Call Manager & Call Manager Express

[ITDreaming]

I have a question maybe you guys can help me out with. I installed call manager express to a few different branches and I'm configuring call manager at the central office. I am trying to figure out what do I/ would I/ or How do I configure the system that IF call manager for some reason goes down so that the call manager express on the local systems (the branch offices) kick in until call manager comes back up. i would appreciate any help or if you could point me in the right direction I would be really grateful.

 

[trvlr1]

The usual way to do this, if I am reading this right, is to use SRST enabled routers at the remote locations, so when the CM goes down, they reregister all the phones to the router instead of the CM.
In CME sites, all the brains are at the remote sites, it is a stand alone system, like a key system, not controlled by the CM, so the operation at the remote sites would not be affected by the CM going down.
The only other scenario I can infer from what you said, is that all calls go to the CM and are rerouted to the remote sites. In that case, you may have to start talking to the local telco to see if they have the ability to reroute calls in the event of an outage. This would require you to have lines sitting at each of the remote sites for them to transfer calls to. This would add recurring costs to your phone bill though and possibly the purchase of hardware to accept the lines too.
Hope this helps.

 

[ITDreaming]

trvlr,

Thank you for the input but from my understanding there is a way to use CME as SRST for fallback? the main office is used the central "hub" if you will and if the wan goes down we want the local cme box to take control so calls can still comein and out of the location

 

[trvlr1]

That may be true, but I am not familiar with that set up. You would still have to have some way of getting calls to go to the alternate location however it is done. Sorry I don't have any other info on that set up, maybe someone else here does .....

 

[ITDreaming]

trvlr1,


Thank you for your assistance, I appreciate it.

 

[whykap]

No actually it is not an option. The router can be configured as a standalone CME or an SRST site.

 

[ITDreaming]

Whykap,

So it cant be CME as SRST? Ive been looking online and ive come across a few places where it says it can be done.

 

[whykap]

No it cannot. SRST and CME is the same as far as licensing but it will not work together.
SRST stands for survivable remote site telephony meaning that a remote site that is connected to a centralized call manager will have basic functionality if it loses connectivity to the central site. That means that the local router with the proper config will take over for call manager and give users basic telephony functions.

CME is a standalone application and it is not a remote site not does call manager is aware of it. They can communicate but they are two different systems.

 

[ITDreaming]

Whykap,

Thank you very much for the information.