CallManager and VLANS!

[brian-henry]

Is there a document on stating what is the maximum networks that your CCM cluster can be broken down into? I mean is it ok to have a cluster that each server resides in its own network even though it sits in the same campus environment? Is is best practice to put all the CCM's in one network, because the SRND says "Typically, Cisco CallManager cluster servers, including media resource servers, reside in a data center or server farm environment. In addition, centralized gateways and centralized hardware media resources such as conference bridges, DSP or transcoder farms, and media termination points are located in the data center or server farm. Because these servers and resources are critical to voice networks, Cisco recommends distributing all Cisco CallManager cluster servers, centralized voice gateways, and centralized hardware resources between multiple physical switches and, if possible, multiple physical locations within the campus. This distribution of resources ensures that, given a hardware failure (such as a switch or switch line card failure), at least some servers in the cluster will still be available to provide telephony services. In addition, some gateways and hardware resources will still be available to provide access to the PSTN and to provide auxiliary services. Besides being physically distributed, these servers, gateways, and hardware resources should be distributed among separate VLANs or subnets so that, if a broadcast storm or denial of service attack occurs on a particular VLAN, not all voice connectivity and services will be disrupted"

Brian

[JOSE TORRES]

Your question can have multiple answers depending on how you want to distribute your callmanagers,

Do you want to provide 1:1 redundancy or 2:1 redundancy?

Also do you plan on providing local redundancy to where existing servers exist or remote where callmanagers will be spread throughout the campus?

Technically you can put callmanager servers all over the campus with up to 8 callmanager servers throughout your campus and one acting as the publisher (4.1 SRND).

If you look at the Clustering over the IP WAN section, what you need to ensure you provision is adequate bandwidth and a minimum delay.

If each server will be placed in a separate network, you have to ensure you can provide 1.544 mbps between callmanagers and no less than 40ms round trip time between each server.

[brian-henry]

Thanks for your answer but I know most of what you had mentioned above, especially where you can only breakup your cluster to only "3" over a WAN environment.

I was just wondering if there was any reason against putting each CCM in its own network so you can thru either VALCS or ACLS with no firewall protect what talks to each one. All the servers would be sitting in "1" location in a Centrailzed Call Processing Model.

I know about the round trip times,etc.. I was just thinking also about if a DoS attacck or a network attack from a virus or worm infected "1" server it would be contained within that network because that would be the only one in that VLAN and if you control what ports can go in and out of that VLAN then the affect would be minimal.

Thanks again.

Brian