Q-Logic 6140 manual Performance Tuning, T1 / DS-1 1.554 Mbits/Sec, T3 / DS-3 45 Mbits/Sec

3 – Planning Performance Tuning

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Performance Tuning

Proper configuration maximizes the router’s performance. Knowing the round trip delay (distance between the router and iSCSI initiators) and WAN effective data rate (connection type) allows you to tune the router for optimal performance. The following tables provide TCP Window Size settings for specific WAN environments. The TCP Window Size is configured as two parameters: Window Size and Scaling Factor. See page 7-28and page A-33for configuring the TCP window size.

Table 3-1. T1 / DS-1: 1.554 Mbits/Sec

Round Trip		TCP Window	SANbox 6140	SANbox 6140
Delay (ms)		Size (bytes)	Window Size	Scaling
				Factor
250		64 K	32K	1
100		32 K	32K	0
50		32 K	32K	0
25		32 K	32K	0
20		32 K	32K	0
15		32 K	32K	0
10		32 K	32K	0
5		32 K	32K	0
2.5		32 K	32K	0
1 or less		32 K	32K	0
	Table 3-2. T3 / DS-3: 45 Mbits/Sec
Round Trip		TCP Window	SANbox 6140	SANbox 6140
Delay (ms)		Size (bytes)	Window Size	Scaling
				Factor
250		1 MB	32K	5
100		512 K	32K	4
50		256 K	32K	3
25		128 K	32K	2
20		128 K	32K	2

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