Protocol Priority; Traffic Policing And Traffic Shaping - 3Com 4200G 12-Port Configuration Manual

Table 1-6 The default CoS-precedence-to-other-precedence mapping table of Switch 4200G series
802.1p precedence value
0
1
2
3
4
5
6
7
Table 1-7 The default DSCP -to-other-precedence mapping table of Switch 4200G series
DSCP values
0 to 7
8 to 15
16 to 23
24 to 31
32 to 39
40 to 47
48 to 55
56 to 63

Protocol Priority

Protocol packets generated by your switch carry their own priority. You can set a new IP precedence or
DSCP value for the locally generated traffic of a particular protocol to implement QoS.

Traffic Policing and Traffic Shaping

If user traffic is not limited, burst traffic will make your network more congested. To better utilize the
network resources and provide better services for more users, you must take actions to control user
traffic. For example, you can configure a flow to use only the resources committed to it in a time range,
thus avoiding network congestion caused by burst traffic.
Traffic policing and traffic shaping limit traffic rate and resource usage according to traffic specifications.
The prerequisite for traffic policing or traffic shaping is to know whether a traffic flow has exceeded the
specification. If yes, proper traffic control policies are applied. Generally, token buckets are used to
evaluate traffic specifications.
Target local precedence
value
2
0
1
3
4
5
6
7
Target local precedence
value
0
1
2
3
4
5
6
7
1-8
Target drop precedence value
0
0
0
0
0
0
0
0
Target drop precedence value
1
1
1
1
0
0
0
0