в консоли это выглядит примерно так:
-- Started music on hold, class 'default', on channel 'SIP/kamailio-00000071' [root@ccng-360-demo-sip-asterisk-01 scripts]#
.... 30-40 секунд ....
> Locally RTP bridged 'SIP/kamailio-00000071' and 'SIP/kamailio-00000070' in stack [root@ccng-360-demo-sip-asterisk-01 scripts]#