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

[John Fraizer]

Chad Brown wrote:

> 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.
> 
>  
> 
> Is this Nat messing with me or something else? In any case…Any advice 
> out there?
> 
>  
> 
> Thanks,
> 
> Chad
> 


The problem is probably that both of your SIP phones are using the same 
port.  I played with two 7960's behind a Linksys on Saturday and finally 
got them playing right when I changed the following:

In Phone 1's SIP[macaddr].cnf:

voip_control_port: 5061

In Phone 2's SIP[macaddr].cnf:

voip_control_port: 5062

The default control port is 5060.  Note:  This is the port that the 
PHONE uses to initiate the connection to * and not the port it is 
connecting to.

John