Call Manager Backup Fails

[luis.veraza]

Hi,

Actually we have this connection:

IP Phones - CCMP(CCMB) - Router - PBX - PSTN

The problem is when the CCM Primary is down, the ip phones register with CCM Backup, but it(CCMB) does not register with the router with SCCP Protocol, the routers is working with CCMP, so, we can make calls to PSTN, Extensions, etc.

transcoder fails.

Do you know something about it ?

Best regards, Luis.

[jaregalado]

Hi, Luis,

What is the gateway hardware you're using (2600, 3600, VG200, etc) and the voice protocols used ?

H.323 IOS gateways don't register itself with the CCM like IP phones do, they just point their dial-peers towards the CCM, so I understand you can't get calls from the PSTN when the Primary CCM fails, is that correct ?

If that is the case you can configure redundant POTS dial-peers for each CCM in your voice gateway, then you'll be able to receive calls from the PSTN when Primary CCM fails.

Regards.

[luis.veraza]

Hi, Jaregalado,

The gateway hardware that we are using is 3660 and we use H.323 Protocol.

OK, That is correct, when Primary CCM fails, backup can´t make or receive calls to or from PSTN.

Sccp has only one Call Manager registered. the Primary. can i add the backup ?

best regards, Luis.

[thisisshanky]

Luis,

Like said in the other post, if its a H323 gateway, you will need two dial-peers with different preferences, so that in case of a server failure the gateway will send calls to the backup server.

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_configuration_example09186a0080094852.shtml

[maharris]

For the transcoding resource to register with the backup CM you want to do this:

Enable SCCP Gateway Mode

Perform these tasks in order to enable the Skinny Client Control Protocol (SCCP) protocol and its related applications (transcoding and conferencing).

Gateway#configure terminal

Gateway(config)#sccp

Gateway(config)#sccp local FastEthernet 0/0

Gateway(config)#sccp ccm 10.82.84.144 priority 1

Issue these commands in order to configure a connection to a second Cisco CallManager.

Gateway(config)#sccp ccm 10.82.84.145 priority 2

Gateway(config)#sccp switchback timeout guard 180

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_configuration_example09186a0080334294.shtml

For call processing, you need to follow the advice above, about the two dial peers, and make sure you follow the part about putting in the voice-class to set the timeout.

Mary Beth

[allan.thomas]

One further point to mention concerning the sccp ccm command, and that is to ensure that you have configured or specified the version of CallManager.

Previously, I have discovered that with IOS 12.3, the default ccm version is 3.1, which is not always the case.

Specify the full command as follows:

sccp ccm priority 1 version

For example:

sccp ccm 192.168.0.1 priority 1 version 4.1

Once you have specified your ccm version check whether the dspfarm has registered.

Hope this helps.

Allan.

[luis.veraza]

Hi, thisisshanky / maharris / allan,

Thanks !!, It helps a lot, Today, i´ll be doing some test.

I´ll keep you posted.

Best regards, Luis.