Configuration Guide User guide

1972 FastIron Configuration Guide

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QoS queues

The queue names listed in Table 333 are the default names. If desired, you can rename the

queues as shown in “Renaming the queues” on page 1989.

Packets are classified and assigned to specific queues based on the criteria shown in Figure 220,

Figure 221, and Figure 222.

For FCX and ICX devices, ingress packets are classified into the eight priorities, which map to eight

hardware queues or traffic classes (TCs) based on the priority. Exceptions to this model are the

SX-FI48GPP and SX-FI-8XG interface modules and the ICX 6430 switch as explained in the

following sections.

Queues for the SX-FI48GPP interface module

The SX-FI48GPP interface module consists of two separate hardware Network Processors (NPs).

The front-end NP supports four hardware queues, and the back-end NP supports eight hardware

queues. Ingress packets are classified into eight priorities mapped into four hardware queues. In

the egress, traffic is destined to two adjacent network ports (for example, ports 1/1 and 1/2), and

aggregated into one 1-GbE port in the back-end NP. The two network ports share the same

hardware queues, and therefore they have the same buffer and descriptor limits and scheduling

algorithm for transmission.

Ingress packets are classified into eight QoS priority levels at the front-end NP of the SX-FI48GPP

module. The eight priorities are mapped into four hardware queues based on the priority queue

configuration in Table 334. QoS priority 7 is the highest priority, and QoS 0 is the lowest priority.

TABLE 334 Priority queues for the SX-F148GPP

QoS classification occurs in two iterations; initially in the front-end NP, followed by the back-end NP.

The back-end NP has the same classification and marking capabilities of existing FastIron SX

interface modules, but the front-end NP does not support ACL and static MAC priority. The front-end

NP supports basic QoS features, such as port priority, QoS-ToS mapping, 802.1p to priority

mapping, 802.1p override, and trust DSCP mode.

The default scheduling configuration for Weighted Round Robin (WRR), Hybrid WRR and Strict

Priority (SP), and SP mode for the eight QoS priority queues mapped to the four hardware queues is

described under “Default scheduling configuration for the SX-FI48GPP module” on page 1985.

QoS priority level Hardware queues

(traffic classes)