Connection question/testing help

I have another problem that is outside my skillset that I need a little help with.

I have an ATA that I can connect onto the physical network with my asterisk server and it works perfect. BUT when I take it to my office and connect it to my office network and point it to the public IP address for my Asterisk network it does now work. My office is on a shared network that is administrated by the building.

My asterisk box is at home on Fios, the Fios firewall is DMZ’s pointing to the Asterisk box. I can telnet to the Asterisk box from work so I know the connection is working point to point.

The asterisk box has a static IP Address (, and the router/firewall has it’s DMZ pointing to this address and active.

My office has a firewall/router that is then connected to the building Internet…

With the ATA at home it works, I can make outgoing calls call other extensions etc. When connected from the office it cannot register with Asterisk.

I suspect one of two things: the building is blocking the SIP ports, OR I have somehow setup the extension such that asterisk will not allow it to connect from a foriegn Network IP address or possibly that the device isn’t liking the NAT routers that are in the middle of all this.

What steps can I take to test the above situations and narrow down the problem???

Wanting to make your home calls thru your office line :stuck_out_tongue: nice…

make sure nat=yesunder the definition for the ATA in sip.conf/users.conf

also make sure you specify externip in sip.conf

If it still doesnt work, give some debug info and put up ur sip.conf etc.