phones 7921 doesn't hear IOS MOH multicast

[sdeltoro1]

I have cucm cluster 7.1.5 and I have remotes sites  with iphones 6921 and 7942.  when  caller from pstn is put on hold by 79XX and 69xx moh is working from ios flash. but when the call is internal. I mean when phone 7942 call to/from 6921 and 6921 put on hold to 7942 the moh work fine. but when 7942 put on hold to 6921. it is only hear tone on hold.  or when 6921 call to another 6921 no one can hear the moh.?

it is supported?, is any documents?

[Sajjit Rajagopal]

Tone on hold means that there is a config issue.

Things to check for Multicast tone on Hold:

n1.Check Multicast Configuration

n2.Incorrect Audio source id specified by holding party

n

n3.Held party doesn’t have an MRGL with MOH resource   

n4.Multicast not enabled  at audio source/MOH server/MRG

n

nCheck region setting between MOH server (g.711) - held party(g729)

Could you please clarify the following:

Is MOH working for calls in the same site ? calling and called party at the same site ?

Is MOH working for calls between main site and remote site ?

-Sajjit