GE GE-DS-242-POE, Руководство пользователя

Страница: 160 / 210

Chapter 6: Command Line Interface
156 GE-DS-242-PoE Managed Ethernet Switch User Manual
Quality of Service
There are four transmission queues with different priorities in the Managed Switch:
Highest, SecHigh, SecLow and Lowest. The Managed Switch will take packets from
the four queues according to its QoS mode setting. If the QoS mode was set to
"Disable", the Managed Switch will not perform QoS on its switched network. If the
QoS mode was set to "High Empty Then Low", the Managed Switch will never exhaust
packets from a queue until the queues with higher priorities are empty. If the QoS
mode was set to "weight ratio", the Managed Switch will exhaust packets from the
queues according to the ratio. The default value of QoS mode is "weight 8:4:2:1." That
means the switch will first exhaust 8 packets from the queue with highest priority,
and then exhaust 4 packets from the queue with second high priority, and so on.
When the switch received a packet, the switch has to decide which queue to put the
received packet into. In the Managed Switch, it will put received packets into queues
according to the settings of "802.1p Priority" and "Static Port Ingress Priority." When
the received packet is an 802.1p tagged packet, the switch will put the packet into a
queue according to the 802.1p Priority setting.
Otherwise, the switch will put the packet into a queue according the setting of Static
Port Ingress Priority.
•
802.1p Priority: the 802.1p packet has a priority tag in its packet header. The
range of the priority is 7~0. The Managed Switch can specify the mapping
between 802.1p priority and the four transmission queues. In the default setting,
the packets with 802.1p priority 0~1 are put into the queue with lowest priority,
the packets with 802.1p priority 2~3 are put into queue with second low priority,
and so on.
•
Static Port Ingress Priority: each port is assigned with one priority 7~0. The priority
of the packet received from one port is set to the same priority of the receiving
port. When the priority of the received packet was determined, the packet is
treated as an 802.1p packet with that priority and will be put into a queue
according to the 802.1p Priority setting.
QoS Configuration
QoS mode:
•
First Come First Service: The sequence of packets sent is depending on arrive
orders.
•
All High before Low: The high priority packets sent before low priority packets.
•
WRR: Weighted Round Robin. Select the preference given to packets in the
switch's high-priority queue. These options represent the number of higher