Not all internet connections are created equal for VoIP. I set up identical VoIP endpoints on 5 different connection types and measured call quality over 30 days. The results might change how you think about your office internet.
The Test Setup
- Same VoIP provider, same codec (Opus), same endpoint hardware
- 100 test calls per connection type (50 internal, 50 to PSTN)
- Measured: latency, jitter, packet loss, MOS score
- All tests during business hours (9 AM - 5 PM)
- 30-day test period to capture variability
The Results
Connection Type Comparison
| Connection | Speed | Avg Latency | Avg Jitter | Packet Loss | Avg MOS | Cost/Month |
|---|---|---|---|---|---|---|
| Dedicated Fiber | 100/100 Mbps | 6ms | 1.2ms | 0.00% | 4.5 | $400 |
| Business Cable | 200/20 Mbps | 18ms | 8.5ms | 0.12% | 4.2 | $120 |
| Residential Fiber | 500/500 Mbps | 9ms | 3.4ms | 0.02% | 4.4 | $70 |
| Residential Cable | 300/15 Mbps | 24ms | 15.2ms | 0.35% | 3.9 | $60 |
| 5G Fixed Wireless | 200/50 Mbps | 32ms | 22.8ms | 0.85% | 3.6 | $50 |
Key Findings
1. Dedicated fiber is the gold standard — but residential fiber is 98% as good at 1/5 the price. The difference between 6ms and 9ms latency is imperceptible to humans.
2. Upload speed matters more than download. VoIP is symmetrical — you send and receive equal amounts of data. Cable connections with 15-20 Mbps upload work fine for 5-10 simultaneous calls. But if you have 25 concurrent calls needing 2.5 Mbps, that 15 Mbps upload is maxed at 60%.
3. Jitter is the real killer, not speed. The 5G connection had plenty of bandwidth but wild jitter spikes (22.8ms average, with peaks over 80ms). High jitter causes choppy audio even when bandwidth is sufficient.
4. Time-of-day variation:
| Connection | Off-Peak MOS | Peak MOS | Degradation |
|---|---|---|---|
| Dedicated Fiber | 4.5 | 4.5 | 0% |
| Business Cable | 4.3 | 4.1 | 5% |
| Residential Fiber | 4.4 | 4.3 | 2% |
| Residential Cable | 4.2 | 3.5 | 17% |
| 5G Fixed Wireless | 3.8 | 3.2 | 16% |
Residential cable degrades significantly during peak hours (4-8 PM) when neighbors stream video. Dedicated and residential fiber are stable.
Recommendations by Business Size
| Business Size | Recommended Connection | Why |
|---|---|---|
| 1-5 users (home/small) | Residential fiber | Best value, nearly perfect quality |
| 5-15 users (small office) | Business cable or residential fiber | Sufficient upload, good quality |
| 15-50 users (medium office) | Business fiber | Need guaranteed bandwidth + SLA |
| 50+ users (large office) | Dedicated fiber | Zero compromise, SLA-backed |
| Remote workers | Any fiber > any cable > any wireless | Home fiber is fine |
The Budget Play
If you are a small business trying to save money: residential fiber + QoS configuration gives you 95% of the quality of dedicated fiber at 17% of the cost. The key is QoS — prioritize voice traffic and the connection handles it beautifully.
providers such as VestaCall (https://vestacall.com) with month-to-month contracts provides a free network readiness assessment that tests your specific connection for VoIP suitability before you commit.
