Nortel BCM 3.7, Manual

Page: 795 / 1004

795
Programming Operations Guide
Chapter 40
Policy-enabled networking
This section discusses the Policy services you can configure to enhance your data network.
Included is the following information:
• “Policy configuration overview” on page 795
• “Implementing Quality of Service (QoS)” on page 801
• “Implementing Common Open Policy Services (COPS)” on page 811
• “Configuring the Policy Agent characteristics” on page 816
Policy configuration overview
Business Communications Manager enables system administrators to implement classes of service
and assign priority levels to different types of traffic. Using Unified Manager, you can configure
policies that monitor the characteristics of traffic (for example, its source, destination, and
protocol) and perform a controlling action on the traffic when certain user-defined characteristics
are matched.
This section includes information about:
• “Differentiated Services (DiffServ) overview” on page 795
• “COPS” on page 800
• “Policy overview” on page 800
Differentiated Services (DiffServ) overview
This section provides information about working with DiffServe, including:
• “DiffServ IP Quality of Service (QoS) architecture” on page 796
• “DiffServ components” on page 797
• “IP service classes” on page 798
• “Packet classifiers” on page 799
Differentiated services (DiffServ) is a Quality of Service (QoS) network architecture that offers
varied levels of service for different types of data traffic. DiffServ allows you to designate a
specific level of performance on a packet-by-packet basis instead of using the “best-effort” model
for your data delivery. You can give preferential treatment (prioritization) to applications that
require high performance and reliable service, such as voice and video over IP.
Business Communications Manager includes the capability to enhance your network traffic
management. For each packet, there is an octet in the packet header, the DiffServ (DS) field, that
you can designate for specific service. For IP packets, six bits of the DiffServ field is the
DiffServ
Code Point ( DSCP) . The DSCP value defines how the packet is to be treated as it travels through
the network. You can set traffic criteria to match the DS field, and policy actions to change the
DiffServ field to conform to various other mappings.