Alcatel-Lucent 7450 Quality Of Service Manual page 203

CE UNI
Access
Device
The following shows an example of the QoS processing in more detail.
Figure 16
Case for both ingress and egress directions (from a PE1 SAP perspective).
1
Access
Device
The following steps related to DEI are involved in the QoS processing as the packet moves
from left to right:
Quality of Service Guide
Figure 15: DE Aware 802.1ad Access Network
802.1 a/d
Access
SAP
(DE aware)
displays a simple example of the DEI processing steps for the IEEE 802.1ad Use
Figure 16: DEI Processing Ingress into the PE1 SAP
7x50 PE1
802.1 a/d
Access
2
(DE aware)
SAP Ingress
1. The QinQ access device sets the DE bit from the STAG based on the QoS
classification or on the results of the metering/policing for the corresponding
customer UNI.
2. The SAP on PE1 may use the DE bit from the customer STAG to classify the frames
as in/out of profile. Color aware policing/metering can generate addition out of
profile packets as the result of packet flow surpassing the CIR.
3. When the packet leaves PE1 via SDP, the DE indication must be copied onto the
appropriate tunnel QoS fields (outer VLAN ID and or EXP bits) using the internal
PHB (per hop behavior) of the packet (for example, the FC and Profile).
4. As the packet arrives at PE2, ingress into the related SDP, the DE indication is used
to classify the packets into an internal PHB.
5. Egress from the PE2 SAP, the internal PHB may be used to perform marking of the
DE bit.
Service Egress and Ingress QoS Policies
7x50 PE1
MPLS
SDP
MPLS
3
SDP Egress SDP Egress
7x50 PE2
SDP I-SAP
7x50 PE2
4 5
SAP Egress
CE
203