This option is used to adjust the internal buffer size allocated for the receive buffer. The buffer size may be increased for high-volume connections, or decreased to limit the possible backlog of incoming data. This request is not an absolute requirement. The implementation may place upper and lower limits on the option value. Requests that fall short of the lower limit are negotiated to the lower limit.
Legal values are all positive numbers.
This option is used to set a low-water mark in the receive buffer. The option value gives the minimal number of bytes that must have accumulated in the receive buffer before they become visible to the transport user. This request is not an absolute requirement. The implementation may place upper and lower limits on the option value. Requests that fall short of the lower limit are negotiated to the lower limit.