MoH via CUCM (multicast)

[spencermoore]

I'm attempting to configure my 2900 series router (voice gateway) to "tune into" my MoH multicast stream generated by the CUCM server. When callers are placed on hold they hear nothing but silence. When testing I am able to see results in the "show ccm-manager music-on-hold" output, but don't get any additional info from debug commands. Internal calls MoH are working without issue. Topology is as follows: Gateway (2900) --> Switch (L2) --> CUCM. What I've done thus far:

* Verified CUCM configuration (confirmed by Cisco TAC)

*Enabled multicast routing on gateway.

*Enabled multicast and igmp snooping on switch between CUCM and Gateway

*Enabled "ip pim sparse-mode" on interface facing CUCM on Gateway

*Issues "ip igmp join-group x.x.x.x" command under CUCM interface

*Added "ip pim rp-address x.x.x.x" command pointing toward CUCM. 

*Added "ccm-manager music-on-hold" command on Gateway.

Thanks for your time!

[Chris Deren]

If the GW is local to the CUCM why are you using it to provide MMOH?  This approach is normally used at remote location where multicast traffic cannot be delivered i.e. MPLS.  Why not simply allow CUCM to play the MMOH to the local devices (phones, GW, etc)?

[spencermoore]

Not entirely sure what you are asking. CUCM is playing MoH via Multicast. I need the Gateway to receive it so PSTN callers hear the music. 

[Chris Deren]

I assumed you want to stream MOH from the GW as that is doable, but if you only want it to receive the stream then there is nothing you need to do on the GW for that.

Does it work between phones?

Is the voice GW on the same VLAN as the servers?

If not does it work with pim-dense mode instead of pin-sparse as this would not require rendezvous points? (however sparse is recommended)

Do you have proper MRGL assigned to the GW on the device pool used by the GW in CUCM?

[spencermoore]

Yes, gateway needs to receive not generate the stream. Internal (between phones) is working without issue. Yes, the GW is on the same subnet as CUCM. I've also tried dense-mode to no avail. As far as I know, all CUCM configuration is correct. I've worked with TAC on this and it seems all CUCM is good-to-go.

[Chris Deren]

if GW is on the same subnet as CUCM server then this is not multicast routing issue.  Here is what I would suggest:

compare the device pool and MRGL/MRG used by the phones to the one used by the GW, if you can temporally apply the phone DP/MRGL to the GW and test. 

Are you defined to use G711 codec between the GW and the phones?

[spencermoore]

It appears the phones are in a particular device pool, but none of the gateways have a device pool configured. Should the GW in question reside in the same device pool as the phones? Pardon my ignorance, I'm a voice newbie. I appreciate your help!

[Chris Deren]

There needs to be a DP assigned to GW, it i a required field.  It depends on whether you use the same one as the phone, all based on the parameters you want to use, but for the most part it is acceptable.

[spencermoore]

Actually, on further inspection it looks like the GW is in another device pool. Not the same as pool as the phones, but it is in one.

[Chris Deren]

You need to reset the GW after changing the DP, so I would advise to do this after-hours.  Make sure you compare the settings of current DP to the one you are changing as that may have impact on things.  

GWs have to have DP applied, so how do you see there is not one assigned? Can you post a screen shot?

[spencermoore]

It was actually applied to a device pool, I just had to drill down into the GW menu to see it. It didn't show on the "Gateway" page under "Device". 

[Chris Deren]

OK, so is it the same DP as phones are using? 

If not, does that DP have proper MRGL applied, or is there an MRGL applied on the GW itself?

The issue comes back to 2 things, one incorrect MRGL is used not having access to proper MOH server, 2: codec issue between the MOH Server and the GW itself driven by the region setting between the 2 device pools. If G729 is used for example that needs to be enabled in service parameters as it is not allowed for MOH by default.

[spencermoore]

The GW is in a separate DP. It appears both DP's (phones and GW) have the same MRGL configured which has access to the MRG which has access to our MOH media. This seems really convoluted to me, but I think the config checks out..

[Chris Deren]

How about the Regions assigned to these individual DPs? Are they using common region or different ones? If different ones what is the codec configured between the 2 regions?

[spencermoore]

They are the same...