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