Qlogic QLogic Fibre Channel Switch Guia de Instalação descarregar pdf (Página 40)

3 – Planning

Performance

3-4 59055-00 B

3.3

Performance

The SANbox 5200 switch supports class 2 and class 3 Fibre Channel service at

transmission rates of 1 Gbps, 2 Gbps, or 10 Gbps with a maximum frame size of

2148 bytes. A 1Gbps/2Gbps port can transmit or receive at 1 Gbps or 2 Gbps

depending on the device to which it is connected. The port discovers the

transmission speed prior to login when the connected device powers up. 10 Gbps

ports transmit at 10 Gbps. Related performance characteristics include the

following:

 Distance

 Bandwidth

 Latency

3.3.1

Distance

Consider the physical distribution of devices and switches in the fabric. Choose

SFP transceivers that are compatible with the cable type, distance, Fibre Channel

revision level, and the device host bus adapter. Refer to

Appendix A Specifications for more information about cable types and

transceivers.

Each 1Gbps/2Gbps and 10 Gbps port is supported by a data buffer with a 16

credit capacity; that is, 16 maximum sized frames. For fibre optic cables, this

enables full bandwidth over a distance of 26 kilometers at 1 Gbps (0.6

credits/Km), or 13 kilometers at 2 Gbps (1.2 credits/Km). Beyond this distance,

however, there is some loss of efficiency because the transmitting port must wait

for an acknowledgement before sending the next frame.

Longer distances can be spanned at full bandwidth on 1Gbps/2Gbps ports by

extending credits to G_Ports, F_Ports, and E_Ports. Each port can donate 15

credits to a pool from which a recipient port can borrow. However, 1Gbps/2Gbps

ports can borrow only from other 1Gbps/2Gbps ports. 10 Gbps ports cannot

borrow or donate credits. The reciepient port also loses a credit in the process.

For example, you can configure a 1Gbps/2Gbps recipient port to borrow 15 credits

from one donor port for a total of 30 credits (15+15=30). This will support

communication over approximately 50 Km at 1 Gbps (31÷0.6) or 25 Km at 2 Gbps

(30÷1.2).

You can configure recipient and donor ports using the SANbox Manager

application or the Set Config command. Refer to ”Set Config Command” on

page B-33 for more information.

1 2 ... 35 36 37 38 39 40 41 42 43 44 45 ... 205 206

Sem comentários

Qlogic QLogic Fibre Channel Switch Guia de Instalação Página 40