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New Member

Callmanager Redundancy and TFTP

In a Callmanager redundant environment, how do the IP Phones load when the publisher/primary/TFTP server goes down? As soon as I simulated a downed primary server, the IP phone restarted and would not load. I know the subscriber should be a backup, but I have found little to no information pertaining to a redundant TFTP server-only co-existing or dedicated.




Re: Callmanager Redundancy and TFTP

Please check the Call Manager Group configuration under System menu. It should have both the CMs listed. And this Call Manager Group should be listed under the Device Pool to which the IP Phones belong. In that case, when the primary(should be the subscriber) CM goes down, the phones will directly rehome to the secondary (should be the publisher which has the Tftp server also) without restarting.

In your case, the phones are not rehoming to the secondary means please check if the CallManager Group is correctly configured. The phone neednot contact the Tftp server again when the primary CM becomes unavailable, the phone already has this information who its secondary CM is, in it, when the phone first downloaded its configuration file from tftp server upon power-up or reset.

Also, you donot need a redundant tftp server, cuz the phones or other devices contact the tftp server only upon power-up or reset, and not when a CM in a redundant group goes down.

New Member

Re: Callmanager Redundancy and TFTP

What CallManager version are you working with for this scenario? I know that in 3.2, there is a field in the network settings on the 7960 that contains the address of a secondary TFTP server. You have to have the DHCP scope pass addresses for the primary and secondary TFTP to the phones. I have not had time to test this myself, and do not know when the support for redundant TFTP was added to CM and the phone firmware, but I will check. A call to TAC would get the quickest answer to this issue (when support was added.)



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