Network Load Control
UM Basic Configuration L3P
Release
7.1
12/2011
8.4
QoS/Priority
173
Assured Forwarding (AF): Provides a differentiated schema for
handling different data traffic (RFC 2597).
Default Forwarding/Best Effort: No particular prioritizing.
The PHB class selector assigns the 7 possible IP precedence values from
the old ToS field to specific DSCP values, thus ensuring the downwards
compatibility.
ToS Meaning Precedence Value Assigned DSCP
Network Control 111 CS7 (111000)
Internetwork Control 110 CS6 (110000)
Critical 101 CS5 (101000)
Flash Override 100 CS4 (100000)
Flash 011 CS3 (011000)
Immediate 010 CS2 (010000)
Priority 001 CS1 (001000)
Routine 000 CS0 (000000)
Table 15: Assigning the IP precedence values to the DSCP value