Multi-Site CMEs - Advise/Recommendations Needed

[seanwy]

hi folks,

i've a client looking at deploying CME at 5 locations (Site A,B,C,D,E where A is the HQ), with each site sustaining around 10 employees. The sites wud be connected via a Hub(Site A) & Spokes (Sites B,C,D,E) topology, where each site sustains a 2MB leased line to the HQ.

I've browsed thru the ciscopress CME book and found tt they had recommended a TANDEM design, whereby the HQ CME will act as proxy for the various dial-peers for inter-site calls, rather than having all the dial-peers configured per CME site.

Any recommendations from folks who had successfully deployed multisite CME/CUE?

Thank you!

regards,

sean.

[thisisshanky]

I would suggest using a gatekeeper for dial plan resolution between remote sites. The hub site router can be the GK, as every site has only one link going to the remote and use PSTN as backup to call between the sites.

HTH

[seanwy]

Hi Shanky,

Thanks for the suggestion. I'm not exactly familiar with the concept of gatekeeper. So does it mean I need to get the gatekeeper license for the ISR router, and at the same time, it operates as bas a CME & a gatekeeper? Or do I need to get a gatekeeping appliance?

Thanks!

Sean.

[thisisshanky]

Gatekeeper concept is very easy to understand. Check this link.

http://www.cisco.com/en/US/tech/tk1077/technologies_tech_note09186a00800a8928.shtml

At the hub site you might have CME on a router. That router can act as the gatekeeper for your dialplan resolution. You define voip dialpeers at each remote site for inter office calls and rather than having different voip dial-peers pointing to each other for every other office you want to call, you just specify

session target ras under the each voip dial-peer. This will tell each remote branch router to consult with the GK as to how to reach the destination number. This reduces the configuration required on each remote branch router(adhoc) for calling each other.

You can even condense all your VOIP dial-peers required at each branch to just one dial-peer matching multiple branches and point it to RAS.

HTH

[agopala]

I dont think you should tandem calls. Either use a GK or if you do not expect to have too many inter-site calls, just send calls from remote router to the other remote router.

[NAVIN PARWAL]

I have a siliar situation, the only difference is that i have a centralized callmanager cluseter and 10 remote sites with ccme and unity express. Will i loose any fuctionililty if i put all the dialpeers at remote ccme sites to the central GK interms of call transfer, etc.

Thanks