Cisco uBR10012 Software Configuration Manual page 57

Chapter 1 Overview of Cisco uBR10012 Universal Broadband Router Software
Each service flow has a set of QoS attributes associated with it. These QoS attributes define a particular
class of service and determine characteristics such as the maximum bandwidth for the service flow and
the priority of its traffic. The class of service attributes can be inherited from a preconfigured CMTS
local service class (class-based flows), or they can be individually specified at the time of the creation
of the service flow.
Each service flow has multiple packet classifiers associated with it, which determine the type of
application traffic allowed to be sent on that service flow. Each service flow can also have a Payload
Header Suppression (PHS) rule associated with it to determine which portion of the packet header will
be suppressed when packets are transmitted on the flow.
Figure 1-3
Note By default, the system does not enforce any specific QoS profile on the CM. The QoS profile
assigned to the CM depends on the class of service parameters provisioned in the CM's DOCSIS
configuration file.
Figure 1-3
DOCSIS 1.1 Type of Service Overwrite
This feature allows you to overwrite the ToS byte in the IP datagrams received on the upstream before
forwarding them downstream.
OL-1520-05
illustrates the mapping of packet classifiers.
Classification Within the MAC Layer
Upper layer entity
(bridge, router)
mgmt
msgs
Primary DSFID
DSFID 2
Downstream
classifier
DSFID n
Downstream
service flows
Upstream
classifier
Cisco uBR10012 Universal Broadband Router Software Configuration Guide
Supported Software Features for the Cisco uBR10012 Router
MAC
Downstream
RF
CMTS
Upper layer entity
(bridge, router, client)
(Optional)
Ingress classifier
MAC
Mgmt
Msgs
Primary SID
SID 2
Upstream
classifier
SID n
Upstream service
flows
CM
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