How to turn off Netopia 3000 (SIP ALG) off to have your DSL setup work with VOIP systems.
*Netopia has SIP Passthrough "on" by default. (Or SIP ALG in newer models) In order to work with 3NG Networks, you must turn SIP Passthrough (SIP ALG) off.
The setting is not in the web gui. You have to telnet into the router, then type. Each line is a new command.
telnet 192.168.1.254 (default netopia ip)
login: admin
password: device access code on the back of the router
Type the following into the telnet session and hit enter after each line
configure
set ip sip-passthrough off
save
exit
Restart
Once system has rebooted the SIP-ALG will have been disabled.