Particles represent a communications data packet as a collection of noncontiguous buffers.
The traditional Cisco IOS packet has a packet type control structure and a single contiguous data buffer. A particle packet has the same packet type control structure, but also maintains a queue of particle type structures, each of which manages its own block. Allows concurrent use of the same region of memory. For example, on IP multicast a single packet is received and sent out on multiple interfaces simultaneously. To enable SRB over FDDI on the Cisco 7200 series routers, use the source-bridge interface command.