NAT question.. Can someone please verify for me?

Hi all,

I have an asterisk box setup using a public IP. I have several phones on that same network using public IP’s as well. However, I also have several phones on a different network behind a NAT.

When I do a sip show peers in the asterisk console the phones that are behind that NAT all show up as having the same IP address (the public IP of the NAT box).

Because of this configuration, I am not able to call between the phones that are behind the NAT. I have phones 1-5 behind the NAT. I can’t call from phone1 to phone2 because only one can register at that IP at one time.

Can I fix this by having a second asterisk box on the network behind the NAT and just configuring IAX to talk between the two? Or is there a better way to do this?

I can’t change the router or anything like that because it is actually on a school campus. Could someone please just give me some ideas on how to achieve this? I would like to have all phones talking to each other and talking to the PSTN lines as well.

Thanks in advance!

Do you have host=dynamic for those sip peers, or are you specifying the IP? Also have canreinvite=no and maybe even nat=yes
Add the nat=yes last since I’m not sure that will actually do anything in your situation since * is on a public IP.

Sure you can go the additional asterisk route, but try the above ideas first.