Cisco Unified  Communications Manager failure. Cisco Unified Communications Manager maintains affected active calls  until the end user hangs up or until the devices can determine that the  media connection has been released. Users cannot invoke any  call-processing features for calls that are maintained as a result of  this failure.
Communication failure occurs between Cisco Unified Communications Manager and device.	When  communication fails between a device and the Cisco Unified  Communications Manager that controls it, the device recognizes the  failure and maintains active connections. The Cisco Unified  Communications Manager recognizes the communication failure and clears  call-processing entities that are associated with calls in the device  where communication was lost. The Cisco Unified Communications Managers still maintain control of the  surviving devices that are associated with the affected calls. Cisco  Unified Communications Manager maintains affected active calls until the  end user hangs up or until the devices can determine that the media  connection has been released. Users cannot invoke any call-processing  features for calls that are maintained as a result of this failure.
Device failure (Phone, gateway, conference bridge, transcoder, MTP)	When a device  fails, the connections that exist through the device stop streaming  media. The active Cisco Unified Communications Manager recognizes the  device failure and clears call-processing entities that are associated  with calls in the failed device. The Cisco Unified Communications Managers maintain control of the  surviving devices that are associated with the affected calls. Cisco  Unified Communications Manager maintains the active connections (calls)  that are associated with the surviving devices until the surviving end  users hang up or until the surviving devices can determine that the  media connection has been released.

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/8_0_1/ccmsys/accm-801-cm/a02dvsup.html#wp1021885

Cheers!

Rob

[Gordon Ross]

rob.huffman wrote:

+5 to all my friends here  Gordon, Yosh & Chris. You are
too fast for my useless skills 

We only gave one-line answers. You RTFMd and gave the full details!

GTG

[Chris Deren]

+5 Rob and Gordon for correct answers and setting me straight.

Chris

[yahsiel2004]

Seriously, you always go above and beyond Rob (+5)

Regards,

Yosh

[rramlal]

Thanks to all for their swift responses. +5 to all