Qos Configuration - Planet VC-820M User Manual

4.15.2 QoS Configuration

QoS settings allow customization of packet priority in order to facilitate delivery of data traffic that might be affected by
latency problems. When CoS / 802.1p Tag Priority is applied, the Switch recognizes 802.1Q VLAN tag packets and extracts
the VLAN tagged packets with User Priority value.
802.1Q Tag and 802.1p priority
TPID (Tag Protocol Identifier)
Destination
Preamble
Address
6 bytes
Set up the COS priority level. With the drop-down selection item of Priority Type above being selected as COS only/COS
first, this control item will then be available to set the queuing policy for each port.
4.15.2.1 Priority Queue Service settings
QoS settings allow customization of packet priority in order to facilitate delivery of data traffic that might be affected by
latency problems. The IEEE 802.1p Priority specification uses 8 priority levels to classify data packets. In 802.1p compliant
devices, a tag inserted into the packet header is used to identify the priority level of data packets.
The Switch supports Static Port Ingress priority and four queues.
User Priority
3 bits 1 bits
TCI (Tag Control Information)
2 bytes
Source
VLAN TAG
Address
6 bytes 4 bytes
Figure 4-15-1: 802.1p Tag Priority
Figure 4-15-2: QoS Configuration – 802.1Priority
CFI VLAN ID (VID)
12 bits
2 bytes
Ethernet
Data
Type
2 bytes 46-1500 bytes
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User's Manual of VC-820M
FCS
4 bytes