Juniper JUNOSE 11.1.X - QUALITY OF SERVICE CONFIGURATION GUIDE 3-21-2010, Configuration Manual

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associated with the qos-cell-mode application to determine whether the cell
adjustment is required.
NOTE: Do not use the parameter expression on Ethernet interfaces configured on
the ES2 4G LM, GE-2 line module, or the GE-HDE line module.
For example, the subscriber-rate parameter represents the bandwidth of a subscriber.
The shaping rate for the parameter is calculated by referencing an expression that
represents the cell mode adjustment in a scheduler profile:
(config-scheduler-profile)# shaping-rate subscriber-rate - subscriber-rate * cell-mode
% 25
The subscriber-rate - subscriber-rate * cell-mode % 25 expression provides for an
explicit cell-tax factor of 25 percent when the subscriber local loop is transmitting
cells. In cases where the local loop is very-high-bit-rate digital subscriber line (VDSL),
the second term in the expression drops to 0.
Relationship with QoS Downstream Rate Application
ANCP dynamically controls the QoS cell mode application when you create parameter
instances for VLANs using both the QoS downstream rate application and the QoS
cell mode application.
ANCP controls QoS cell mode parameter instances at the VLAN subinterface only;
the protocol does not control parameter instances at the major Ethernet interface or
S-VLAN subinterface.
Related Topics
■
Configuring a Parameter Definition to Shape Ethernet Traffic Using Cell Mode
on page 284
■
Example: QoS Parameter Configuration for QoS Cell Mode and Byte Adjustment
for Cell Shaping on page 286
■
For more information about configuring the QoS shaping mode, see QoS Shaping
Mode for Ethernet Interfaces Overview on page 178
■
For more information about configuring scheduler rates for QoS parameters, see
Scheduler Profiles and Parameter Expressions for QoS Administrators on page 235
■
For more information about shaping the downstream rate using QoS parameter
instances that were created dynamically by ANCP, see QoS Downstream Rate
Application Overview on page 301
Guidelines for Configuring the Cell Shaping Mode with QoS Parameters
When you specify the QoS cell mode application, the following considerations apply:
Guidelines for Configuring the Cell Shaping Mode with QoS Parameters
■ 283
Chapter 28: Configuring the Shaping Mode for Ethernet with QoS Parameters