what causes packet loss

Packet loss happens when some of the data packets traveling across a network never reach their destination, usually because something along the path is overloaded, broken, or misconfigured.

Quick Scoop: Core Causes of Packet Loss

Think of the network like a busy highway: if there are too many cars, potholes, or bad signs, some cars never make it to the exit. Packet loss works the same way.

1. Network congestion (the “rush hour” problem)

When more traffic hits the network than it can handle, devices like routers and switches run out of buffer space and start dropping packets. This is common:

• During peak hours on home or office internet.

• On links with too little bandwidth for video calls, games, and large downloads at the same time.

Real-world example: Your 6 PM video call stutters, but works fine at 11 PM—classic congestion-driven packet loss.

2. Faulty or weak network hardware

Any weak link in the hardware chain can cause packets to disappear.

• Failing or overloaded routers, switches, or firewalls.

• Damaged or low-quality Ethernet cables and connectors.

• Overheated or old devices running at the edge of their capacity.

A half-broken switch port or kinked cable might only show issues when traffic spikes, making packet loss feel random.

3. Wireless issues and interference

Wi‑Fi is especially prone to packet loss because radio signals are fragile.

• Interference from microwaves, cordless phones, neighboring Wi‑Fi networks.

• Physical obstacles (walls, floors, metal, concrete) weakening signal strength.

• Clients far from the access point, with low signal and high noise.

On Wi‑Fi, this often shows up as “good speed test, but games and calls still lag” because real‑time traffic is hit hardest by retries and drops.

4. ISP and upstream network problems

Sometimes the problem isn’t in your local network at all, but out in your provider’s infrastructure or further along the route.

• Congested or saturated links inside the ISP’s backbone.

• Faulty long‑distance lines or bad routing paths.

• Maintenance, misconfiguration, or temporary failures at intermediary networks.

You’ll often see this as packet loss starting at a certain “hop” in traceroute or pathping, not at your router.

5. Software bugs and configuration errors

Even if cables and hardware are healthy, bad logic or settings can drop packets.

• Buggy firmware on routers, switches, or firewalls.

• Outdated or corrupted network drivers and OS networking stacks on PCs or servers.

• Misconfigured MTU (too large packets → fragmentation issues and drops).

• Incorrect routing, QoS, or firewall rules that discard valid traffic.

Example: An overly strict firewall rule meant to block attacks ends up dropping legitimate VoIP packets.

6. Security attacks and malicious traffic

Some packet loss is deliberate, caused by attackers or abuse of the network.

• DDoS attacks flooding a server or router so it cannot process all packets.

• Other security breaches or abuse that create huge traffic spikes and overload devices.

You might see sudden, heavy packet loss during such events, often targeted at public-facing services.

7. Signal quality, noise, and medium limitations

On wired or wireless links, the physical medium itself can be the culprit.

• Insufficient signal strength at the receiver.

• Natural or human-made interference adding noise to the channel.

• Long cable runs outside spec, or old copper lines with high error rates.

These issues increase bit errors on the line; when error correction fails, packets are dropped.

Mini FAQ: How this shows up in real life

• Online games: rubber-banding, teleporting, hit registration issues.

• Video calls: frozen video, choppy audio, “Reconnecting…” messages.

• Streaming: random buffering or sudden quality drops despite high bandwidth.

• File transfers: failed uploads/downloads or corrupted transfers.

In short, packet loss is caused by overloaded paths, broken or misconfigured equipment, noisy or weak links, and sometimes outright attacks—anything that keeps packets from cleanly crossing the network from source to destination.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.