3Com AccessBuilder 500 User Manual - Building A Larger Network

Bridging and Routing Concepts

A-5

The AccessBuilder 500 uses FastConnect, its own protocol, to ensure the 

most efficient connection with other AccessBuilder units. However, if you 

are connecting to a different type of bridge/router the standard PPP 

communications protocol is required to establish the link. You can 

configure outgoing calls to use either FastConnect or PPP as required. The 

ISDN port on the AccessBuilder 500 autosenses the protocol being used on 

incoming calls and switches to the protocol necessary for that connection.

If you are using ISDN to connect to different networks, the two B 

channels can be used independently to connect to different networks 

at the same time.

Building a Larger Network

Large networks of interconnected LANs can be established by using 

multiple bridges as illustrated in 

Figure A-2

. 

The bridges build up their address tables. If the destination unit is not 

registered as being accessed via the bridge’s LAN interface, the frame 

will not be placed on LAN A. Therefore, frames passing between LAN B 

and LANs C or D will not impact the overall performance of the LAN.

Figure A-2   

Multiple Remote Bridges