Bandwidth; Extended Credit Distances And Cable Lengths - Qlogic SANbox 5600 Series Installation Manual

3 – Planning
Performance
Regardless of how many credits are borrowed, extending credits requires a
minimum cable length that is dependent on transmission speed. Extending credits
over short cables can cause excessive port resets.
possible distances and minimum cable lengths for a port with 30 credits.
Transmission Speed
1-Gbps
2-Gbps
4-Gbps

Bandwidth

Bandwidth is a measure of the volume of data that can be transmitted at a given
transmission rate. An SFP port can transmit or receive at nominal rates of 1-, 2-,
or 4-Gbps depending on the device to which it is connected. This corresponds to
full duplex bandwidth values of 212 MB, 424 MB, and 850 MB respectively. XPAK
ports transmit at a nominal rate of 10-Gbps which corresponds to a full duplex
bandwidth value of 2550 MB.
In multiple chassis fabrics, each link between chassis contributes 424, 850, 1700,
or 2550 megabytes of bandwidth between those chassis, depending on the speed
of the link. When additional bandwidth is needed between devices, increase the
number of links between the connecting switches. The switch guarantees in-order
delivery with any number of links between chassis.
3-4
Table 3-2. Extended Credit Distances and Cable Lengths
Range for 30 Credits
Table 3-2
50 Km (30÷0.6)
25 Km (30÷1.2)
12 Km (30÷2.4)
S
describes the
Minimum Cable Length
3 Km
1.5 Km
0.75 Km
59096-06 A