MOH is working just fine internally, dn to dn. I've configured the DP to use the MRGL, this is the same DP the gateway uses, and even specified the MGRL in the gateway's config.
I've used the "ccm-manager music-on-hold bind FastEthernet0/0" on the gateway to bind it to the Ethernet port that connects to the CUCM's.
I've made sure the IPVMS has all codecs selected.
Using the "sho ccm music" on the gateway while i've got an external call connected to an internal phone, and on hold, I can see it's connected to the multicasing MOH server address.
Current active multicast sessions : 1
Multicast RTP port Packets Call Codec address
126.96.36.199 16384 0/0 206774 g711ulaw Fa0/0
I've tried removing the voice-class codec from the dial peer so the calls use g729 instead.
The externall caller here's nothing. and voice packets on the "show ccm music" never grow, they always stay zero. This makes me think it's a codec issue, but I'm out of ideas.