ZyXEL Communications Prestige 480 - Manual (Page 224)

Prestige 480 Dual BRI ISDN Router
16-2 Troubleshooting
The Prestige drops the
call even though the
authentication phase
was successful. Check the IP address of the remote node. The Prestige uses the IP address
as another form of authentication. Hence, if the address supplied by the
remote node does not match the address the Prestige is expecting, the call will
be dropped.
You can rectify this problem by using the Internet Access Setup Menu 4 to
configure your remote node.
You can enter the ISP’s IP address field as 0.0.0.0. In this case, the Prestige
will accept any IP address sent from the device and the call won’t be dropped.