System information

2-67
Class of Service Configuration
2
Mapping IP Precedence
The Type of Service (ToS) octet in the IPv4 header includes three precedence bits
defining eight different priority levels ranging from highest priority for network control
packets to lowest priority for routine traffic. The default IP Precedence values are
mapped one-to-one to Class of Service values (i.e., Precedence value 0 maps to
CoS value 0, and so forth). Bits 6 and 7 are used for network control, and the other
bits for various application types. ToS bits are defined in the following table.
Command Attributes
• IP Precedence Priority Table – Shows the IP Precedence to CoS map.
• Class of Service Value – Maps a CoS value to the selected IP Precedence value.
Note that “0” represents low priority and “7” represent high priority.
Note: IP Precedence settings apply to all interfaces.
Table 2-5. Mapping IP Precedence
Priority Level Traffic Type
7 Network Control
6 Internetwork Control
5Critical
4 Flash Override
3Flash
2 Immediate
1Priority
0Routine