Compression; Tcp Window Size/Scaling Performance Tuning; Modifying The Window Size And Scaling Factor - HP StorageWorks 6100 - Enterprise Virtual Array User Manual

Compression

The mpx110 integrates a software compression option. Enable compression for IP fabrics with an RTT
greater than or equal to 50 ms, or guaranteed WAN bandwidth of less than or equal to 45 Mb/s.
See "TCP window size
rates and RTT.

TCP window size/scaling performance tuning

The mpx110 performance is maximized when properly configured. Knowing the RTT (distance)
between mpx110 gateways and the WAN effective data rate (connection type) allows the gateways
to be tuned for optimal performance. See

Modifying the window size and scaling factor

The mpx110 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 mpx110
gateway pairs based on the WAN RTT and link speed. To determine the appropriate window size
setting, use the pre-populated tables or a formula.
If the recommended TCP window size scale factor for a given RTT and WAN link speed is not shown
in Table 4 through
(RTT (ms) x link rate (Kb/s) x (1 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
32 Configuration rules and guidelines
recommendations" on page 34 for compression options for specific network
"Modifying the window size and scaling
Table 10, use the following formula:
Table 3 to determine the scale factor.
factor" on page 32.