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New Member

Integrating 2 CME's in the same LAN

Is it possible to have 2 CMEs with CUEs in the same LAN to work together?

I would like to get 2 CMEs to work together in the same LAN. My objective is to have CUE voicemail for 300 users by having 2 separate routers with CME and CUE to share the phones.

50% of the phones on one CME and the rest on the other. Or is there a solution where in we can have both the CMEs to handle all the Call management?

Please suggest some ideas. Thanks a lot.


Re: Integrating 2 CME's in the same LAN

You could create voip dial peers to integrate the CMEs and use VPIM to network CUE. I think the administration in this scenario would get complicated very fast especially if you anticipate any growth. With this number of users, I would suggest taking a hard look at the benefits of moving to Callmanager and Unity.

Hope this helps. If so, please rate the post.


New Member

Re: Integrating 2 CME's in the same LAN

Thanks Brandon.

The integeration of 2 CMEs is getting more and more complicated as I delve more into it. So,Call Manager seems a likely solution for me.


Re: Integrating 2 CME's in the same LAN

Your main issue is going to be DHCP. Is using two vlans with two subnets an option? Mainly CME devices are going to talk to the CME based off the TFTP server given to them. Setup two vlans with L3 interfaces with different helper addresses pointing to two different dhcp servers, 1 CME reference per L3 interface. Each DHCP server would have a different TFTP server. You need to understand if they move there phone around though to a different VLAN they won't get connected to the correct CME and thus not register. Configure the CMEs with h323 or sip trunks to allow them to talk to each other. Make sure that you give each CME a different extension range, example 1100 for CME 1 1200 for CME 2. The dial peers would route between with 11.. or 12..

So the quick answer is it can be done, it wont be clean though.

Additionaly are you saying that each CME would have a CUE? If you are trying to share a CUE, I have never setup a CUE that was used externally but it might be able to be done.

New Member

Re: Integrating 2 CME's in the same LAN

Thanks Fred. Your answer clears many of my doubts, but the complexity has cast doubts on using 2 CMEs. Also it seems like there will be more problems involved with IVR integeration with 2 CMEs. Hence, I think I'll go with Call Manager solution.

Re: Integrating 2 CME's in the same LAN

Wow, 300 users on a Key System (albeit a nice key system). I think sometimes Cisco does too good a job marketing its solutions. In the TDM days, nobody - even management composed of accountants, would've entertained such a solution.

A few design problems:

There's no economy of scale. What will you do when you grow to 350 people?

CUE wasn't built to do this kind of "clustering." Is availability important?

You'll need to either 1) double your circuit count or 2) double inbound/DID PSTN circuit count and mesh outbound dial-plans. Potentially Ugly and Painful to maintain.

Finally, if a CME fails, half your user-base is without a phone.

Seriously, as Brandon suggested, look at CallManager and Unity as a much better fit.

Good luck,


New Member

Re: Integrating 2 CME's in the same LAN

Thanks Michael, for the reply.

This is one of the rare cases where the company is going to gradually go down in size and hence the numbers are going to decrease.

As u said, it looks very complicated and hence I will be looking at a Call Manager solution.


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