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.