Network having at least two routers, each having conditional filter so

Abstract

A hierarchical wide-area network architecture which conforms to the DLSw protocol is provided, in which multiple routers having a logical connection to one another are designated as a peer group. At least one router in each peer group is designated as a border peer, and functions as a gateway between the members of its group and other peer groups. The peer group structure reduces broadcast traffic on slow links by changing the source of the broadcast from a small access router with a relatively slow link to another, more powerful router, with a faster link on the network. More than one border peer can be included in each group, to share the transmission workload and act as a backup. The border peers can share information about the groups that they service and can cooperate to provide a single-point broadcast service to all of the users of the service. When two or more routers are connected to a network in parallel to provide back-up facilities, conditional filters are employed to prevent redundant operations. Different types of frames are handled by the two different routers, so that they share the communication load between them and make the most effective use of the available bandwidth.