Installation guide

3 – Planning
Performance Tuning
3-4 SN0051102-00 A
S
Distance
Consider the physical distance between routers. This is usually measured in
round-trip delay. Round-trip delay ranges anywhere from less than 1 ms to as
great as 250 ms.
Performance Tuning
Properly configuring the router maximizes its performance. Knowing the round-trip
delay (distance) between routers and the WAN effective data rate (connection
type) allows you to tune the routers for optimal performance. The following tables
provide TCP Window Scaling Factor and Window Size settings for specific
WAN environments.
NOTE:
For high loss networks, QLogic recommends decreasing the TCP Window
Size from the initial recommended setting until the network achieves optimal
performance.
Table 3-1. T1 / DS-1 – 1.554 Mbits/Sec
Round Trip delay
(ms)
Total Window Size
(bytes)
Scaling Factor
250 64 K 1
100 32 K 0
50 32 K 0
25 32 K 0
20 32 K 0
15 32 K 0
10 32 K 0
5 32 K 0
2.5 32 K 0
1 or less 32 K 0