Interface address used for sending/receiving packets to/from the session destination
$ifdst = IP address or FQDN
It is an interface address used for sending/receiving the packets to/from the session destination (UAS). This address is used for the values in Via, Record-Route headers.
$ifdst = 192.168.0.100
Set 192.168.0.100 as an interface address for the sending packets to the destination.