clustering over wan.

[sarahr202]

ipphones--ipnetwork-CM(sub1)-ipnetwotk---WAn--ipnetwork-(sub2)CM-ip network--Ip phones.
  Remote site1)|                                                             |   Remote site 2)          |
               |(tftp server1)                                                  |                           |( tftp server 2)
                                                                                   |
                                                                                  CM( publisher)
                                                                                  |
                                                                              ipnetwork
                  
                    

1) does subscriber1 i.e sub1 at remote site 1 provides call processing to all the phones in remote site 1?
2) If for some reason, ip phones at remote site 1 can not register with subcriber1 i.e sub1 at remote site, will they try to register with next available Call manager in their list they recive from tftp server 1?

thanks and have a great weekend.         

[clileikis · Accepted solution]

Hi there,

If you configure your call manager group (which gets applied to your device pool) to prioritize your sub at the remote site those phones will register to the sub and you can have your pub as a backup. Same for TFTP (which gets assigned via DHCP)

HTH,

Chris

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[sarahr202]

Thanks Chris.

I am just trying to get a basic idea as to how clustering works.

you can have your pub as a backup. Same for TFTP (which gets assigned via DHCP)

Can we also configure some other sub as our back up that is if we dont want pub to be back up ?

thanks and have a great weekend.

[clileikis · Accepted solution]

Hi there,

Yes absolutely, I assumed this was a 2 node cluster with a pub and sub (also assumed the call manager service was active on the pub). You can prioritize any servers in your call manager group that has the call manager service active (ex. Sub1/Sub2).

HTH,

Chris

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[allan.thomas · Accepted solution]

Hi Sarah,

Just a further to note to distributed clusters is that you don't overlook the WAN considerations, specifically around bandwidth for voice and signalling utilising Regions for codec capabilities and Call-Admission-Control, not to mention provisioning for replication between hosts. With that in mind you need to ensure that your carrier has implemented QoS based on your requirements, which is typically at an additional premium.

Regards
Allan.

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[Aaron Harrison · Accepted solution]

Hi

Basically it depends on your config.

You assign phones to a 'Device Pool'. One of the properties of a device pool is the 'CallManager Group' which is a list of CUCMs to use for service.

Your phones download this list as part of the TFTP configuration file for the phone.

So - if you have two subscribers, then yes, you would typically assign both to the phones' CUCM group, with the 'local' (or most local) subscriber highest in the list. The phones would then register to the local sub, and fail to the next one if that is not available.

Regards

Aaron