Q-Logic 6140 manual ISCSI Performance, Bandwidth, Latency

A

3 – Planning iSCSI Performance

Beyond these distances, however, the connection loses some efficiency because the transmitting port must wait for an acknowledgement before sending the next frame.

Bandwidth

Bandwidth is a measure of the volume of data that can be transmitted at a given transmission rate. A 1-Gbps/2-Gbps FC port can transmit or receive at nominal rates of 1- or 2-Gbps, depending on the device to which it is connected. This corresponds to actual bandwidth values of 106 MB and 212 MB, respectively.

Latency

Latency is a measure of how fast a transaction travels through the router.

iSCSI Performance

The SANbox 6140 router supports Ethernet service at transmission rates of 1000-, 100- or 10-Mbps with an MTU size of 1500 or 9000 (jumbo frames).

NOTE:

An MTU size greater than 1500 should only be used when the router is connected to a 1000 Mbps Ethernet network.

Related performance characteristics include the following:

„Latency

„Bandwidth

„Latency

Distance

Consider the physical distance between routers.This is usually measured in round-trip delay. Round trip delays ranges anywhere from less than 1 millisecond to as great as 250 milliseconds.

Bandwidth

Bandwidth is a measure of the volume of data that can be transmitted at a given transmission rate. WAN data rates range from 1.5 megabits per second (T1) to greater than 600 megabits per second (OC-12).

Latency

Latency is a measure of how fast a transaction travels through the router and LAN/WAN.

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