Alcatel Network Systems, Inc.

Anthony J Mazzola

David W Kuddes

Cecil Mathews

A network element includes a plurality of routing circuits coupled by internal communication circuitry. Each routing circuit includes one or more external ports for communicating with external devices, one or more internal ports for communicating with other of the routing circuits, a database for storing address and path information received via the internal and external ports and circuitry for retransmitting address information received from an external device to other of the routing circuits.

Distributed routing network element

A message priority scheme for use in local areas networks (LANS) operating in accordance with carrier sense, multiple access/collision detect (CSMA/CD) bus access protocol. A LAN station having a high priority message to send ignores the carrier sense signal, and thereby obtains immediate bus access. If the high priority message collides with another message already on the bus, both messages are subject to a backoff period. However, the backoff period for a high priority message is guaranteed to be less than that of a low priority message for a certain number of re-transmission attempts. An intermediate priority status is assigned to a message that previously had a high priority status, after a certain number of transmission attempts. The intermediate priority message is deprived of its ability to transmit while ignoring the carrier sense signal, but retains its shorter backoff period.

Local area network with message priority

A system of managing memory used by communications tasks of a communications network operating with a multilayered communications protocol. Specially formatted buffers are used to contain data to be passed down the protocol stack of a source node, across a communications link, and up the protocol stack of a destination node. Before entering the source stack, message data is presegmented so that each buffer contains only so much message data as may be transmitted as a single data unit from source to destination, even after all layers of the source stack have added layer headers to that portion. Then, when the buffers are being passed within the source stack, any layer may segment the message data by simply unlinking buffers and adding its layer header to each segment. Inter-layer data passing is by means of exclusive access to buffers by one layer at a time. At the source stack, any layer that must send multiple copies of the message data may checkpoint the buffers and thereby regain the same buffers. At the destination stack, the buffers may be reassembled by relinking them.

Method for implementing a data communication protocol stack

A routing method, performed by intelligent network elements of a data communications network having SONET applications, for selecting a path from a source network element to a next network element. Each network element has access to a database containing the addresses of its neighboring network elements and their types. To select a next network element, a routing network element first attempts to find a neighboring network element that is the same as the destination network element. If it has no such neighbor, the routing network element then attempts to find a neighbor that is in the same area as the destination, or failing such a neighbor, in the same routing domain. Optionally, the routing network element looks for a neighbor that has been selectively provisioned as a next network element. At each step, candidate network elements are eliminated by using data about their type and application to determine if they call for duplicate paths.

Growing community of inventors

Plano, TX, United States of America

Anthony J Mazzola