CCM Cluster across WAN-How much BW is enough?

[gbrome]

My company is thinking about installing 4 Call Managers in one cluster, two CCMs on the U.S. East Coast, two CCms on the West Coast. I am aware of the 40 ms max RTT time requirement. How much BW do I need for a company of approximately 3000 users, split between coasts. We were thinking about separate clusters, but having one gives us a common directory without having to us AD and provides more redundancy between coasts. Does anyone have any real-life implementation experience with this, or a good estimate? Thanks!

[rnarayana]

Hello,

If you look at the design guide it will give you a good idea .

Below is the link.

cisco.com/go/srnd and look for the design guide.

Thanks,

Radhika

[gbrome]

I see what you mean. The theoretical maximum is 1860 miles. The distance between my locations is more than that.. Mapquest says 2900 miles.

Thanks!

George

[jolo07310]

It's not about distance, its about round trips. If you can ping from one to another locations, less than 150ms (guessing, I forgot exact time), it will be fine.

[steve]

under 100ms delay 1 way good 200ms dont go higher.

[gbrome]

A call with Cisco engineers since posting my original message says prety much the same thing. Right now we are looking at a rtt of 96 ms, so I think we are going to give it a try. Thanks for the reponses!