HP MPX200 Multifunction Router - Manual (Page 124)

Then, convert the MWS to a recommended scale factor by dividing it by the default window size
(32,768 bytes). Use
Table 21 (page 124) to determine the scale factor.
Table 21 TCP window size scale factors
Scale factor / TCP Window size MWS scale result
0 / 32KB 0 to 2
1 / 64KB 2 to 4
2 / 128KB 4 to 8
3 / 256KB 8 to 16
4 / 512KB 16 to 32
5 / 1MB 32 to 64
6 / 2MB 64 to 128
7 / 4MB 128 to 256
8 / 8MB 256 to 512
9 / 16MB 512 or greater
TCP window size and scaling factor recommendations
Table 22 (page 124) through Table 28 (page 126) provide TCP window size and scaling factor
settings for specific WAN environments. These tables are organized by typical link speed.
NOTE: The TCP window size recommendations listed in Table 22 (page 124) through
Table 28 (page 126) are based on low-loss networks (0.0012% average packet-loss ratio over 24
hours). For higher-loss, longer-latency networks, you should reduce the recommended window size
and scaling factor by one setting to compensate for the increased number of packet retransmissions.
Table 22 T1/DS-1 1.554 Mb/sec (bandwidth = 1 Mb)
Scaling factor (2
n
) Window size (bytes) Round trip time (RTT) in ms
1 64K 250
0 32K 100
0 32K 50
0 32K 25
0 32K 20
0 32K 15
0 32K 10
0 32K 5
0 32K 2.5
0 32K 1 or less
Table 23 T3/DS-3 45 Mb/sec (bandwidth = 43 Mb)
Scaling factor (2
n
) Window size (bytes) Round trip time (RTT) in ms
5 1M 250
4 512K 100
3 256K 50
124 MPX200 FCIP