Port aggregation protocol

A device for use in a computer network, the device comprising:

• a plurality of physical ports for use in connecting the device to neighboring devices;
• means for receiving aggregation protocol data units (AGPDUs) generated and forwarded by the neighboring devices at two or more of the physical ports, each AGPDU containing a unique identifier corresponding to the neighboring device that generated the AGPDU and a port number associated with the port through which the AGPDU was forwarded;
• means for determining whether two or more of the physical ports are directly coupled to the same neighboring device, based on the information contained in the received AGPDUs;
• and
• means for aggregating physical ports singularly coupled to the same neighboring device into a single, logical aggregation port.

An aggregation data protocol unit (AGPDU) for use in aggregating a plurality or redundant links connecting corresponding physical ports of first and second neighboring devices of a computer network into a single, logical aggregation port, the AGPDU generated and forwarded by the first neighboring device and stored in a memory associated with the second neighboring device, the AGPDU comprising:

• a first field containing a unique identifier corresponding to the first neighboring device;
• a second field containing a value associated with the physical port through which the AGPDU is forwarded and to which a respective redundant link may be coupled;
• a third field that may contain a unique identifier corresponding to the second neighboring device;
• and
• a fourth field that may contain a value associated with the physical port through which the AGPDU is received at the second device.

A computer readable medium containing executable program instructions for aggregating a plurality of redundant links connecting corresponding physical ports of neighboring devices in a computer network, the executable program instructions comprising program instructions for;

• generating an aggregation protocol data unit (AGPDU) at each of two or more physical ports of a first neighboring device, each AGPDU including a unique identifier corresponding to the first neighboring device and a port number associated with the respective physical port;
• forwarding each AGPDU through the respective physical port for receipt by one or more neighboring devices at corresponding physical ports;
• based on the information contained in AGPDUs received at a second neighboring device, determining whether two or more physical ports are directly coupled to two or more physical ports at the first neighboring device by respective redundant links;
• and
• aggregating the two or more physical ports directly coupled to the first neighboring device into a single, logical aggregation port.

An intermediate network device for use in forwarding messages in a computer network, the computer network including one or more devices configured to transmit aggregation protocol data unit (AGPDU) messages, each AGPDU message carrying a device identifier and a port identifier that correspond to the device transmitting the AGPDU and the port through which the AGPDU is transmitted, the intermediate network device comprising:

• a plurality of physical ports in communicating relationship with the one or more AGPDU-capable devices;
• a plurality of aggregation state machine engines, each engine associated with a corresponding physical port and configured to capture and process AGPDU messages received at the corresponding physical port;
• and
• a partner table associated with and accessible by each aggregation state machine engine,
• wherein, in response to receiving an AGPDU message from a first neighboring device at a first physical port, the corresponding aggregation state machine engine copies at least the device and port identifiers from the received AGPDU message into the corresponding partner table, and further wherein the corresponding aggregation state machine engine queries the partner tables associated with the other physical ports to determine whether other physical ports have received AGPDU messages from the first neighboring device.

An intermediate network device for use in forwarding messages in a computer network, the computer network including one or more devices capable of transmitting aggregation protocol data unit (AGPDU) messages containing information, the intermediate network device comprising:

• a plurality of physical ports in communicating relationship with the one or more AGPDU-capable devices;
• and
• a plurality of aggregation state machine engines, each engine associated with a corresponding physical port and configured to capture and process AGPDU messages received at the corresponding physical port and to transition the physical port among one of idle, transmission, linked, available and aggregated states, in response to the receipt of AGPDU messages and the information contained therein,
• wherein the idle state corresponds to a physical port unable to transmit network traffic, the linked state corresponds to a physical port able to transmit network traffic, the linked state corresponds to the receipt of one or more AGPDU messages at the respective physical port, the available state corresponds to the physical port being directly coupled to a neighboring device and the aggregated state corresponds to the respective physical port being aggregated with one or more other physical ports that are directly coupled to the same neighboring device.

In an intermediate network device having a plurality of physical ports in communicating relationship with one or more neighboring devices through respective links, the one or more neighboring devices capable of transmitting aggregation protocol data unit (AGPDU) messages, each AGPDU message carrying a device identifier and a port identifier that correspond to the device transmitting the AGPDU and the port through which the AGPDU is transmitted, a method of aggregating a plurality of redundant links coupled to a first neighboring device, the method comprising the steps of:

• receiving one or more AGPDU messages from the first neighboring device at two or more physical ports of the intermediate network device;
• based on the identifiers contained in the one or more received AGPDU messages, determining that the two or more physical ports of the intermediate network device are directly coupled to the first neighboring device by respective redundant links;
• and
• aggregating the two or more physical ports that are directly coupled to the first neighboring device into a single, logical aggregation port.