[asterisk-users] Curious what 'early media' is in terms of Answer()

[Hose]

http://www.voip-info.org/wiki/index.php?page=Asterisk+cmd+Answer

Can someone clarify what "early media" is?  I noticed that NOT answering
a call before dumping them into a queue that has music on hold will not
set up a leg to push music back over the calling SIP channel.  Tossing
an Answer command into the dialplan just before moving to the queue
alleviates this (in either situation the queue still works when someone
picks up the queued call).

This is more of a trivial question, but I'm interested in knowing where
(if anywhere, or if it's played at all) the music on hold is going when
there is no Answer command.  Incidentally, in 1.6.1.x the Answer appeared to be
explicit after dumping a call into a queue, which is how I came across
this issue after upgrading to 1.6.2.11.

hose