When a Zoom call drops, a file download stalls, or an international client struggles to connect to your website, the blame often goes straight to “international internet problems.” The usual suspects? Submarine cable faults, congested international peering, or distant cloud provider hiccups.

But here's the truth: the number one cause of international connectivity complaints is not international at all—it’s last mile packet loss. And unless your business has visibility and mitigation in place, you’ll keep diagnosing the wrong problem and applying the wrong fix.

📦 What Is Last Mile Packet Loss—& Why Does It Happen?

The “last mile” refers to the final stretch of a network path—from your business premises to the nearest internet exchange or telco aggregation point. It’s the link between your router and your service provider’s core infrastructure. While submarine cables are built for speed and redundancy, the last mile is often the weakest, most error-prone segment of any network path.

Common Causes of Last Mile Packet Loss:

Electrical noise or signal degradation on copper (Ethernet) lines
LTE tower overload or unstable mobile signal strength
Fibre optical maintenance such as splicing or provisioning
Faulty CPE (Customer Premises Equipment). faulty optical termination devices or poorly configured routers
Congested or oversubscribed local fibre access
Power issues during loadshedding, affecting line equipment
Environmental factors such as weather, moisture, or rodents chewing cables 🐭

These issues result in dropped packets, jitter, and fluctuating latency—particularly under load or during peak hours. And because the path to international services relies on that same last mile, it presents itself as an international problem, even when global infrastructure is perfectly healthy.

🌐 Why International Traffic Suffers More from Last Mile Packet Loss

Not all packet loss is created equal—and not all traffic is equally affected. You may notice that local websites still load relatively fine, but international services crawl or time out completely when your connection is acting up. This is due to how modern communication protocols operate over distance and how they respond to packet loss.

🏘️ Local Traffic: Short Trips, Less Impact

When you're connecting to a local website hosted within your city or country, the number of network “hops” between you and the server is minimal. Round-trip times (RTT) are low—typically under 30ms—which means:

Lost packets are detected and retransmitted quickly
TCP congestion control algorithms recover faster
Protocol handshakes (like SSL/TLS) complete with less delay

Even if a few packets go missing due to a glitch in the last mile, your browser or application can recover quickly, often without a noticeable impact to the user.

🌍 International Traffic | The Long Haul Punished by Loss

Now contrast that with international cloud platforms hosted across continents. Every lost packet has to traverse thousands of kilometres, through multiple providers and internet exchange points. Round-trip latency is much higher—150ms to Europe, 200ms+ to the US.

When packet loss occurs over these longer paths:

Retransmissions take much longer, delaying the flow of data
TCP throughput drops dramatically, sometimes halving or more
Real-time services (Zoom, Teams, etc.) struggle to maintain quality
Secure connections take longer to establish or may fail outright

TCP (Transmission Control Protocol) was designed to treat packet loss as a sign of congestion. When it detects loss, it automatically reduces the sending rate—this reaction is proportional to the round-trip time, making international sessions far more sensitive to local packet problems.

In essence, a glitch in the last mile causes ripples that echo much louder across longer distances.

❌ Why Traditional Troubleshooting Misses It

Most ISPs perform only basic diagnostics. If there's link light and the bandwidth speed test checks out (momentarily), they declare the line healthy. But packet loss isn't always persistent—it can be intermittent, bursty, and invisible to standard tests.

Without deep telemetry or an intelligent overlay, businesses are often blind to the root cause, and spend time escalating tickets, rerouting traffic, or even migrating services—when the issue is metres away from their front door.

✅ How Fusion SD-WAN Fixes the Real Problem

Fusion’s SD-WAN solution doesn’t just provide another path—it understands and actively manages the last mile using advanced techniques designed to make unreliable links perform like premium circuits.

Key Technologies That Tackle Last Mile Packet Loss:

🔁 Overlay Transport with High-Speed Packet Reordering
Fusion runs a UDP-based overlay that tolerates packet loss and reorders out-of-sequence packets at line speed. This is crucial because traditional TCP connections slow down or collapse when packets are dropped or delivered out of order.

📉 Bandwidth Adaptation & Congestion Avoidance
Fusion SD-WAN detects when a link is becoming congested or dropping packets and proactively reduces throughput on that path—before degradation hits real traffic. By dynamically adjusting to real-world conditions, the overlay stays performant even under pressure.

🔀 Dynamic Path Steering and Load Sharing
When multiple links are present (e.g., fibre, LTE, satellite), Fusion steers high-priority traffic over the cleanest path and shifts away from degraded paths without human intervention.

🧠 Forward Error Correction (FEC) or packet duplication isn’t the solution

https://hubandspoke.amastelek.com/the-fallacy-of-packet-duplication-being-a-relevant-solution-for-sdwan

🌍 Why This Matters for Cloud-Dependent & Global-Facing Businesses

If your business relies on international cloud applications like Microsoft 365, AWS-hosted systems, or CRM platforms based in Europe or the US, your customers and employees will feel every packet lost in that last mile. Even a 1–2% packet loss can tank user experience—especially on VoIP, video, or real-time services.

Businesses in tourism, conferencing, or global collaboration also suffer when international visitors or partners can’t reliably connect to local services due to poor inbound performance.

With Fusion SD-WAN, you gain:

Resilient access to global services, even over problematic circuits
Predictable application performance for international traffic
Failover that’s fast enough to maintain active VPN sessions and calls
Visibility into link health, with a clear view of what’s really causing problems
Improved SLAs, by holding providers accountable to real metrics, not line sync

🔚 Wrapping Up | International Isn’t Always Global

Many South African businesses have spent fortunes chasing "international latency problems" that were actually last mile reliability issues. A satellite link might be blamed, when it's a burst of interference on a nearby LTE base station. A cloud app might be faulted, when the real issue is a noisy last mile line.

Fusion’s SD-WAN brings the intelligence, adaptability, and resilience businesses need to separate signal from noise—literally. By wrapping the last mile in a smart overlay that actively heals and adapts, businesses can finally stop guessing and start delivering consistent international performance.

So next time a call drops or a cloud app stalls, don't look to the ocean. Start by looking at the last mile—and make sure SD-WAN is looking with you. 🌐🚀

🧜🏻‍♀️ It’s Not the Submarine Cable | Why Most ‘International’ Connectivity Issues Are Local (& How SD-WAN Solves Them) 🔊