3-2
IP Precedence (decimal) IP Precedence (binary) Description
6 110 internet
7 111 network
In a network providing differentiated services, traffics are grouped into the following four classes, and
packets are processed according to their DSCP values.
z Expedited Forwarding (EF) class: In this class, packets can be forwarded regardless of link share
of other traffic. The class is suitable for preferential services with low delay, low packet loss ratio,
low jitter, and assured bandwidth (such as virtual leased line);
z Assured forwarding (AF) class: This class is further divided into four subclasses (AF1/2/3/4) and a
subclass is further divided into three drop priorities, so the AF service level can be segmented. The
QoS rank of the AF class is lower than that of the EF class;
z Class selector (CS) class: This class comes from the IP ToS field and includes eight subclasses;
z Best Effort (BE) class: This class is a special class without any assurance in the CS class. The AF
class can be degraded to the BE class if it exceeds the limit. Current IP network traffic belongs to
this class by default.
Table 3-2 Description on DSCP precedence values
DSCP value (decimal) DSCP value (binary) Description
46 101110 ef
10 001010 af11
12 001100 af12
14 001110 af13
18 010010 af21
20 010100 af22
22 010110 af23
26 011010 af31
28 011100 af32
30 011110 af33
34 100010 af41
36 100100 af42
38 100110 af43
8 001000 cs1
16 010000 cs2
24 011000 cs3
32 100000 cs4
40 101000 cs5
48 110000 cs6
To Next Page
Loading...
Need help?
General