Service flows – ADC CUDA 3 User Manual

Page 473

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Cuda 12000 IP Access Switch CLI-based Administration Guide

Managing Quality of Service

471

Service Flows

A Service Flow is a QoS protocol mechanism that serves as a MAC-layer
transport service and provides a unidirectional flow of packets transmitted
either upstream by the cable modem or downstream by the CMTS. A Service
Flow is characterized by a Service Flow ID (SFID), the service ID (SID) and a set
of QoS parameters. A SID refers only to packets transmitted upstream.

There are three types of QoS parameter sets, as follows:

Table 19-10 QoS Parameter Set Types

At registration, at least two Service Flows are defined per cable modem
configuration file, one for the upstream and one for the downstream. The
first upstream Service Flow describes the primary upstream Service Flow and
is the default Service Flow used for upstream unclassified traffic. The first
downstream Service Flow describes service to the primary downstream
Service Flow and is the default Service Flow used for downstream
unclassified traffic.

Parameter Set

Description

ProvisionedQosParamSet

Service Flow Provisioned QoS Parameters
are in the configuration file and are
introduced during registration.

AdmittedQoSParamSet

Service Flow Admitted QoS Parameters
define how the CMTS is reserving
resources. (The CM may also reserve
resources.) Examples of resources that are
reserved are bandwidth and other
memory or time-based resources that are
required to activate the flow.

ActiveQosParamSet

Service Flow Active QoS Parameters define
what is actually being provided to the
Service Flow.

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