CANOGA PERKINS CanogaOS Configuration Guide - Manual (Page 267)

CanogaOS Configuration Guide
Proprietary & Confidential Canoga Perkins Metro Ethernet Switches Page 267 of 350
Classification occurs on an ingress physical port, but not at the switch virtual interface level.
Classification can be based on CoS/DSCP/IP-Precedence, default port cos, or class maps and
policy maps.
Shaping
Shaping is to limit the rate at which packets pass through the shaper by buffering packets that
exceed a defined rate and sending those packets later. The goal is that, over time, the rate of
transmission will be smoothed out to the defined rate.
Shaping has the following attributes:
• Shaping can occur only on a physical port basis
• Shaping can occur on egress interface.
Policing
Policing determines whether a packet is in or out of profile by comparing the internal priority to
the configured policer.
The policer limits the bandwidth consumed by a traffic flow. The result is given to the marker.
There are two types of policers:
• Individual: QoS applies the bandwidth limits specified in the policer, separately, to each
matched traffic class. An individual policer is configured within a policy map.
• Aggregate: QoS applies the bandwidth limits specified in an aggregate policer, cumulatively, to
all matched traffic flows. An aggregate policer is configured by specifying the policer name
within a policy map. The bandwidth limits of the policer are specified. In this way, the aggregate
policer is shared by multiple classes of traffic within one or multiple policy map.
Policing and policers have the following attributes:
• Policers can occur only on a physical port basis.
• Policing can occur on ingress or egress of interfaces.
Marking
Marking determines how to handle a packet when it is out of profile. It assesses the policer and
the configuration information to determine the action required for the packet, then handles the
packet using one of the following methods:
• Let the packet through and mark color down
• Drop the packet
Marking can occur on ingress and egress interfaces.
Queueing