CM Clustering

[Bishay Bishesh]

Scenario: distributed architecture with CM clusters at main site A and two remote sites B & C.

Question: if CM cluster at remote site C goes down, can the phones at site C register themselves to CM cluster at site B?

[Manish Gogna]

Are you talking about each site having a different cucm server or a cucm cluster? In case of each site having different cucm server, the phones can still register to a server ( of the same cucm cluster ) on a different site according to the Callmanager group settings in the device pool. You can read CUCM SRND to get a better understanding of the deployment models and redundancy feature.

HTH

Manish

[Bishay Bishesh]

hi Manish,

I am referring to the 3rd option in the attached file. It's the cluster at all sites.

Btw, i should also ask, what's the benefit of having cluster at remote site when SRST can do the same?

[Manish Gogna · Accepted solution]

Hi Bishay,

The pic you are referring to is actually for a single cluster. The three different callmanagers on the different sites are all part of the same cucm cluster, they are not three different cucm clusters. You can use SRST on remote sites as well but SRST has its limitations in terms of capacity and features when compared to CUCM server.

HTH

Manish

[Bishay Bishesh]

Hi Manish,

So when you say that they are part of same CUCM cluster, do you mean the remote sites only have the 'subscriber' and No 'publisher'.

How did you identify that they are part of same cucm cluster?

[Manish Gogna]

Hi Bishay,

do you mean the remote sites only have the 'subscriber' and No 'publisher'.

>> Yes

How did you identify that they are part of same cucm cluster?

>> If you read the Deployment Models section in SRND, it will be clear from there.

HTH

Manish

[Bishay Bishesh]

And, I have been reading the SRND 10.5 all day but couldn't get my clarifications.

[Terry Cheema]

If these are different clusters No. There is no way a phone can register with any server outside of its cluster.

If you mean All the Servers at Site A, B & C belong to same cluster then Yes its possible.

If its a same cluster, CUCM Group for Site C, has Site B Call Manager listed after Server C, then if the server at C goes down phones will register to Server B.

-Terry

Please rate all helpful posts

[Bishay Bishesh]

Hi Terry,

I was referring to different clusters. Got your point that phones can't register outside the cluster.

Is my below understanding correct:

you can do clustering in two ways- 

1) The remote site only has the Subscriber. This way it's only one cluster.

2) The remote site has both publisher and subscriber. This way there are independent clusters at each site.

Thus in #1, you can have phones of any site registering to any subscriber if configurations are done accordingly.

However, in #2, phones will not register outside their cluster.

[Terry Cheema · Accepted solution]

Yes correct.

Clustering is a feature to provide distributed call processing and providing HA and redundancy. In a cluster there can only be one Publisher and upto 8 call processing servers.

Please rate all helpful posts.

-Terry

[Terry Cheema]

Bishay - thanks for the rating. Please let us know if you have got any further queries, otherwise please mark the thread as answered.

-Terry