Routing Ip Over Isdn; Figure - Bay Networks NauticaRS Reference Manual

Routing IP over ISDN

117237-E Rev.00
• A Nautica router can be configured to act as a Network
Access server (NAS) in networks where Remote
Authentication Dial-In User Service (RADIUS)
authentication is used.
• Comprehensive filtering, by source and destination IP
address, port number and protocol type, provides security for
sensitive applications and optimizes WAN use.
The Nautica routers can connect to other networks using ISDN,
just as if the network were attached with a leased line. A path,
with the ISDN number of the device at the remote network, is
used to make the connection.
When data is sent to the remote network, the Nautica router will
automatically dial the ISDN number associated with the router
advertising the destination IP network address. The Nautica
router is able to match the ISDN telephone number to a given IP
address by first checking the path associated with the destination
address, and then inspecting the path to determine the ISDN
number to be dialed.
During the initial setup of a Nautica router, the system
administrator instructs the router to call any remote routers which
are to be part of the network. The router then automatically learns
about those units and creates its routing address table. This makes
it very easy to set up a Nautica Series router, and it is less prone to
user input errors.
The Nautica routers also support a feature called unnumbered
links. This means that the system administrator does not have to
configure an inter-router network for the path. This reduces the
number of network addresses needed, because you no longer need
to address each link separately, with a consequent reduction in the
configuration overhead. Hence the Nautica router is able to
support multiple ISDN lines to various destinations, based on the
needs of the organization, rather than having all the possible
destinations pre-programmed, as is the case with other routers.
Introduction to Protocols and Routing
1-7