MRG/MRGL

[Ellen Kennedy]

                   So I've been doing Cisco voice for a few years now and I cannot seem to get the proper grasp on MRG's and MRGL's and how they should be configured with annunciators, CFBs, MTPs, transcoders, etc....

My question is, reagardless if I apply these MRGLs to the device pool or the devices itself, do SIP/SCCP phones need all of these items in the MRG contained in the MRGL? I guess what I am really asking is how should your resources be configured for devices throughout the CUCM system. I always configure the dsp resources in the routers with a transcoder and conference bridge at the least, and have those register to CUCM, but I'm having trouble getting a grasp on how they should be setup.. I know this depends on the use in each scenario and the number of users in each environment, but there has to be some scale that could be followed when deploying these systems.

[acampbell]

Ellen,

I know this tech note is getting a bit old but the principles are still the same.

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a008020f198.shtml

Hope this helps you

Regards,
Alex.
Please rate useful posts.

[Ayodeji Okanlawon]

Ellen,

The best practice with regards to resources in MRG are these

Conference Bridge

1. When you are using Hardware based conference bridge, do not assign both SW CFB and HW CFB in the same MRG. The reason is because CUCM assigns resources in the same MRG in a round robin fashion, hence when a device requests a CFB resource, CUCM does not make the dinstiction between what the device needs and whats available. This leads to scenarios where conferencing fails for conference calls with G729 should a SW CFB be assigned.

So always ensure you have SW MRG and associate SW CFB to them and then have HW MRG and associate HW MRG to them

2. Provision Media resources such as CFB and Transcoders on gateways local to the devices that needs them eg. Branch phones should use Media resources on branch gateway etc.

3. Transcoders and MTP.

Ensure you do not have MTP and transcoder is the same MRG. Assign xcoders to a different MRG and MTP to another MRG and ensure the MTP MRG is on top of the MRGL..

This is because When CM needs an MTP, it picks the first available MTP/Xcoder it find in the MRGL. It is not smart enough to know that if it needs a g729 MTP to pick a g729 MTP resource over a g711 resource. Hence, you should only have one codec-type MTP in the MRGL, for the codec that you intend to use across the trunk.

On Xcoder (except the Universal Transcoder).. Needs a G711 leg on side.. "G729 -- G729"

legs not permitted on an Xcoder.

In summary if you assign MTP and Xcoder to the same MRG and your MTP is a G729 MTP, then that device may be allocated for xcoding purposes and your xcoding request will fail.

4. Finally do not leave any media recource hanging. Ensure you have all un used media resource assigned to a MRG. Even if this MRG wont be associated to anything. This is good practice

5. Annunciators are used for announcement purposes. Ensure you have the right locales installed if you need them. There is not much to them.

Hope this helps

Please rate all useful posts

"'Nature is too thin a screen, the glory of the omnipresent God bursts through it everywhere"-Ralph Waldo Emerson

[Ellen Kennedy]

Thank you very much, thats great information.

Does the device pool selected when initially setting up a hardware conf bridge matter? How does this compare to a phone that is in the same device pool as the hardware conf bridge vs. the conf bridge in the MRG thats in the MRGL that is associated to the phone...

[Ayodeji Okanlawon]

Typically, I usually assign the device pool that the hardware CFB is in to the same CUCM servers that I use in the sccp configuration on the gateway. Thats all I think matters. If the phone is in a different device pool i dont think that matters.

The transcoder is what needs careful consideration when selecting the device pool. Basically you want to ensure that the xcoder is placed in a device pool such that the devices that needs it will use G711 to it. I.e the region setting is very important.

Please rate all useful posts

"'Nature is too thin a screen, the glory of the omnipresent God bursts through it everywhere"-Ralph Waldo Emerson