User guide

EDA System Services
58 1/1551-HSC 901 35/3 Uen C 2005-12-02
Ethernet
Service
VLAN
Service
VLAN
Service
VLAN
PVCs
PVC
mapping
Packet
based
queuing
Packet
based
queuing
Packet
based
queuing
ATM
prioritization
IP DSLAM
PVCs
Packet
based
queuing
Packet
based
queuing
ATM
prioritization
Traffic
IP
DSLAM
overload
protection
Figure 42 Downstream QoS Mechanisms
The traffic from the Ethernet will go through the following processes:
1. Overload Protection
The overload protection is only in use if there is more than one packet
waiting to be processed. There are four queues in the IP DSLAM
downstream overload protection. They correspond to the following
classification classes:
Table 5 Overload Protection Queues
Queue Priority Classification Class
1 Highest 7
2 High 6
3 Medium 5
4 Low 0 - 4
Note the same four queues are used for all traffic coming from the Ethernet.
Strict priority is used in the scheduling of the overload protection.