[asterisk-dev] users and peers (and phones and trunks) ?

[Luigi Rizzo]

This is related to chan_sip, but maybe it applies to other parts
of asterisk as well.

I have a doubt on why we have "users" and "peers" - in other words,
is there some limitation that we want to enforce, or some feature
that we want to enable, by by declaring a device in one or the other
category ?  Is there anything we would miss if we just defined
everything as a "peer" (in chan_sip terminology) and drop the "user"
category altogether ?  That would make the code a lot simpler, with
a big impact on the configuration simplicity as well.

E.g. when i have an ATA, a hardphone, softphone, another asterisk
or a provider, i always end up declaring them as "peer" (or "friend",
but i really don't know why!), and the only think i make sure of
is to establish the connections by either declaring the other
device's IP/port, or expecting it to register to me.

Is there something else i am missing that motivates the existence
of two different categories ?

(note: i mention phones and trunks because i am unclear on what these
terms mean too. Sometime i think of a phone as a leaf device,
but that's probably a useless definition, because people always
find a way to interface a leaf device to some other piece of
equipment and then play tricks to tunnel data over whatever
existing channel exists...)

	cheers
	luigi