Bandwidth Control - D-Link DXS-3326GSR Manual

The picture above shows the default priority setting for the Switch. Class-6 has the highest priority of the eight priority
queues on the Switch. In order to implement QoS, the user is required to instruct the Switch to examine the header of a
packet to see if it has the proper identifying tag tagged. Then the user may forward these tagged packets to designated
queues on the Switch where they will be emptied, based on priority.
For example, lets say a user wishes to have a video conference between two remotely set computers. The administrator can
add priority tags to the video packets being sent out, utilizing the Access Profile commands. Then, on the receiving end,
the administrator instructs the Switch to examine packets for this tag, acquires the tagged packets and maps them to a class
queue on the Switch. Then in turn, the administrator will set a priority for this queue so that will be emptied before any
other packet is forwarded. This results in the end user receiving all packets sent as quickly as possible, thus prioritizing the
queue and allowing for an uninterrupted stream of packets, which optimizes the use of bandwidth available for the video
conference.
Understanding QoS
The Switch has seven classes of service. These classes of services are labeled as 6, the highest class, to 0, the lowest class.
The eight priority tags, specified in IEEE 802.1p are mapped to the Switch's classes of service as follows:
Priority 0 is assigned to the Switch's Q2 queue.
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Priority 1 is assigned to the Switch's Q0 queue.
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Priority 2 is assigned to the Switch's Q1 queue.
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Priority 3 is assigned to the Switch's Q3 queue.
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Priority 4 is assigned to the Switch's Q4 queue.
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Priority 5 is assigned to the Switch's Q5 queue.
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Priority 6 is assigned to the Switch's Q6 queue.
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Priority 7 is assigned to the Switch's Q6 queue.
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For strict priority-based scheduling, any packets residing in the higher priority queues are transmitted first. Multiple strict
classes of service are emptied based on their priority tags. Only when these queues are empty, are packets of lower priority
transmitted.
For weighted round-robin queuing, the number of packets sent from each class of service depends upon the assigned
weight. For a configuration of eight CoS queues, A~H with their respective weight value: 8~1, the packets are sent in the
following sequence: A1, B1, C1, D1, E1, F1, G1, H1, A2, B2, C2, D2, E2, F2, G2, A3, B3, C3, D3, E3, F3, A4, B4, C4,
D4, E4, A5, B5, C5, D5, A6, B6, C6, A7, B7, A8, A1, B1, C1, D1, E1, F1, G1, H1.
For weighted round-robin queuing, if each CoS queue has the same weight value, then each CoS queue has an equal
opportunity to send packets just like round-robin queuing.
For weighted round-robin queuing, if the weight for a CoS is set to 0, then it will continue processing the packets from this
CoS until there are no more packets for this CoS. The other CoS queues that have been given a nonzero value, and
depending upon the weight, will follow a common weighted round-robin scheme.
Remember that the DXS-3326GSR has seven classes of service for each port on the Switch.

Bandwidth Control

The bandwidth control settings are used to place a ceiling on the transmitting and receiving data rates for any selected port.
In the Configuration folder, click Port Bandwidth, to view the window shown below.
DXS-3326GSR Gigabit Layer 3 Switch
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