User guide

EDA System Services
1/1551-HSC 901 35/3 Uen C 2005-12-02
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2. PVC Mapping
The Service of the packets is identified and the packets are sent towards
the packet queuing of the designated PVC.
3. Packet Based Queuing
The packet based queuing enables treating different traffic contents on the
same PVC by transmitting high priority traffic before lower priority traffic.
This is done in three steps:
1 Sorting the packets in up to four different queues (a queue for each
CoS flow) according to their classification.
2 Applying policing on each CoS flow (optional)
3 Emptying the queues by sending the packets according to a schedule
that defines how these queues are emptied.
Figure 43 on page 60 illustrates the packets based queuing principle with
an End-user that has two services (on two PVCs). One service contains
only one CoS flow. That is, there is only one QoS definition for all the traffic
in that service. The other service contains four CoS flows. Frames in this
service will be treated according to their classification. That means that
higher priority frames will be sent by the traffic scheduler before lower
priority frames (according to the scheduler algorithm) for further processing.
Prioritizing between the two services after the packet based queuing, is
done in the ATM prioritization, according to the ATM Class of Service of
each PVC.