The DE bit is set to 0 for in-profile traffic and 1 for out-of-profile and exceed-profile traffic,
unless explicitly forced.
The precedence of the above commands is summarized as, from highest to lowest
precedence:
The configuration of qinq-mark-top-only under the SAP egress takes precedence over the use
of the de-mark-inner in the policy, i.e. the inner VLAN tag is not remarked when qinq-mark-
top-only is configured (the marking used for the inner VLAN tag is based on the current
default which is governed by the marking of the packet received at the ingress to the system).
If qinq-mark-top-only is omitted, both the inner and outer VLAN tags are remarked.
Remarking the inner DE bit is not supported based on the profile result of egress policing.
The egress remarking occurs after any egress classification.
DEI in IEEE 802.1ad
IEEE 802.1ad-2005 standard allows drop eligibility to be conveyed separately from priority
in service VLAN TAGs (STAGs). The service VLAN TAG has a new format where the
priority and discard eligibility parameters are conveyed in the three bit priority code point
(PCP) field and respectively in the DE bit
Octets
1
Bits
8
Quality of Service Guide
fc <fc-name> create
exit
exit
•
de-mark-outer used for outer tag markings
•
de-mark-inner used for inner tag markings
•
existing de-mark used for marking both tags
•
markings taken from packet received at ingress
Figure 14: DE Bit in the 802.1ad S-TAG
PCP
DE
6
5
4
Service Egress and Ingress QoS Policies
de-mark [force <de-value>]
de-mark-inner [force <de-value>]
de-mark-outer [force <de-value>]
(Figure
14).
2
VID
1
8
1
OSSG267
201