Queue resynch: synchronous real-time upgrade of a distributed switching system

A method for switching packets comprising the steps of:

• receiving packets at a port card of a switch from a network;
• sending fragments of each packet to fabrics of the switch;
• distributing control information from a switch control processor to the fabrics of the switch as the port card continues to receive packets;
• receiving a control initiation signal from the switch control processor through the network at the port card;
• sending the control initiation signal from the port card to the fabrics;
• implementing the control information at each fabric only after the respective fabric receives the control initiation signal so all the fabrics implement the control information at the same time, and entering a queue resynch state by each fabric when the respective fabric implements the control information;
• and
• dequeueing any packet fragments received by the fabric before any new packet fragments received by the fabric after the fabric has entered the resynch state are dequeued.

A switch of a network connected to a switch control processor comprising:

• port cards which receive packets from and send packets to the network, each port card includes a striper;
• a switch control processor for providing control information;
• and
• fabrics for switching the packets, the fabrics receiving control information from the switch control processor but all the fabrics only implementing the control information at a same logical time when each fabric receives a control initiation signal from one of the port cards, each respective fabric continuously operating on packets before, during and after each respective fabric receives the control initiation signal, the striper sends to each fabric a respective fragment of each packet as a stripe and also generates a parity stripe for error detection and correction, the fabrics connected to the switch control processor and the port cards.

A method for switching packets comprising the steps of:

• receiving packets at a port card of a switch from a network;
• sending fragments of each packet to fabrics of the switch as stripes and producing a parity stripe for error detection and correction;
• distributing control information from a switch control processor to the fabrics of the switch as the port card continues to receive packets;
• receiving a control initiation signal from the switch control processor through the network at the port card;
• sending the control initiation signal from the port card to the fabrics;
• and
• implementing the control information at each fabric only after the respective fabric receives the control initiation signal so all the fabrics implement the control information at the same time.