Modifying The Window Size And Scaling Factor; Tcp Window Size And Scaling Factor Recommendations; Tcp Window Size Scale Factors; T1/Ds-1 1.554 Mb/Sec (Bandwidth = 1 Mb) - HP StorageWorks MPX200 User Manual

Modifying the window size and scaling factor

The MPX200 window size can be set to a maximum of 32 KB. The scaling factor is used as a multiplier
to increase the window size above 32 KB. Modify the window size and scaling factor in the MPX200
Multifunction Router pairs based on the WAN RTT and link speed. To determine the appropriate
window size setting and scaling factor, use the pre-populated tables or the following formula.
If the recommended TCP window size and scale factor for a given RTT and WAN link speed is not
shown in Table 19
byte/8 bits)) = minimum window size (MWS).
Then, convert the MWS to a recommended scale factor by dividing it by the default window size
(32,768 bytes). Use
Table 18 TCP window size scale factors
MVS scale result
0 to 2
2 to 4
4 to 8
8 to 16
16 to 32
32 to 64
64 to 128
128 to 256
256 to 512
512 or greater

TCP window size and scaling factor recommendations

Table 19 through
environments. These tables are organized by typical link speed.
NOTE:
The TCP window size recommendations listed in
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 19 T1/DS-1 1.554 Mb/Sec (Bandwidth = 1 Mb)
Round trip time (RTT) in ms
250
134 MPX200 FCIP
through Table 25, use the formula: (RTT (ms) x link rate (Kb/s) x (1
Table 18 to determine the scale factor.
Table 25 provide TCP window size and scaling factor settings for specific WAN
Window size (bytes)
64K
Scale factor
0
1
2
3
4
5
6
7
8
9
Table 19 through Table 25
Scaling factor (2
1
are based on low-loss
n
)