Airtel Dark Tunnel Config File Download Extra Quality Apr 2026

Values are averaged across 10 DWDM spans (200 km–800 km). The modest capacity reservation (≈ 4 %) is justified for premium‑SLA services. | Threat | Mitigation | |--------|------------| | Man‑in‑the‑Middle (MITM) on CFD | Mutual TLS, certificate pinning, and short‑lived signatures (TTL ≤ 24 h). | | Configuration replay | Version numbers and valid_until timestamps; agents reject older versions. | | Key compromise | Automated key‑rotation (90‑day cycle) via HashiCorp Vault; immediate revocation list broadcast. | | Denial‑of‑Service on CFD server | Rate‑limit per‑agent, CDN front‑end, and HA load‑balancer. | | EQ‑policy abuse | Policy‑engine validation – only pre‑approved traffic classes can request EQ (via service‑catalog). |

Prepared for: Internal Technical Review – Airtel Network Operations Date: 15 April 2026 1. Executive Summary Airtel Dark Tunnel is the carrier‑grade, encrypted overlay that connects Airtel’s core data‑center sites, edge‑computing nodes, and partner‑cloud PoPs over a “dark‑fiber” or leased‑line infrastructure. The recent focus on Config‑File Download (CFD) and Extra‑Quality (EQ) features aims to: Airtel Dark Tunnel Config File Download Extra Quality

All steps are logged in the for audit. 5. Performance & Quality Impact | Metric | Baseline (no EQ) | With EQ (lab) | Observed in field (Jan‑2026) | |--------|------------------|---------------|-------------------------------| | Latency (p99) | 3.4 ms (DWDM 600 km) | 2.8 ms | 2.9 ms | | Jitter (p99) | 0.45 ms | 0.12 ms | 0.14 ms | | Packet loss | 0.08 % | < 0.01 % (FEC) | 0.015 % | | Throughput impact | — | ~‑4 % of link capacity (reserved for EQ) | −3.5 % | | Config‑apply time | 12 s (manual) | 5 s (CFD) | 4.8 s | Values are averaged across 10 DWDM spans (200 km–800 km)

The report outlines the architectural context, the CFD workflow, the EQ mechanisms, security considerations, performance impact, and recommended next steps for production deployment. | Term | Definition | |------|------------| | Dark Tunnel | An IP‑over‑DWDM or MPLS‑based tunnel that runs over unused (dark) fiber or leased lines, offering a private, low‑latency backbone isolated from public Internet traffic. | | Config‑File Download (CFD) | A controlled process whereby tunnel‑endpoint devices (e.g., routers, optical line terminals) pull a signed configuration file from a centralized repository (GitOps/CMDB). | | Extra‑Quality (EQ) | A set of QoS augmentations (traffic‑class mapping, shaping, policing, and latency‑aware routing) applied to selected traffic classes to meet SLA‑grade performance. | | | Configuration replay | Version numbers and