Sun Microsystems X1150A - Manual (Page 67)

Chapter 4 Configuring Driver Parameters 45
Random Early Drop Parameters
TABLE 4-8 describes the RX random early detection 8-bit vectors, which allows you to
enable random early drop (RED) thresholds. When received packets reach the RED
range packets are dropped according to the preset probability. The probability
should increase when the FIFO level increases. Control packets are never dropped
and are not counted in the statistics.
TABLE 4-8 RX Random Early Detecting 8-Bit Vectors
Field Name Values Description
red-dv4to6k 0 to 255 Random early detection and packet drop vectors for
when FIFO threshold is greater than 4096 bytes and less
than 6,144 bytes. Probability of drop can be
programmed on a 12.5 percent granularity. For
example, if bit 0 is set the first packet out of every eight
will be dropped in this region. (Default=0)
red-dv6to8k 0 to 255 Random early detection and packet drop vectors for
when FIFO threshold is greater than 6,144 bytes and
less than 8,192 bytes. Probability of drop can be
programmed on a 12.5 percent granularity. For
example, if bit 0 is set the first packet out of every eight
will be dropped in this region. (Default=0)
red-dv8to10k 0 to 255 Random early detection and packet drop vectors for
when FIFO threshold is greater than 8,192 bytes and
less than 10,240 bytes. Probability of drop can be
programmed on a 12.5 percent granularity. For
example, if bit 1 and 6 are set the second and seventh
packets out of every eight will be dropped in this
region. (Default=0)
red-dv10to12k 0 to 255 Random early detection and packet drop vectors for
when FIFO threshold is greater than 10,240 bytes and
less than 12,288 bytes. Probability of drop can be
programmed on a 12.5 percent granularity. If bit 2, 4
and 6 are set then the third, fifth and seventh packets
out of every eight will be dropped in this region.
(Default=0)