Allow only specific IP...

[starion]

Someone has been ringing our office phones from outside of our PBX, i.e. they are sending directly to our IP. (Our PBX is remote from our office).

Is there a way in the T38G phone to limit incoming traffic to a specific IP, i.e. our PBX?

I know this could also be a firewall/router setting, but in many cases, the IP phones are on networks in which we have no access to the router settings, so I'm looking for a solution within the phone itself.