2. Page 2
Why QoS – Transport Problems of the IP Network
The transport on an IP network has the following features:
Light load: better service quality on the network
Heavy load: packet delay and packet loss
IP network
1. IP packets delayed
2. IP packets lost
3. IP packets dropped
3. Page 3
Packet Loss
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Jack
am ……
What is said on the local…
I Wilson
am ……
What is heard on the opposite…
?
7. Page 7
What is QoS?
Quality of service (QoS) indicates the expected service class in terms of
packet loss, delay, delay variation, and bandwidth during network
communication. QoS ensures that request and response of a user or
application correspond to a certain predictable service class.
In the case of Internet, QoS indicates the packet forwarding capability of
the network. As there is a large variety of services on the network, the
QoS assessment can be based on different aspects.
8. Page 8
QoS Deployment Flow
Traffic
Classify
All the Qos
activities
perform after
the traffic
classification
Traffic
policing
Can monitor,
manage and
use the
limitation
resource, avoid
the burst
Marking and
Remarking
Regard of the
service level,
provide different
service quality
Congestion
avoidance
Can control
network traffic
flow in
advance,
mitigate the
congestion
Traffic
Shapping
Initiative
adjustment, let
service flow
transmit
smoothly