If you’ve ever experienced your internet slowing down during peak hours, you’ve felt the impact of contention ratio, and if you rely on cloud apps, voip, and video conferencing, you’ll probably also know that inconsistent speeds can be costly.
That’s where leased lines come in, as leased lines don’t have a contention ratio, they provide dedicated bandwidth solely for your business.
So join us as in this guide, we’ll explain what contention ratio is, why it matters, and why leased lines are the gold standard for uncontended internet.
Contention Ratio Explained
Contention ratio refers to the number of users sharing the same data capacity on a broadband connection – so, in simple terms, it’s how many people you’re “competing” with for bandwidth.
For example:
- A 20:1 contention ratio means up to 20 users are sharing the same capacity.
- During busy periods, your speeds will drop as more people use the service simultaneously.
This is common in residential and business broadband, where providers oversubscribe capacity to keep prices lower.
Typical Contention Ratios in UK Broadband
Still today, most broadband services still operate with some level of contention:
|
Connection Type |
Typical Contention Ratio |
Impact on Business |
|
Residential Broadband |
20:1 to 50:1 |
Significant slowdowns at peak times |
|
Business Broadband (FTTC/FTTP) |
10:1 to 20:1 |
Better than residential, but speeds still fluctuate |
|
Leased Line |
1:1 (Uncontended) |
No slowdowns, dedicated performance |
This highlights to us why many UK businesses move away from standard broadband to leased lines when reliability becomes mission-critical.
Why Contention Ratio Matters for Businesses
For smes and enterprises, downtime or slow speeds aren’t just inconvenient, they directly impact productivity and revenue. Here’s how contention ratio affects operations:
- Video calls can lag and buffering on Teams, Zoom, or Google Meet.
- Cloud applications means sluggish performance with Microsoft 365, Google Workspace, or crms.
- Voip calls – dropouts and poor call quality caused by bandwidth fluctuations.
- Data transfers where large file uploads/downloads taking much longer during peak times.
- Customer experience / online services slowing down, leading to frustration and lost business.
A high contention ratio might be fine for home users, but for businesses, it creates unpredictable performance that can undermine growth.
Why Leased Lines Don’t Have a Contention Ratio
The biggest advantage (in our opinion) of a leased line is its uncontended connection, and with a leased line:
- Your business has a dedicated 1:1 connection.
- Bandwidth is reserved exclusively for your use.
- Performance is consistent 24/7, regardless of network congestion.
- Upload and download speeds are symmetrical, making it ideal for hybrid teams and cloud workloads.
In other words, leased lines completely remove the unpredictability of shared broadband.
Leased Line vs Broadband: Contention in Action
|
Feature |
Leased Line |
Business Fibre Broadband |
|
Contention Ratio |
1:1 (Uncontended) |
10:1 to 20:1 (Shared) |
|
Speed Consistency |
Always the same |
Slows during peak hours |
|
Uploads |
Symmetrical |
Slower than downloads |
|
Uptime Guarantees |
99.9%+ with SLA |
Best-effort only |
|
Best For |
Mission-critical, cloud-heavy businesses |
Smes with light to moderate needs |
UK Providers Offering Uncontended Leased Lines
Here are some of the top providers delivering leased line uncontended internet for UK businesses:
| Provider | Redundancy options | Dual carrier Support? | From |
|
|
Diverse routing, dual links | Yes | £399 + redundancy |
|
|
Dual-site connectivity | Yes | £400 + |
|
|
Separate routes, SD-WAN | Yes | £450 + |
|
|
Active-passive options | Limited | £300 + |
|
|
Multi-site and resilient WAN | Yes | £375 + |
When Should a Business Switch to a Leased Line?
While standard fibre broadband may work for small offices with light internet usage, we think that you should consider upgrading to a leased line if:
- Your team regularly uses cloud-based apps (Microsoft Azure, AWS, Salesforce).
- You rely on VoIP or video conferencing for daily operations.
- Your company manages sensitive data requiring stable and secure connectivity.
- You have multiple remote workers connecting via VPN.
- Internet downtime would cause financial or reputational damage.
Our Final Thoughts
we think that contention ratio is one of the least understood aspects of broadband, yet one of the most important for UK businesses, and while traditional broadband shares capacity between multiple users, leased lines eliminate the problem entirely with uncontended, symmetrical, and guaranteed connectivity.
We see that the demand for uncontended leased lines is stronger than ever. If reliable internet is critical to your operations, a leased line is a great investment in stability and growth.