I cannot get my SIP phones to use Music on Hold. I can get it to work on 3CX and with an Android phone (using CSIPSimple) but not with my regular sip phones. Any Ideas where to start looking for a problem? I do not believe it is the phone since they do get the MOH to work with 3CX. I also do not believe that it is entirely Asterisk’s fault, because it does work with Android and if I set up a custom extension for MOH. Any help is appreciated.