--- no music on hold, some unknown reason ---
jachin*CLI>

    -- Executing Dial("SIP/66.54.140.46-08900000", "SIP/998|180") in new stack
    -- Called 998
    -- SIP/998-11bb is ringing
    -- SIP/998-11bb answered SIP/66.54.140.46-08900000
    -- Attempting native bridge of SIP/66.54.140.46-08900000 and SIP/998-11bb
    -- Started music on hold, class 'default', on SIP/66.54.140.46-08900000
    -- Stopped music on hold on SIP/66.54.140.46-08900000
    -- Started music on hold, class 'default', on SIP/66.54.140.46-08900000
    -- Stopped music on hold on SIP/66.54.140.46-08900000
    -- Started music on hold, class 'default', on SIP/66.54.140.46-08900000
Nov  7 20:06:11 WARNING[426]: chan_sip.c:697 retrans_pkt: Maximum retries exceeded on call 473ab2205e8477684abb7d525b20b8d2@66.228.198.77 for seqno 12360 (Non-critical Response)

--- with music on hold, calling from different source, same extension ---

jachin*CLI>
    -- Accepting AUTHENTICATED call from 198.22.67.70, requested format = 2, actual format = 2
    -- Executing Dial("IAX2/NuFone@NuFone/1", "SIP/420&SIP/998|20|t") in new stack
    -- Called 420
    -- Called 998
    -- SIP/420-30a7 is ringing
    -- SIP/998-f24f is ringing
    -- SIP/998-f24f answered IAX2/NuFone@NuFone/1
    -- Started music on hold, class 'default', on IAX2/NuFone@NuFone/1
    -- Stopped music on hold on IAX2/NuFone@NuFone/1
    -- Started music on hold, class 'default', on IAX2/NuFone@NuFone/1
    -- Stopped music on hold on IAX2/NuFone@NuFone/1
  == Spawn extension (incoming, 8777770420, 1) exited non-zero on 'IAX2/NuFone@NuFone/1'
    -- Hungup 'IAX2/NuFone@NuFone/1'