Wellfleet Communications Inc, of Bedford, Massachusetts, a specialist in multiprotocol router-bridges, has announced two new software features, Extended Source Routing and Source Routing End Station Support, which are designed to enable construction of large IBM Corp source-route bridging networks. Extended Source Routing enables IBM users to overcome the limitations inherent in IBM source-route bridging protocol. In networks stretching across wide-area links, users are bound by the IBM limit of seven hops per network, with each bridge-ring combination corresponding to one hop. Wellfleet source-route bridges create a boundary at the entry point to the network. From the source-route bridging end station perspective, a network of routers represents only one hop to any destination, regardless of the number of nodes data passes through. As a result, users can build a network as large as required, regardless of the actual number of hops. The Extended Source Routing bridge builds a routing table with route designators from each source-route bridging explorer packet it receives. The bridge then discards route designators in subsequent frames that it receives, effectively setting the hop count at zero again. Extended Source Routing maintains compliance with the IEEE source-routing transparent standard – 802.1D – and is therefore interoperable with other source-routing transparent bridges. Source Routing End Station support was developed to enable routing and bridging to coexist in the same IBM source-route bridging network. When Source Routing End Station Support is enabled, end stations that support both source-route bridging and a routing protocol such as IP, IPX or AppleTalk, are able to use source-route bridging within a facility and then routing between the routers and the rest of the network. Extended Source Routing and Source Routing End Station Support are now available at no charge to customers covered by Wellfleet’s Software Subscription Service. The software runs on Wellfleet’s Feeder Node, Link Node and Concentrator Node router-bridges. The scalable product family supports from one to 26 local network connections and from one to 52 wide-area network connections. It routes all major local network protocols, including AppleTalk, DECnet, IPX, TCP/IP and XNS. Bridging of protocols such as DEC’s Local-Area Transport is simultaneously supported through Wellfleet’s Spanning Tree Bridge.
