Recently, I worked on optimizing a VDSL2 connection provided by Telecom (Argentina). By configuring the modem in bridge mode and managing the PPPoE authentication directly from a MikroTik router, the main objective was to reduce bufferbloat and improve the quality of experience for latency-sensitive applications such as video calls, online gaming, and streaming platforms. 🎯
📌 Actions Implemented
- ✅ TCP MSS Adjustment — Enabled MSS clamping to prevent fragmentation issues, especially critical on PPPoE connections. This improved page loading and overall stability.
- ✅ CAKE Queues with Per-Subnet Limits — Applied strict upload and download limits for two network segments (Apartment and Home), ensuring fair bandwidth distribution and minimizing latency.
- ✅ Mangle Rules for Traffic Classification and Marking — Prioritized streaming traffic (YouTube, Stremio, etc.) using DSCP streaming-video marks; identified and controlled mobile app traffic (Instagram, Facebook); applied specific classification for devices like Mi Box for granular management.
- ✅ DiffServ4 Mode in CAKE — Allowed DSCP priorities to be properly interpreted by the queueing algorithm, reinforcing quality-of-service control.
📊 Results Achieved
- Improved bufferbloat score from F → A+.
- Upload latency under load dropped from +600 ms → +2 ms.
- Stable performance in video calls (Google Meet, Zoom, WhatsApp), online gaming, and streaming services.
📷 Before/After and Config Highlights
Attached are comparative screenshots showing performance before and after, along with the marking rules and queue configurations applied. These adjustments transformed a standard home connection into one with professional-grade performance.
🧠 Key Insight
Often, the problem is not the contracted speed, but rather how the traffic is managed. With the right configuration, the difference in user experience can be dramatic.