Chapter 7 Traffic Accounting; Layer 2 Overhead Accounting - Cisco 10000 Series Configuration Manual

Traffic Accounting
This chapter describes traffic accounting features and includes the following topics:
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Layer 2 Overhead Accounting

Layer 2 overhead accounting enables the Cisco 10000 series router, acting as the broadband access
system (BRAS), to account for various encapsulation types when applying QoS to packets. This
accounting ensures that the actual bandwidth used by packets does not exceed the bandwidth of the
subscriber line.
In a typical DSL-based broadband access ANCP environment, when the DSL circuit adjusts the line
speed based on signal quality, the DSLAM uses ANCP to notify the BRAS of the change. The BRAS
responds to the notification by shaping subscriber traffic in the downstream direction. QoS policies
configured on the BRAS and applied to the entities on which subscriber sessions terminate enable the
BRAS to implement these traffic control features.
Figure 7-1
OL-14660-03
Layer 2 Overhead Accounting, page 7-1
Per-Service Accounting, page 7-12
QoS Service Accounting, page 7-14
ANCP Corrected Rate, page 7-15
Verifying Traffic Accounting, page 7-18
shows a broadband access ANCP network.
Cisco 10000 Series Router Access Network Control Protocol Configuration Guide
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