HP UX Internet and Networking Software manual Buffers communicationnumber buffersize

NET.CFG Options Reference

Link Support Option

BUFFERS communication_number [buffer_size]

Configures the number and size of receive buffers that the Link Support Layer (LSL) manages.

Communication Number The number of communication buffers must be large enough to hold all protocol headers and the maximum data size. If you make many connections, you should increase the number of buffers to increase performance.

If the protocol you are using builds the media header (MAC) for the LAN driver, then you need to set the buffer size large enough to manage the header also.

For example, IPX requires 512 bytes (LAN header) + 74 bytes (protocol header) + 52 bytes (MAC) = 638 bytes.

See the manufacturer’s specifications for possible parameters and values required for third-party protocol stacks.

Buffer Size The total buffer size must share a 64KB segment with the mempool and resident program code from the LSL.COM file when loaded into memory (approximately 5 KB).

This means that the communication number multiplied by the buffer size (plus the code size and mempool) cannot be greater than 65,536 bytes.

For example, 20 communication buffers multiplied by a buffer size of 1514 bytes equals 30,280 bytes.

Syntax

buffers communication_number [buffer_size]

Replace communication_number with a number of buffers greater than 1.

Replace buffer_size with a number of bytes greater than 638.

The buffer size is optional.

2-47