Explain the use device status system implemented in SIP for subscriptions,

queues and manager a bit better.

Like in 1.2, you will get more detailed information if you set a call 
limit for a device. When the call limit is reached, the status system will
report a device as busy.

For queues, setting a call limit per SIP device is propably a requirement.

In most cases, it will work much better if you only use type=peer and not
type=friend. We might decide to backport the new setting from trunk to
apply all call limits to the peer part of a friend only.



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@48113 65c4cc65-6c06-0410-ace0-fbb531ad65f3

configs/sip.conf.sample

@@ -164,6 +164,15 @@ srvlookup=yes			; Enable DNS SRV lookups on outbound calls
 ; You can subscribe to the status of extensions with a "hint" priority
 ; (See extensions.conf.sample for examples)
 ; chan_sip support two major formats for notifications: dialog-info and SIMPLE 
+;
+; You will get more detailed reports (busy etc) if you have a call limit set
+; for a device. When the call limit is filled, we will indicate busy. Note that
+; you need at least 2 in order to be able to do attended transfers.
+;
+; For queues, you will need this level of detail in status reporting, regardless
+; if you use SIP subscriptions. Queues and manager use the same internal interface
+; for reading status information.
+;
 ; Note: Subscriptions does not work if you have a realtime dialplan and use the
 ; realtime switch.
 ;