Switching node with load balancing of bursts of packets

A method of controlling switching in a packet switching node, the method comprising:

• determining whether to distribute the flow, wherein packets belonging to the flow is received at the node, the packets being assembled into bursts of packets, the bursts being groups of consecutive packets belonging to the flow, each burst having a burst control packet, the burst control packet indicating a sequence of the burst in the flow;
• selecting, if the flow is to be distributed, at least two of the links to use for sending on the bursts of the flow towards the destination node;
• and
• distributing the bursts of the flow between the selected links by:
• forwarding a first of the bursts for switching to a first output port, for transmission over a first of the selected links;
• and
• forwarding a second of the bursts for switching to a second output port, for transmission over a second of the selected links according to the indicated sequence for the flow.

A method of operating a packet switching node coupled by links to other nodes, as an egress node, the method comprising:

• receiving at line input ports, bursts of packets being groups of consecutive packets belonging to a specified packet flow, sent over different links from another node, each burst having a burst control packet, the burst control packet indicating a sequence of the burst in the flow;
• selecting a local output port for packets of the flow;
• switching the bursts to the selected local output port;
• and
• ordering the packets of the bursts of a same flow, according to the indicated sequence.

A method of operating a packet switching node coupled by links to other nodes, as an intermediate node, the method comprising:

• receiving at line input ports, bursts of packets being groups of consecutive packets belonging to a specified packet flow, sent from another node, each burst having a burst control packet, the burst control packet indicating a sequence of the burst in the flow;
• determining if the flow is distributed;
• upon determining the flow is not distributed, determining whether to distribute it over different links to different adjacent nodes;
• upon determining the flow is distributed and to be combined, determining whether to recombine it;
• upon determining the flow is distributed and not to be recombined,
• selecting at least two of the links to use for sending on the bursts of the flow towards a destination node, and
• distributing the flow between the selected links by:
• forwarding a first of the bursts for switching to a first output port, for transmission over a first of the selected links;
• and
• forwarding a second of the bursts for switching to a second output port, for transmission over a second of the selected links according to the indicated sequence for the flow.

A traffic controller for controlling a packet switching node coupled by links to other nodes, the node comprising:

• a local input port for receiving packets belonging to a specified packet flow, to be sent on to a destination node,
• a burst assembler for assembling the received packets of that flow into bursts of packets, the bursts being groups of consecutive packets belonging to the flow, each burst having a burst control packet, the burst control packet indicating a sequence of the burst in the flow, to enable the sequence to be maintained after transmission, and
• a switch coupled to the local input port and to output ports, the traffic controller being arranged to perform the following:
• selecting at least two of the links to use for sending on the bursts of this flow towards the destination node;
• and
• being coupled to the burst assembler to distribute the flow between the selected links by forwarding a first of the bursts from a first burst assembler queue to the switch for switching to a first output port, for transmission over a first of the selected links, and by forwarding a second of the bursts from a second burst assembler queue to the switch for switching to a second output port, for transmission over a second of the selected links.

A packet switching node coupled by links to other nodes, the node comprising:

• a local input port for receiving packets belonging to a specified packet flow, to be sent on to a destination node,
• a burst assembler for assembling the received packets of that flow into bursts of packets, the bursts being groups of consecutive packets belonging to the flow, each burst having a burst control packet, the burst control packet indicating a sequence of the bursts in the flow, to enable the sequence to be maintained after transmission,
• a switch coupled to the local input port and to output ports, and
• a traffic controller being arranged to perform the following:
• selecting at least two of the links to use for sending on the bursts of this flow towards the destination node;
• and
• being coupled to the burst assembler to distribute the flow between the selected links by:
• forwarding a first of the bursts from a first burst assembler queue to the switch for switching to a first output port, for transmission over a first of the selected links, and
• forwarding a second of the bursts from a second burst assembler queue to the switch for switching to a second output port, for transmission over a second of the selected links.