Configuring CoS on ATM Interfaces

[Contents] [Prev] [Next] [Index] [Report an Error]

The ATM2 intelligent queuing (IQ) interface allows multiple IP queues into each virtual circuit (VC). On M-series platforms (except the M320 router), a VC tunnel can support four class-of-service (CoS) queues. On the M320 and T-series platforms for all ATM2 IQ PICs except the OC48 PIC, a VC tunnel can support eight CoS queues. Within a VC tunnel, the weighted round-robin (WRR) algorithm schedules the cell transmission of each queue. You can configure the queue admission policies, such as early packet discard (EPD) or weighted random early detection (WRED), to control the queue size during congestion.

For information about CoS components that apply generally to all interfaces, see CoS Overview and CoS Configuration. For general information about configuring ATM interfaces, see the JUNOS Network Interfaces Configuration Guide.

To configure ATM2 IQ VC tunnel CoS components, include the following statements at the [edit interfaces at-fpc/pic/port] hierarchy level:



[edit chassis fpc slot-number pic pic-number]

max-queues-per-interface number;
 
[edit interfaces at-fpc/pic/port]
atm-options {



linear-red-profiles profile-name {

high-plp-max-threshold percent;

low-plp-max-threshold percent;

queue-depth cells high-plp-threshold percent low-plp-threshold percent;
}



plp-to-clp;



scheduler-maps map-name {



forwarding-class class-name {

epd-threshold cells plp1 cells;

linear-red-profile profile-name;

priority (high | low);

transmit-weight (cells number | percent number);
}



vc-cos-mode (alternate | strict);
}


}
unit logical-unit-number {

atm-scheduler-map (map-name | default);



family family {



address address {

destination address;
}


}



plp-to-clp;



shaping {
(cbr rate | rtvbr peak rate sustained rate burst length  | vbr peak rate sustained rate burst length);
}



vci vpi-identifier.vci-identifier;
}

This section discusses the following topics:

[Contents] [Prev] [Next] [Index] [Report an Error]