Patent ID: 6226292
Filing Date: 2001-05-01
Classification: H04L

Abstract:
A method of operating a network switch having multiple ports each attached to a corresponding network link, comprising the steps of:determining whether a data frame received from a network link and stored in a receive buffer on the switch is a unicast frame to be transmitted on only one network link or is a multicast frame to be transmitted on more than one network link;transferring the frame from the receive buffer to an input data path of a set of transmit buffers used for temporary storage of data frames to be transmitted by the switch on network links attached thereto, each transmit buffer in the set being allocated for use with a corresponding network link attached to a corresponding different one of the switch ports, the set of transmit buffers having a periodic operating interval of predetermined duration defined as a write phase during which a portion of a data frame to be transmitted on one or more of the network links is to be written into one or more of the buffers;if the frame is a unicast frame, writing the frame during the transfer thereof into the transmit buffer allocated for use with the network link on which the frame is to be transmitted, multi-word segments of the frame being written into the buffer during successive write phases, each segment being written during a corresponding one of the write phases as a burst of data words at a predetermined rate; andif the frame is a multicast frame, writing the frame during the transfer thereof into the transmit buffers allocated for use with the network links on which the frame is to be transmitted, words of the frame being written into the buffers during successive write phases, each word being written during a corresponding one of the write phases to all the buffers for the network links on which the frame is to be transmitted, the buffers to be written being sequentially selected during each write phase at substantially the predetermined rate.