What Is a Contention Ratio and Why Does It Matter for Business Broadband?
A clear, direct answer to this question — written for UK business owners and IT decision-makers.
Direct Answer
A contention ratio is the number of users sharing the same bandwidth capacity. Business broadband typically has contention ratios of 20:1 to 50:1 — meaning up to 50 businesses share the same connection. A leased line has a contention ratio of 1:1: the bandwidth is dedicated exclusively to your business. For VoIP, cloud applications, or any service where consistent performance matters, 1:1 contention is the only acceptable standard.
Key Points
What you need to know.
The Short Answer
A concise overview of what you need to know.
For UK Businesses
How this applies specifically in the UK context.
Cost Considerations
What to expect in terms of investment and ongoing costs.
Next Steps
What you should do with this information.
Quick Comparison
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Frequently Asked Questions
SD-WAN can reduce WAN costs by approximately 50% compared to traditional MPLS. The UK SD-WAN market is projected to grow from $4.8 billion in 2025 to $14.6 billion by 2031. SD-WAN is complementary to — not a replacement for — dedicated leased lines for primary connectivity.
This depends on your number of users and applications. VoIP requires approximately 100 Kbps per call. Cloud applications and video conferencing need more. The UK average business broadband speed is 131 Mbps, but 20% of UK businesses report insufficient internet speeds for their needs.
UK businesses lost £3.7 billion to internet outages in 2023. Small businesses lose £350-£450 per minute of downtime. 92% of UK businesses take 24 hours or longer to recover from a significant outage. Backup connectivity and failover solutions are essential for business continuity.
A leased line provides dedicated, uncontended bandwidth exclusively for your business. Unlike broadband, leased lines guarantee symmetrical upload and download speeds with 99.9% uptime SLAs. Fixed leased lines account for over 39% of UK business internet connections.
A 100 Mbps leased line costs £240-£320 per month on a 36-month term in urban areas. 500 Mbps costs £411-£673 per month, and 1 Gbps ranges from £437-£994 per month. CityFibre and alternative providers typically quote 20-35% below BT and Vodafone for equivalent products.
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Related Questions
Leased Line vs Broadband
How 1:1 contention on a leased line compares to shared broadband for business use.
Leased Lines
AMVIA's managed leased line service — dedicated, uncontended connectivity for UK businesses.
Business VoIP
VoIP performance depends on consistent bandwidth — a 1:1 contention leased line is the recommended foundation.