Configuring Linear RED Profiles on ATM Interfaces

Linear random early detection (RED) profiles define CoS virtual circuit drop profiles. You can configure up to 32 linear RED profiles per port. When a packet arrives, RED checks the queue fill level. If the fill level corresponds to a nonzero drop probability, the RED algorithm determines whether to drop the arriving packet.

To configure linear RED profiles, include the linear-red-profiles statement at the [edit interfaces at-fpc/pic/port atm-options] hierarchy level:

[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;}

The queue-depth, high-plp-threshold, and low-plp-threshold statements are mandatory.

You can define the following options for each RED profile:

high-plp-max-threshold—Define the drop profile fill-level for the high packet loss priority (PLP) CoS VC. When the fill level exceeds the defined percentage, all packets with high PLP are dropped.
low-plp-max-threshold—Define the drop profile fill-level for the low PLP CoS VC. When the fill level exceeds the defined percentage, all packets with low PLP are dropped.
queue-depth—Define maximum queue depth in the CoS VC drop profile. Packets are always dropped beyond the defined maximum. The range you can configure is from 1 through 64,000 cells.
high-plp-threshold—Define CoS VC drop profile fill-level percentage when linear RED is applied to cells with high PLP. When the fill level exceeds the defined percentage, packets with high PLP are randomly dropped by RED.
low-plp-threshold—Define CoS VC drop profile fill-level percentage when linear RED is applied to cells with low PLP. When the fill level exceeds the defined percentage, packets with low PLP are randomly dropped by RED.