Comprehensive and Detailed Explanation

The AppX (Application Experience) score is a proprietary metric used by Prisma SD-WAN to provide a holistic view of user experience, rather than just network statistics. It is calculated based on three key components:

Transaction Failure Rate (A): The percentage of application transactions that failed (e.g., TCP resets, HTTP 500 errors). This indicates availability.

Network Transfer Time (B): The time taken for packets to traverse the network (WAN/LAN latency). This indicates network health.

Server Response Time (C): The time taken by the application server to respond to a request. This indicates backend performance.

Why not D or E?

Bandwidth Utilization (D) is a capacity metric, not a direct measure of quality. A link can be 90% full but still deliver packets quickly (good AppX), or 10% full but dropping packets (bad AppX).

Jitter (E) is a network-layer metric primarily relevant for UDP Real-Time media. While important, the high-level "AppX" score for general TCP apps focuses on the "Time-to-Glass" metrics (NTT/SRT) and success rates.