Prisma SD-WAN implements a class-based Quality of Service (QoS) system on each WAN interface. This system is structured around four predefined traffic classes: Class 1 (Real-time), Class 2 (Interactive), Class 3 (Default), and Class 4 (Bulk). Within each of these four classes, traffic can be further categorized by four application criteria: High, Medium, Low, and Lowest. This hierarchical structure creates a 4x4 matrix, resulting in a total of 16 distinct queues that are used to prioritize and manage traffic, ensuring that critical applications receive the appropriate network resources.

A. This option is incorrect because Prisma SD-WAN uses four application criteria within each class, not three, which would only result in 12 queues.

C. This option incorrectly describes the queue structure; Prisma SD-WAN uses a 16-queue, class-based system, not a simple 1 priority plus 7 non-priority queue model.

D. This option is incorrect as it states there are only two classes. The Prisma SD-WAN QoS model is built upon four distinct traffic classes.

1. Palo Alto Networks. (2023). Prisma SD-WAN Administrator's Guide. Palo Alto Networks TechDocs. In the section "Policies > Quality of Service (QoS) > Traffic Classes," the guide states, "Prisma SD-WAN provides four predefined traffic classes... Within each of these four classes, you can define four application criteria: High, Medium, Low, and Lowest. This results in 16 queues for traffic prioritization."