CUCM Intracluster dialling using Gatekeeper

Unanswered Question
Sep 19th, 2008


Have an questions about using a gatekeeper for routing between dial plans on the same CUCM cluster.

I have come across an issue where the dial plan is very poor and as such we have overlapping dial plans. I have a couple of questions. Can a gatekeeper be used for intracluster routing, my understanding of the gatekeeper is that it routes intercluster dial plans and therr should only be one CUCM cluster per zone.

For example I have extension 1000 at site A and extension 1000 at site B (Can I just add this is not my design, I would not have done it this way)both on the same CallManager cluster. There is a site A partition for the A Phone and a B partition for the B phone. So if Site B ext 1000 calls site A 1000 then they would in turn add a prefix (say 554), this prefix then gets stripped off on the site A side and rings 1000, the call details then show 5551000 as the recieved call so when A calls B back it dials 5551000.

Is theis best to do this using a gatekeeper or using callmanager in a multitennant fashion. If I use the latter what effect will this have on Unity I would need to make this multitennant support also.

At the moment 1 site (the main and CUCM location)has 4 digit dial plan the other three much smaller sites have a 7 digit dial plan. (The idea is to have all sites 4 digits with intersite prefix)but want to see if I can do this on a gatekeeper or would it be best on the CUCM

If I had the chance to rediesign I would but its live and trying to tidy it up.

cheers once again


I have this problem too.
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Marwan ALshawi Fri, 09/19/2008 - 01:40

hi Paul

from my understanding from the above post, it sounds u have dial-plan and numbering issue

and gatekeep is not required for two reasons

firs it will not be responsible of numbering translation

secondly gatekeeper reponsible for CAC mainly if u have bandwidth limitations or policies then Gatekeeper ur choice,BUT in ur case wont work as well !! because i can see u have one CUCM.. while u need at least two CUCMs or CUCM with CME to make the gatekeeper make CAC if u look for CAC with on CUCM cluster then go to regions and locations way!!

and from ur description it is not good idea to make both site overlap

but as long as there is site prefix like 554 then its ok works fine

and with unity u need to rigister the phones with the site extention

if u have problem sending the site extention to unity make translation pattren

i havnt done it this way but try

for example lets say ur voice mail number is


make translation pattren match 1234

and prefix to the calling number 554 for site one and 555 for site two

and make sur eu creat two transaltion pattren one for site A with partion only site A have access to and prefix 554

and another one for B with partion only B have access to and prefix 555

and for both translation pattrens make sure they have CSS that access the voice mail port partion

in unity phone 1000 site A should be 5541000

so when phone 1000 press the VM butten this butten assiciated VM profile that dial the VM pilot number in our example we said 1234

then will match the created translation pattren that A have access to and the calling number will be translated to 5541000 so wil match the number i unity

the same idea for B

good luck

if helpful Rate

bigcappa1 Fri, 09/19/2008 - 01:48


Thanks for that you confirmed what I understood that a gatekeeper will not resolve the issue here. Gatekeepers dont translate overlapping dial plans on the same cluster. Ok I understand about the VM as well so that should be simple enough, just need to think about it. thanks very much for the good advice



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