ZyXEL Communications Plumbing Product metrogigabit switch User Manual
Chapter 36 Differentiated Services
MGS3700-12C User’s Guide
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The DSCP value determines the PHB (Per-Hop Behavior), that each packet gets as
it is forwarded across the DiffServ network. Based on the marking rule different
kinds of traffic can be marked for different priorities of forwarding. Resources can
then be allocated according to the DSCP values and the configured policies.
it is forwarded across the DiffServ network. Based on the marking rule different
kinds of traffic can be marked for different priorities of forwarding. Resources can
then be allocated according to the DSCP values and the configured policies.
36.1.2 DiffServ Network Example
The following figure depicts a DiffServ network consisting of a group of directly
connected DiffServ-compliant network devices. The boundary node (A in
connected DiffServ-compliant network devices. The boundary node (A in
) in a DiffServ network classifies (marks with a DSCP value) the incoming
packets into different traffic flows (Platinum, Gold, Silver, Bronze) based on the
configured marking rules. A network administrator can then apply various traffic
policies to the traffic flows. An example traffic policy, is to give higher drop
precedence to one traffic flow over others. In our example, packets in the Bronze
traffic flow are more likely to be dropped when congestion occurs than the packets
in the Platinum traffic flow as they move across the DiffServ network.
configured marking rules. A network administrator can then apply various traffic
policies to the traffic flows. An example traffic policy, is to give higher drop
precedence to one traffic flow over others. In our example, packets in the Bronze
traffic flow are more likely to be dropped when congestion occurs than the packets
in the Platinum traffic flow as they move across the DiffServ network.
Figure 171 DiffServ Network
36.2 Two Rate Three Color Marker Traffic
Policing
Policing
Traffic policing is the limiting of the input or output transmission rate of a class of
traffic on the basis of user-defined criteria. Traffic policing methods measure traffic
flows against user-defined criteria and identify it as either conforming, exceeding
or violating the criteria.
traffic on the basis of user-defined criteria. Traffic policing methods measure traffic
flows against user-defined criteria and identify it as either conforming, exceeding
or violating the criteria.
G S B
P
S
B
B
G P P
S
P - Platinum
G - Gold
S - Silver
B - Bronze
G - Gold
S - Silver
B - Bronze
G P P
S
A