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Community Member

Gatekeeper implementation : who knows the gateways ?


I have several clusters of CCM in my network. I also have several VoIP sites (traditional telephony systems connected to the WAN via an IOS).

I also have several Gateways that are used depending on the cost of the routing !!!

Well, I want to put a gatekeeper in the middle of all this to simplify the routing on my CCMs and to manage inter cluster calls and off net calls. I want to have the CCM to go to the Gatekeeper eveytime the dialed number is not belonging to him.

My questions are the following:

1- Does the CCM know the Gateways or is it the Gatekeeper that tells the CCM what Gateway it should use depending on the dialed number ?

2- What should i configure on the Gateways for internal access? The CCM adresses or only the Gatekeeper ?

thanks in advance

Community Member

Re: Gatekeeper implementation : who knows the gateways ?

ANyone has an idea ?

thanks in advance

Community Member

Re: Gatekeeper implementation : who knows the gateways ?


You can create a GK controlled trunk on the ccm and point all outbound calls to the GK trunk instead of the actual H323 GW. In this case, the ccm would only know about the GK and not the H323 GW unless you specifically add the H323 GW in ccm.

For inbound calls to the ccm, the H323 GW would ras the GK and then the GK would tell the GW to send calls to the ccm. On the gatekeeper you would need to configure a callmananger zone that contains all the DID blocks for your company. Make sure that the GW and the GK controlled trunk register with the GK.

Hope this helps..


Community Member

Re: Gatekeeper implementation : who knows the gateways ?

Hello, those are great questions. Let me answer them in order:

1) After CCM 3.3, you defined one or more gatekeepers to the Call Mgr cluster, and then you defined trunks that use these gatekeepers. The trunk definition(s), if done properly, registers on the Gatekeeper and you can verify with a SHO GATEK END command. You will also register a prefix - the prefix is defined when you build the trunk configuration - on the Call Mgr. You can see the prefix registered with SHO GATEK GW-TYPE-PREFIX. This prefix can be used for call routing - or you can just dump calls off to a default-technology prefix. That's typically how Cisco recommends. I personally like to use the prefix in my dial plan.

In order to do admission control between your Call Mgr clusters, I believe you need to set up a zone for each cluster - and then define the bandwidth allowed between zones. You'll see this referred to in the SRND ( as Gatekeeper admission control.

2) I would configured the Gateways to also use the Gatekeeper. The gateways will register their E.164 (analog VIC ports) or a TECH-PREFIX (if you have digital VWIC ports) onto the gatekeeper. It makes it easy if the TECH-PREFIX is part of the dial-plan. Your VoIP peers on the IOS gateway will point to session target ras now instead of an IP address.

Since the Gatekeeper controls all of your dial-plan, it becomes a very critical component. So, get two of them! Both IOS gatekeepers and Call Mgr can register with two Gatekeepers.

The answers to your questions can get very deep! I have a single Call Mgr cluster and about 200 IOS VoIP gateways attached to Norstar key systems. I have two gatekeepers managing the dial plan. It works great.

Best of luck.

Community Member

Re: Gatekeeper implementation : who knows the gateways ?

Thanks a lot guys for your answers.

Kbyrd, nice to see it works great. My system should be very heterogeneous as I will have Alcatel PBXs, IOS gateways (with traditional PBX behind) and CCMs...Therefore, my Gatekeeper will be INDEED very critical.

What type of GK do you suggest?

Thanks again

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