|
In the legacy network shown in the Figure,
accounting users on the two segments have to cross the engineering
segment to transfer any data. The frames have to pass through two
routers. Software-based routers tend to be slower than other
internetworking products such as a Layer 2 bridge or switch. As a frame passes through a router, the router introduces latency to the network. Latency constitutes the amount of time necessary to transport a frame from the source port to the destination port.
Every router that the frame transits
increases the end-to-end latency. Further, every congested segment that
a frame must cross increases latency.
By moving all the accounting users into
one VLAN, the need to cross through multiple routers and segments is
eliminated. This reduces latency in a network that will improve
performance for your users, especially if they use a send-acknowledge
protocol such as TCP. Send-acknowledge protocols do not send more data
until an acknowledgement is received referencing the previous data.
Network latency dramatically reduces the effective throughput for
send-acknowledge protocols. If you can eliminate the need for user
traffic to pass through a router by placing users in the same VLAN, you
can eliminate cumulative router latency. If frames must pass through
routers, enabling Layer 3 switching will significantly reduce router
transit latencies as well.
|
|