Inside Cisco IOS Software Architecture (CCIE Professional Development)

Buffer Management Using Particles

Particle buffering uses a scatter-gather approach for packet buffer memory management. Instead of allocating one piece of contiguous memory for a buffer, particle buffering allocates dis-contiguous (scattered) pieces of memory, called particles, and then links them together (gathers) to form one logical packet buffer, called a particle buffer. With this scheme, a single packet can be spread across multiple physical buffers.

Particle buffers are built—that is, individual particles are linked together—as each packet is received on an interface, as you'll see when you study the Cisco 7200 router example. This method differs from that of contiguous buffers, which need no assembly before use. As a result, there are ...