[Asterisk-Users] 2 Sip phones behind un-natted Asterisk

[Senad Jordanovic]

>> I have 2 SIP phones (Cisco 7960 & XTen) behind a NAT provided by a
>> Linksys firewall that supports UPnP.  The Asterisk server has a
>> public IP. Here are the problems that I am having with this
>> configuration... 
>> 
>> 
>> 
>> 1.	The 2 SIP phones can call MeetMe and have a conference but
>> cannot call each other. (Yes, they connect but no audio either
>> direction) 
>> 2.	I have verify=yes in the sip.conf for both phones. Both phones
>> constantly go Unreachable. (However, the connection is very fast
>> between * and sip phones)
>> 3.	Sometimes but not always when I try to call phone1 phone2 rings.

Have you tried to make sure that each user agent use differnet sip port?