Configuring Vlans; Understanding Ieee 802.1P Priority - D-Link DGS-3324SRi User Manual

D-Link DGS-3324SRi Intelligent Stackable Gigabit Ethernet Switch
The following parameters can be set:
Parameter
VID
Multicast MAC
Address
Port Settings

Configuring VLANs

Understanding IEEE 802.1p Priority

Priority tagging is a function defined by the IEEE 802.1p standard designed to provide a means of managing
traffic on a network where many different types of data may be transmitted simultaneously. It is intended to
alleviate problems associated with the delivery of time critical data over congested networks. The quality of
applications that are dependent on such time critical data, such as video conferencing, can be severely and
adversely affected by even very small delays in transmission.
Network devices that are in compliance with the IEEE 802.1p standard have the ability to recognize the priority
level of data packets. These devices can also assign a priority label or tag to packets. Compliant devices can also
strip priority tags from packets. This priority tag determines the packet's degree of expeditiousness and
determines the queue to which it will be assigned.
Priority tags are given values from 0 to 7 with 0 being assigned to the lowest priority data and 7 assigned to the
highest. The highest priority tag, 7, is generally only used for data associated with video or audio applications,
which are sensitive to even slight delays, or for data from specified end users whose data transmissions warrant
special consideration.
The Switch allows you to further tailor how priority tagged data packets are handled on your network. Using
queues to manage priority tagged data allows you to specify its relative priority to suit the needs of your network.
There may be circumstances where it would be advantageous to group two or more differently tagged packets
into the same queue. Generally, however, it is recommended that the highest priority queue, Queue 0, be
reserved for data packets with a priority value of 7. Packets that have not been given any priority value are
placed in Queue 6 and thus given the lowest priority for delivery.
Figure 4- 16. Setup Static Multicast Forwarding Table
Description
The VLAN ID of the VLAN the above MAC address belongs to.
The MAC address of the static source of multicast packets. This must be a
multicast MAC address.
None – The port is not a member of the Static Multicast Group.
Egress – the port is a static member of the multicast group.
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