Details

Returns actual number of pages that can be allocated. Actual allocation happens when the sys.buffalloc method is used. The socket is unable to RX data if its RX buffer has 0 capacity. Actual current buffer capacity can be checked through the sock.rxbuffsize which returns buffer capacity in bytes.

Relationship between the two is as follows: sock.rxbuffsize=num_pages*256-16 (or =0 when num_pages=0), where "num_pages" is the number of buffer pages that was GRANTED through the sock.rxbuffrq. "-16" is because 16 bytes are needed for internal buffer variables.

Buffer allocation will not work if the socket port to which this buffer belongs is not idle (sock.statesimple is not at 0- PL_SSTS_CLOSED) at the time when sys.buffalloc executes. You can only change buffer sizes of sockets that are idle.