Limit number of simultaneous calls on Asterisk based SIP Trunk.
If you want to limit the number calls for your SIP peer or friend in Asterisk use call-limit in your trunk configuration.
Create a trunk:
trunkname
type=peer
host=HOST IP ADDRESS
qualify=no
context=from-trunk
dtmf:rfc2833
call-limit=30
This will create a SIP trunk and the max number of calls allowed on the SIP Trunk will be 30.
call-limit = number : Number of simultaneous calls through this user/peer.
These configurations can be used for any soft switch based on Asterisk.
Examples are Elastix, PIAF, Trixbox