International Business Machines Corporation

3com Corporation

3 Com Corporation

John Griesing

James L Moran

Carl John Lindeborg

Anthony D Walker

Bradley S Trubey

David E Bartolini

Edward Carroll

Liz Lindell

Craig Owens

A peripheral device for use with a computer. The peripheral device includes a data path, a control circuit coupled to the data path for controlling data communication and a port. The port includes a connector used by the data path. The connector includes a first set of pins that are used by the data path and a second set of pins that are not used by the data path. The first set of pins are coupled to the data path for data communication from the data path to the computer, and the second set of pins coupled to the control circuit for providing access to the control circuit from the port.

Device for out-of-band transmission on computer peripheral

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

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Santa Clara, CA, United States of America

John Griesing