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

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node
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qos-parameter
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qos-parameter-define
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qos-profile
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queue
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traffic-class
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vlan id
Configuring a Parameter Definition to Adjust Frame Shaping Rates for VDSL Traffic
Packet fragmentation can occur at a DSLAM because of the associated segment
header that is added for VDSL2 in frame shaping mode. Because the segment header
is not included in the ANCP rate report, the forwarding rate on an E Series router
can be higher than the DSLAM rate, which can result in packet loss.
You can use a QoS parameter expression with the frame byte-adjustment application
to reduce the forwarding rate so that it matches the VDSL downstream rate at the
DSLAM. You can also configure the cell mode application to account for ADSL
downstream traffic that is also being received.
To configure a QoS parameter definition to adjust frame shaping rates and manage
packet fragmentation:
1.
Configure the QoS parameter definition to accept downstream shaping rate
instantiation from ANCP.
host1(config)# qos-parameter-define ancp-downstream application
qos-downstream-rate
2.
Configure the QoS parameter definition for the frame byte-adjustment application
to adjust the packet header.
host1(config)# qos-parameter-define frame-byte application
qos-frame-byte-adjustment
You can also configure the qos-byte-adjustment application with a different value.
3.
Create the QoS parameter definition for the cell mode application to track the
subscriber DSL type.
host1(config)# qos-parameter-define sp-qos-cell-mode application qos-cell-mode
The ADSL type corresponds to cell mode and VDSL corresponds to frame mode.
4.
Configure the parameter expression to reduce the shaping rate to account for
packet fragmentation.
In the following expression, the adjustment is applied to traffic with frame shaping
mode only. The byte adjustment value is 8 and the shaping rate is reduced by
2 percent.
Configuring a Parameter Definition to Adjust Frame Shaping Rates for VDSL Traffic
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Chapter 29: Configuring Byte Adjustment for Shaping Rates with QoS Parameters