CM Clustering through WAN

[f-vanryckeghem]

Hi,

We all know that we can do a cluster of Call Managers on a LAN. Now, is it possible to do the same through the WAN.

In fact, there are only updates between the subscriber DB and the publisher DB. It should not take 100Mpbs of bandwidth.

Does anybody have any experience with that ?

Is that supported, because at the network & configuration level, nothing prevent us to do that ...

Thanks

Frederic

[gary.shaw]

Yes we've done it.

We put in the first "Cluster over a WAN" implementation. Im not sure that its officially supported until the end of January though.

You have to stick to the guidelines (when they come out) but it works fine in our scenario.

We are using 2 * 8MB HSSI links between the two sites using QoS over the link.

[rlyons]

In some documentation Cisco maintains that you should have at least a 10Mbps link between CallManagers in the same cluster. This rule was probably made to be excessively conservative (not a bad thing).

You should also keep in mind that there are two types of data other than SQL database data shared by CallManagers in a cluster, LDAP (DC Directory) and runtime data (CallManager-to-CallManager over SDL). A remotely located CallManager that is part of the local cluster might generate respectable amount of traffic if it had 2500 registered and relatively busy phones

Regards,

Bob