CME integrated into CUCM...

peanutnoggin

Hi TE,

I'm a VoIP noob so I'm quite curious... Can a router running CME somehow get integrated into a CUCM at another location? These locations are geographically separated and they do have a VPN tunnel between the two locations. Is it common practice to have a CUCM in one location and VoIP phones register to that CUCM from the remote site? Or is it a better idea to have the router running the CME register the VoIP phones and somehow integrate the CME into the CUCM? All questions, concerns, and comments are welcomed... Thanks!


-Peanut

broc

Both are possible actually but what you would normally do is setting up the CUCM at the main site and configure the router as a SRST device, not quite the full CME but enough to be able to deal with the voice internally in case the WAN link goes down.

Then, depending on the situation, you could also set up the router as a PSTN gateway for backup.

You can also "integrate" the CME router and set up a SIP trunk to communicate between the two sites if the IT/Voice departments are not centralised somehow.

Either way, you will have to get some sort of VPN between the sites.

pitviper

Yes, it's common to have remote phones register with a centralized call manager over the WAN - The branch office router would be setup to use Survivable Remote Site Telephony (SRST) so that it can take over call processing in the event that communications with the centralized "brain" is severed.

Or you can simply setup a trunk between the CUCM cluster and CUCME and setup the dial plans to send internal calls between the 2 isolated systems.

How good is your VPN connection? You'll have to take into consideration encryption overhead and QoS over the VPN link (either way that you go). Unfortunately you are at the mercy of the Internet once the traffic leaves your site. We have several sites where we hang IP phones off off 800 series routers over a VPN tunnel and for the most part, they work fine.

pitviper

broc beat me to it

peanutnoggin

Thank you both for your input. Right now I'm learning the voice world, but this is sort of our situation at work. It is not a pressing issue as our main site has not fully (nor will they anytime soon) implement their voice solution. We do have a 3745 (and spares in a test lab environment) that's capable of running CME. I knew this was possible, but I wasn't sure of the best implementation... now this gives me a realistic goal/project to work towards. I'll continue to study and learn the VoIP technology and maybe somewhere down the line, present the idea to the bosses and see what they say... who knows where this will lead. Thanks again!

-Peanut