Externip and nat in sip.conf


How does exactly exterip in sip.conf works in nat environment ?
It is replacing the IP address in UDP (SIP payload) ?
Or is it replacing real ip address ?
Could anybody give example of such sip session ?
(or point me to appriopriate dodumentation if it exists - i could not find)


Externip is your WAN ip address of your network that the internet sees. In other words your NAT will send and receive data with this address to external hosts. However your nat would have memorized each session information so that as it sends and receives data it knows what Local IP address belongs to what session and what data belongs to each session and Local IP address. Same thing happens at the network you are communicating with.

See this thread for some setting info; forums.digium.com/viewtopic.php? … ight=drwho