QoE Explained for the VMware Velocloud SD-WAN
Article ID: 312376
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Products
Issue/Introduction
QoE stands for Quality of Experience. This tab in the SD-WAN Orchestrator will help you gain an understanding of how each WAN transport link is performing and how VeloCloud DMPO (Dynamic Multi-Path Optimizations) are improving application performance. SD-WAN provides these scores through something called VQS (VeloCloud Quality Score). VQS helps an operator determine the quality of the underlying WAN transport connected to the VMware SD-WAN Edge.
Before
The 'Before' section of VQS indicates connection performance before DMPO. At a specified interval, the SD-WAN Orchestrator looks at latency, jitter, and loss across all paths and displays the path with the best metrics. A path, in a public overlay, is defined as Edge-to-Gateway. Paths in a private overlay are Edge-to-Edge. The measurements are unidirectional, upstream and downstream are separately measured.
Over time, the VQS score can be derived from multiple different paths depending on what was best at the interval. The intention is to abstract away path or peering issues of a specific path and provide an overall quality measurement of the underlying transport.
SD-WAN defines SLA Thresholds for latency, loss, and jitter in VQS that place measurements as: Good (10), Fair (5), or Critical (0). These thresholds change depending application. VQS allows you to select three different traffic types: Voice, Video, and Transactional. The thresholds for these traffic types are defined below:
Voice
| Latency | Loss | Jitter | |
| Good | =<25ms | =<0.30% | =<7ms |
| Fair | >25ms | >0.30% | >7ms |
| Critical | >65ms | >1.00% | >30ms |
Video
| Latency | Loss | Jitter | |
| Good | =<25ms | =<0.05% | =<5ms |
| Fair | >25ms | >0.05% | >5ms |
| Critical | >65ms | >0.10% | >10ms |
Transactional
| Latency | Loss | Jitter | |
| Good | =<50ms | =<1.00% | =<200ms |
| Fair | >50ms | >1.00% | >200ms |
| Critical | >80ms | >3.00% | >200ms |
After
The SD-WAN Enhancements VQS score indicates connection quality after Dynamic Multi-Path Optimizations are applied. Depending on the type of traffic and links available: packet steering, jitter buffering, forward error correction, and NACK optimizations are applied to mitigate application impact from degraded WAN link. Please check below chart for summary:
Environment
All VMware Velocloud SD-WAN supported versions
Resolution
The QoE is calculated based on best score comparing all the Static tunnels (Edge<->Gateways and Edge<->Hubs). Dynamic tunnels are not included into QoE score calculation.
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