*Why do we need this extension
tag?*
--We can know if a UA is behind the NAT by
verifying if the Src IP address ( NATed incase of NAT ) is the same as the IP
address mentioned in the Contact header of the REGISTER message.
[RAVI}> First of all, Contact need not have an IP
address. It may just be an e-mail address
or
some URL. Secondly, even if it did have an IP address, it need not be same as
the source
IP
address, even in a non-NAT scenario. There is no restriction that
registration should be done
from
the same IP address to which Contact is being
set.
regards,
ravi.
Best Regards'
Rahul
