LevelOne FGP-1072, User Manual

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3-22. QoS(Quality of Service) Configuration
The switch supports QoS, are as follows, 802.1p Priority and DiffServ DSCP
Priority. VLAN tagged Priority field is effected by 802.1p Priority setting. DiffServ
DSCP Priority act on DSCP field of IP Header. In the late 1990s, the IETF redefined
the meaning of the 8-bit SERVICE TYPE field to accommodate a set of
differentiated services (DS). Under the differentiated services interpretation, the first
six bits comprise a codepoint, which is sometimes abbreviated DSCP, and the last
two bits are left unused.
High Priority Packet streams will experience less delay into the switch. For
handing different priority packets, each egress port has designed up to 4 queues.
Each QoS is influenced by two scheduling, WRR (Weighted Round Robin) and
Strict Priority as well. When you finish to set the priority mapping to the queue, WRR
scheduling will distribute the bandwidth according to the weight you set for 4 queues
(queue 0 to queue 3). Another scheduling is Strict Priority dedicated for the function
named VIP Port of QoS. While we select some ports as the VIP Port, these ports
will own the highest transmitting priority in egress queue of the switch.
Function name:
QoS Global Setting
Function description:
When you want to use QoS function, please enable QoS Mode in advance.
Then you can use 802.1p Priority and DiffServ DSCP Priority functions and
take effect. In this function, you can Enable QoS Mode. Choose any of Priority
Control, such as 802.1p and DSCP. Moreover, you can select Scheduling
Method of WRR (Weighted Round Robin) or Strict Priority. Next, you can
arrange Weight values for queue 0 to queue 3.
Fig. 3-84
Parameter description:
QoS Mode: