3com 3031 Instruccion De Instalación
67
T
RAFFIC
C
LASSIFICATION
, P
OLICING
,
AND
S
HAPING
This chapter tells you the following:
■
Introduction to Traffic Classification,
Policing and Shaping
■
How To Configure Traffic Policing and Traffic Shaping
■
Troubleshooting Traffic Policing and Traffic Shaping
■
Typical Example of Traffic Policing and Traffic Shaping
Introduction to Traffic
Classification
Classification
Traffic classification is the prerequisite and foundation for differentiated service,
which uses certain rules to identify the packets with certain features.
which uses certain rules to identify the packets with certain features.
Traffic classification rule can be set by using the priority bits of ToS (type of service)
field in IP packet header to identify the traffic having different preference features.
Or the network administrator may define a traffic classification policy, for instance,
integrating information such as source IP address, destination IP address, MAC
address, IP or port number of the applications to classify the traffic. In general, it
can be a narrow range defined by a quintuple (source IP address, source port
number, destination IP address, destination port number and the Transport
Protocol), or can be all packets to a network segment.
field in IP packet header to identify the traffic having different preference features.
Or the network administrator may define a traffic classification policy, for instance,
integrating information such as source IP address, destination IP address, MAC
address, IP or port number of the applications to classify the traffic. In general, it
can be a narrow range defined by a quintuple (source IP address, source port
number, destination IP address, destination port number and the Transport
Protocol), or can be all packets to a network segment.
In general, while packets being classified on the network border, the precedence
bits in the ToS byte of IP header are set so that IP precedence can be used as a
direct packet classification standard within the network. The queuing
technologies, such as WFQ, can use IP precedence to handle the packets.
Downstream network can receive the packets classification results from upstream
network selectively, or re-classify the packets with its own standard.
bits in the ToS byte of IP header are set so that IP precedence can be used as a
direct packet classification standard within the network. The queuing
technologies, such as WFQ, can use IP precedence to handle the packets.
Downstream network can receive the packets classification results from upstream
network selectively, or re-classify the packets with its own standard.
Traffic classification is used to provide differentiated service, so it must be
associated with certain kinds of traffic policing or resource-assignment
mechanisms. To adopt what kind of traffic policing action will depend on the
current stage and load status of the network. For example, to police the packets
according to the committed rate when they enter the network, to make traffic
shaping before they flow out of the nodes, to do queuing management in the
event of congestion and to employ congestion avoidance when congestion
becomes worse.
associated with certain kinds of traffic policing or resource-assignment
mechanisms. To adopt what kind of traffic policing action will depend on the
current stage and load status of the network. For example, to police the packets
according to the committed rate when they enter the network, to make traffic
shaping before they flow out of the nodes, to do queuing management in the
event of congestion and to employ congestion avoidance when congestion
becomes worse.
Traffic Policing and
Traffic Shaping
Traffic Shaping
If no restrictrictions are imposed on the traffic from users, bursting data sent
continuously by mass users will make the network congested. For more efficient
network function and a better network service for users, the traffic from users
must be restricted.
continuously by mass users will make the network congested. For more efficient
network function and a better network service for users, the traffic from users
must be restricted.