3com Corporation

International Business Machines Corporation

Chipcom Corporation

David E Bartolini

Anthony D Walker

Bradley S Trubey

James L Moran

Carl John Lindeborg

Yuval Shohet

Brian Ramelson

Yoseph Linde

Gordon C Saussy

John L Cook, Iii

Menachem Abraham

John Griesing

Ilan Carmi

Samuel Ben-Meir

Alex Herman

Ira Hart

Igor Zhovnirovski

Liz Lindell

Edward Carroll

Richard Rehberg

Yongbum Kim

Steven E Horowitz

Kenneth T Wilson

Jay L Smith

A token ring network performs address to port mapping by taking advantage of the abilities of the port switched modules and the neighbor notification process, in order to perform address to port mapping on each individual module. Ring monitors are switched from an upstream side of a port to a downstream side of a port when the neighbor notification process enters the port domain. The processor on the module records all the addresses received on the downstream side of the port, when the neighbor notification process is in the domain of that port. If it appears that the neighbor notification process is in the domain of two adjacent ports, the present invention only records addresses from the most downstream of the two adjacent ports, since such a situation is an indication that the upstream ports do not conform to MAC protocol. If a non-protocol station is connected to the last port in a module, the module will collect addresses from that port until the neighbor notification process enters the most upstream port of the module. At that point, addresses are no longer recorded in the most downstream port, and each set of addresses for each port are checked to determine if the last entry in each port has the ARI bits set to one and the source address is similar to the address of the most upstream neighbor of the module. If the addresses are the same, all addresses recorded in that port are ignored, since that port contains a non-protocol station.

Method and apparatus for address to port mapping in a token ring network

Beacon recovery is performed separately on each module. After a module recognizes that a beacon condition has occurred, each module checks to determine if the defect or fault is on its module. If the defect is on the respective module, the module disconnects itself from the remaining modules in the network and transmits a beacon frame onto an upstream end of the group of stations on that module. Each port on the module is then tested to determine if the error lies in the corresponding station. This testing is based on the presence or absence of the beacon frame.

Method and apparatus for correcting a defect in a token ring network

In a serial network which includes a hub having a plurality of ports each for attaching one or more stations a mechanism for correlating a list of stations developed in a poll cycle to the ports and for detecting and resolving ambiguities when the number of stations does not equal the number of active ports. The mechanism uses a combination of input and output buffers under control of the programmed hub processor for developing a list of stations connected to the hub. When the number of stations does not equal the number of active hub ports an upstream buffer is configured to transmit Duplicate Address MAC frames to a single port and the contents of a downstream buffer are used to resolve the ambiguity either on a single transmission or multiple single port transmissions.

Port address resolution device

A local net area network, or LAN, configuration is provided with a multiple generic LAN channel architecture which can be logically and dynamically changed. The configuration control can be applied to each module of the network and to each port of a module of a LAN hub. The architecture provides multiple LAN protocols to be used simultaneously, as needed, through protocol specific functions. Industry standard protocol such as: token bus, token ring, and fiber distributed data interface (FDDI), can be implemented using the generic channel architecture and its characteristics providing respective network functions. The architecture also provides a digital collision detection method and provides information necessary for precise network statistics monitoring. The token passing ring architecture provides a logical ring formation within the generic channel. A token passing bus architecture uses modified Ethernet.TM. architecture, and a hub management provides control for the generic multichannel and the LAN management provides protocol dependent network management. The architecture provided allows multiple hub management entities via hub mastership arbitration to provide a unique master for the hub management function.

Generic backplane system which is configurable to serve different

Communication system concentrator configurable to different access

Growing community of inventors

Dudley, MA, United States of America

David E Bartolini