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

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QoS Shaping Mode for Ethernet Interfaces Overview
The SAR scheduler is not available for Ethernet interfaces. However, you can still
configure the operational shaping mode to shape ATM traffic based on either frames
or cells by issuing the
qos-shaping-mode command.
Frame shaping mode is the default for Ethernet interfaces on all E Series Broadband
Services Routers. You can configure cell shaping mode for the following interfaces:
■
Gigabit Ethernet interfaces on the GE-2 line module and the GE-HDE line module
on ERX routers
■
Gigabit Ethernet and 10-Gigabit Ethernet interfaces on the ES2 4G LM on E120
and E320 Broadband Services routers
■
10-Gigabit Ethernet interfaces on the ES2 10G LM on E120 and E320 routers
When you use cell shaping mode to configure the shaping or policing rate, the
resulting traffic stream conforms exactly to the policing rates configured in
downstream ATM switches. Using cell shaping also reduces the number of packet
drops in the Ethernet network.
The setting for port 0 provides the default shaping mode for all ports on the same
I/O module or IOA. Individual ports can have a specific shaping mode setting that
overrides the setting for port 0.
If you do not configure the QoS shaping mode for a port, the shaping mode is
calculated using the value for port 0 on the same I/O module or IOA. If the port's
shaping mode is configured, the system uses the port's shaping mode.
Table 19 on page 178 lists the possible combinations of the qos-shaping-mode
command and the resultant operational shaping mode.
Table 19: Operational Shaping Modes
Operational Shaping
Mode qos-shaping-mode
for Other Ports qos-shaping-mode
for Port 0
Cell Cell Cell
Frame Frame Frame
Frame Frame Cell
Cell Cell Frame
Frame No shaping mode Frame
Cell No shaping mode Cell
Frame No shaping mode No shaping mode
178 ■
QoS Shaping Mode for Ethernet Interfaces Overview
JUNOSe 11.1.x Quality of Service Configuration Guide