8-18 Port Buffer ConfigurationWhen configuring port buffers, go to these sections for information you are interested in:z Port Buffer Overviewz Configuring the Shared Bufferz Displaying and Maintaining Port Bufferz Burst Configuration ExamplePort Buffer OverviewThe S5810 supports transmit and receive buffering for ports to eliminate packet loss when traffic isarriving at a rate greater than the physical medium can support or when forwarding decision is made.With the buffering implementation of the switch, the buffer memory is divided into a shared buffer areaand a dedicated buffer area. The shared buffer area is shared by all ports and is user configurable. Theremaining buffer memory after the shared buffer area is deducted is the dedicated buffer area, which isassigned evenly among the ports. The dedicated buffer memory of a port cannot be shared by any otherports and is used prior to the shared buffer. A port uses the shared buffer only when its dedicated bufferis inadequate.Two approaches are available for you to set the shared buffer:z Configuring the Burst Function to Automatically Set the Shared Bufferz Configuring the Shared Buffer ManuallyWhen manually setting the shared buffer area, take the traffic pattern in your network into consideration.If transient large traffic bursts may occur on some ports, expand the shared buffer to accommodate thebursts to prevent traffic loss. If transient small traffic bursts often occur on the ports, decrease theshared buffer so that each port can get more dedicated buffer memory.The following are two scenarios where a larger shared buffer may be preferred to improve forwardingperformance:z Broadcast or multicast traffic is dense, and large transient traffic bursts are likely to occur.z A low-speed link is being used to forward high-speed traffic or an interface is forwarding trafficreceived from multiple interfaces that work at the same rate as it.Configuring the Shared BufferConfiguring the Burst Function to Automatically Set the Shared BufferWith the burst function configured, the switch automatically configures the shared buffer size, andassigns the remaining buffer memory (the dedicated buffer) evenly among all ports.Follow these steps to configure the burst function:
