3Com 8800 Configuration Manual page 393

3Com Switch 8800 Configuration Guide
Configuring Traffic Shaping
Configuring Traffic Priority
Configuring Traffic Redirection
Configuring Queue Scheduling
Configuring Traffic Mirroring
Configuring Port Mirroring
Configuring Traffic Statistics
Before initiating any of these QoS configuration tasks, you should first define the
corresponding ACL. Then you can achieve packet filtering just by activating the right
ACL.
To configure packet filtering, you need only to activate corresponding ACL. For more
details, refer to the section 32.2.4 .
Some of QoS terms are listed in the following table.
Table 33-2 QoS terms
Term
CoS
Service
parameters
Drop-precedence
Conform-Level
33.3.1 Configuring Service Parameter Allocation Rule
QoS is based on service parameters, a set of parameters for a packet, including 802.1p
priority (CoS priority), DSCP priority, EXP priority, local precedence and drop
precedence.
It has the same meaning as 802.1p priority. Both refer to the
priority at packet header, with the value ranging from 0 to 7.
Switch allocates a set of parameters, which are used in
achieving QoS functions, upon receiving a packet. Four items
are included: 802.1p priority, DSCP priority, local precedence
and drop precedence.
One of service parameters, ranging from 0 to 2. Drop
precedence is allocated when the switch receives the packet
and may be when the packet is processed. Allocating drop
precedence to the packet is also called coloring the packet: the
packet with drop precedence 2 as red, that with drop
precedence 1 as yellow and that with drop precedence 0 as
green. Drop precedence is referred to when switch needs to
drop packets in its congestion.
The result calculated from the user-defined CIR, CBS, EBS,
PIR and actual traffic when the switch runs traffic policing, in the
range of 0 to 2. It is used as a parameter in the traffic-limit
command (here the value depends on the calculated result). It
is also involved in the DSCP + Conform level —> Service
parameter mapping table which is used in re-allocating service
parameters to a packet with the traffic-priority command.
Then Conform-Level must be 0.
33-9
Chapter 33 QoS Configuration
Description