Planet Networking & Communication WGSW-48000, Руководство пользователя

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User’s Manual of WGSW-48000
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4.8.3 802.1P
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 Managed Switch recognizes 802.1Q VLAN tag packets and extracts
the VLAN tagged packets with User Priority value.
„ 802.1Q Tag and 802.1p priority
User Priority CFI VLAN ID (VID)
3 bits 1 bits 12 bits
TPID (Tag Protocol
Identifier)
TCI (Tag Control
Information)
2 bytes 2 bytes
Preamble
Destination
Address
Source
Address
VLAN TAG
Ethernet
Type
Data FCS
6 bytes 6 bytes 4 bytes 2 bytes 46-1517 bytes 4 bytes
Figure 4-8-7: 802.1p Tag Priority
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.
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 Managed Switch supports Port-based QoS (Port priority mapping) and four queues . The screen in Figure 4-8-8 appears .
802.1P sets the priority relationships between queues and 802.1p priority.