-- Executing Dial("SIP/603-08562cb0", "SIP/601") in new stack
    -- Called 601
    -- SIP/601-085740a0 is ringing
    -- SIP/601-085740a0 answered SIP/603-08562cb0
    -- Attempting native bridge of SIP/603-08562cb0 and SIP/601-085740a0

603 calls 601. They talk. 601 Transfers 603 to 602.

    -- Started music on hold, class 'default', on channel 'SIP/603-08562cb0'
    -- Executing Dial("SIP/601-08582a40", "SIP/602") in new stack
    -- Called 602
    -- SIP/602-08587f80 is ringing

602's phone is ringing, but 603 hears only silence.

    -- Stopped music on hold on SIP/603-08562cb0
  == Spawn extension (richmond, 601, 1) exited non-zero on 'SIP/601-08582a40<ZOMBIE>'
    -- Incoming call: Got SIP response 500 "Internal Server Error" back from 192.168.1.31
    -- SIP/602-08587f80 answered SIP/603-08562cb0

602 picks up and now 602 and 603 are able to speak with each other.

    -- Attempting native bridge of SIP/603-08562cb0 and SIP/602-08587f80
  == Spawn extension (richmond, 602, 1) exited non-zero on 'SIP/603-08562cb0'