Zero-Cost Connectivity Repair: How a Simple DNS Routing Adjustment Saved a £375k Wi-Fi Replacement
Network Diagnostics • Infrastructure Audit • Enterprise Wi-Fi
Strategic Summary: Enduring persistent Microsoft Teams call drops, the CEO of a Cape Town asset management firm issued an ultimatum to scrap and replace their entire Fortinet Wi-Fi estate. A systematic network audit by Si Futures revealed the hardware was pristine—the true culprit was a misconfigured DNS resolver routing local traffic to European servers. Changing the resolver reduced latency by 87% and saved over £375,000 in unnecessary capital expenditure.
Challenge: Executive Ultimatums & TAC Configuration Chaos
The executive leadership of a prominent asset management firm faced months of exasperating Microsoft Teams disruptions during high-stakes client meetings at their Cape Town headquarters. Frustrated by recurring call drops, the CEO issued a blunt directive: replace the entire Fortinet wireless network immediately.
- Massive Capex Imminent: Facing a forced hardware overhaul projected to exceed £375,000.
- TAC Support Fatigue: Repeated tickets with Fortinet’s Technical Assistance Centre (TAC) yielded conflicting advice, leaving controller configurations fragmented.
- Unresolved Root Causes: Traditional wireless troubleshooting failed to isolate why call drops persisted despite strong RF signal coverage.
Ethical Consulting Over Hardware Sales
It would have been easy to agree with executive assumptions and sell a brand-new wireless estate. Instead, Si Futures initiated a methodical, two-phase diagnostic audit to verify whether physical hardware was truly at fault before committing capital.
Approach: Heat Mapping & In-Depth Telemetry
Partnering with Duxbury, Si Futures executed a two-phase remediation plan:
Phase 1: Wireless Controller Cleanup
Engineers purged conflicting TAC policies, restored stable baseline radio parameters, and optimized density by enabling additional 5GHz radios across existing access points. Site heat mapping confirmed the physical RF environment was fundamentally healthy.
Phase 2: Deep Endpoint Telemetry
Probes were deployed across the local network to monitor packet paths, jitter, and latency targeting specific Microsoft 365 real-time voice endpoints.
Figure 1: Telemetry telemetry dashboard revealing severe packet loss and 158ms latency due to European DNS resolution.
The diagnostic breakthrough revealed that local FortiGuard DNS resolvers were directing Microsoft Teams traffic to European data centres instead of local South African nodes, injecting 158ms of latency and dropping real-time UDP voice packets.
Measurable Outcomes & Zero-Cost Resolution
By updating upstream DNS resolvers to high-performance local providers (Cloudflare / Google), latency collapsed instantly:
- 87% Latency Reduction: Voice packet response dropped from 158ms to 21ms immediately.
- Zero Call Drops: Monitored over 30 days post-change with zero recorded drops on executive Teams sessions.
- £375,000 Capital Preservation: Existing Fortinet access points remained in place, fully validated and stable.
- Restored Executive Confidence: IT department credibility protected through rapid, cost-free problem resolution.
Figure 2: Telemetry telemetry following DNS re-routing showing 21ms local response times and zero packet loss.
Client Perspective & Lasting Value
“Si Futures saved us from making a costly mistake. They could have easily sold us new infrastructure, but instead they solved our real problem for the cost of a DNS configuration change. Our CEO’s Teams calls haven’t dropped once since then.”
Systematic network diagnostics ensure you solve the underlying operational root cause rather than replacing functional hardware.
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