MX CoS Capabilities

This section provides an overview of Trio-based MX router CoS capabilities and operation, which includes a packet walkthrough that illustrates how CoS is provided to transit traffic in the Trio architecture.

The Trio chipset offers several CoS differentiators that should be kept in mind when designing your network’s CoS architecture.

Intelligent Class Aware Hierarchical Rate Limiters

This feature lets Trio PFEs honor user configured rate limit (shaping) policies for multiple classes of traffic, while at the same time protecting conforming high-priority traffic from low-priority traffic bursts. This is accomplished though support of up to four levels of scheduling and queuing (Ports/IFL sets/IFLs/Queues), with support for a shaping rate (PIR), a guaranteed rate (CIR), and excess rate control at all levels.

Additionally, you have great flexibility as to the attachment points for hierarchical scheduling and shaping, to include IFDs (ports), IFLs (logical interfaces), and interface sets (which are collections of IFLs or VLANs, and the key enabler of H-CoS).

Priority-Based Shaping

This feature allows you to shape traffic at an aggregate level based on its priority level, either at the port or IFL-set levels. Priority-based shaping is well suited to broadband aggregation where large numbers of individual flows are combined into larger class-based aggregates, which can now be shaped at a macro level.

Dynamic Priority Protection

Priority inheritance combined with the ability ...

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