Using CCM 188.8.131.520-3
MOH is configured using multicast and working fine internally, but not working externally.
MOH server is set to increment on IP and have increased max hops from 2 to 4.
Music is fine internally but not externally just get silence.
Any input would be appreciated.
Under the GW port configuration i.e. PRI in CallManager you need to apply the MRGL under Media Resrouce Group List, and then reset the GW.
Also, add "ccm-manager music-on-hold" on the GW.