At 09:21 AM 9/10/2002 +0800, Jason Gao wrote:
>I mean it did not prohibit the use of one bit in the traffic class octet
>for control purpose.
actually, it very explicitly did. At the top of page 8, it says:
Implementors should note that the DSCP field is six bits wide. DS-
compliant nodes MUST select PHBs by matching against the entire 6-bit
DSCP field, e.g., by treating the value of the field as a table index
which is used to select a particular packet handling mechanism which
has been implemented in that device.
The other two bits are defined by RFC 3168.
You don't get to pull a bit out for your private use.