Vigor2920 Series User’s Guide
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To activate the function of limit bandwidth, simply click
Enable
and set the default upstream
and downstream limit.
Enable
Click this button to activate the function of limit bandwidth.
Apply to 2
nd
Subnet
–
Check this box to apply the bandwidth
limit to the second subnet specified in
LAN>>General Setup
.
Disable
Click this button to close the function of limit bandwidth.
Default TX limit
Define the default speed of the upstream for each computer in
LAN.
Default RX limit
Define the default speed of the downstream for each computer
in LAN.
Limitation List
Display a list of specific limitations that you set on this web
page.
Start IP
Define the start IP address for limit bandwidth.
End IP
Define the end IP address for limit bandwidth.
TX limit
Define the limitation for the speed of the upstream. If you do
not set the limit in this field, the system will use the default
speed for the specific limitation you set for each index.
RX limit
Define the limitation for the speed of the downstream. If you do
not set the limit in this field, the system will use the default
speed for the specific limitation you set for each index.
Add
Add the specific speed limitation onto the list above.
Edit
Allows you to edit the settings for the selected limitation.
Delete
Remove the selected settings existing on the limitation list.
Index (1-15) in Schedule
Setup
You can type in four sets of time schedule for your request.
All the schedules can be set previously in
Application >>
Schedule
web page and you can use the number that you have
set in that web page.
4.7.3 Quality of Service
Deploying QoS (Quality of Service) management to guarantee that all applications receive the
service levels required and sufficient bandwidth to meet performance expectations is indeed
one important aspect of modern enterprise network.
One reason for QoS is that numerous TCP-based applications tend to continually increase their
transmission rate and consume all available bandwidth, which is called TCP slow start. If
other applications are not protected by QoS, it will detract much from their performance in the
overcrowded network. This is especially essential to those are low tolerant of loss, delay or
jitter (delay variation).
Another reason is due to congestions at network intersections where speeds of interconnected
circuits mismatch or traffic aggregates, packets will queue up and traffic can be throttled back
to a lower speed. If there’s no defined priority to specify which packets should be discarded
(or in another term “dropped”) from an overflowing queue, packets of sensitive applications
mentioned above might be the ones to drop off. How this will affect application performance?
There are two components within Primary configuration of QoS deployment:
z
Classification: Identifying low-latency or crucial applications and marking them for
high-priority service level enforcement throughout the network.
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