The Difference Between Leased Line and Broadband Internet Connections

Many people ask us what the difference is between broadband and a leased line connections. Here are 9 of the key differences, to help you compare these options:

Difference Leased Line Broadband
Contention N/A Contended backhaul
Connection Speed Symmetry Symmetric Speeds Asymmetric Speeds
Downstream Speeds Up to 10Gbps typically ADSL2+: Up to 24Mbps (often less in practice)
FTTC: Up to 80Mbps
FTTP: Varies. Typically 100's of Mbps
Upstream Speeds Same as download speed. ADSL2+Annex M: Up to 2.5Mbps (higher in theory)
FTTC: Up to 20Mbps
FTTP: Varies. 10's of Mbps
Reliability High Average
Connection Metering Unmetered, Unthrottled connection Metered or 'unmetered' but subject to 'fair usage' with likely throttling
Installation Times 60-90 working days, typically 10-15 working days, typically
Cost Hundreds of pounds (cost varies by maximum speed) Tens of pounds (cost varies by maximum speed)
Support Levels Service Level Agreement provided. Probably 24/7 Support. Probably no Service Level Agreement. Support hours vary by provider.

CONTENTION: Leased line connections are uncontended, Broadband connections tend not to be

With a leased line, the whole path from the customer site to the leased line provider's core network is uncontended. In other words, 100% of the connection bandwidth the customer is paying for is reserved for their use at all times. Broadband tends to be contended, meaning that for at least part of the path between the customer site and the ISP's core network, the customer has to share the available network capacity with other customers.

This 'contention' cuts costs, as less backhaul bandwidth needs to be paid for, but it means that the connection's throughput may drop when other customers try to use the same 'over-contended' backhaul links at the same time.

SYMMETRIC CONNECTION SPEEDS: A leased Line's connection speed is identical upstream and downstream. Broadband has different speeds downstream and upstream

Broadband connections tend to be far slower upstream than downstream. Leased Lines offer the same connection speeds in both directions.

Typically, ISPs only advertise their broadband service's downstream speeds, so customers don't necessary realise that the upstream speeds are materially different - far, far slower.

Internet Leased Lines offer the same high speeds in both directions. This matters to offices, where the upstream connection often needs to sync data with cloud-hosted services, support outbound phone calls, enable staff to connect to their work PCs from home, transfer data to other sites on the corporate wide area network or backup data via the Internet.

MAXIMUM SPEEDS: In the UK, leased lines can typically deliver up to 10Gbps. Broadband tends to deliver far lower speeds

Throughout most of the UK, leased lines can be used to deliver 10Gbit/s of connectivity - that's 10,000 Mbps. Throughout most of the UK, broadband services can't even deliver one tenth of that.

RELIABILITY: Leased lines are more reliable than broadband, partly due to greater reliance on fibre-optic circuits, partly due to faster fault fix times

A DSL broadband connections - ADSL, ADSL2+, FTTC (which is powered in part by VDSL) - are provisioned using copper/aluminium wiring for part of the journey. Most leased lines are provisioned solely using fibre-optic cables. The latter are more reliable than the former, as they suffer less from electromagnetic interference and distance-related signal degradation.

Beyond the physical realities, there's also a big commercial difference. Leased Lines tend to come with Service Level Agreements that promise compensation if the service isn't available for more a certain percentage of the time.

CONNECTION METERING: Leased lines are unmetered, broadband connections may not be

Leased lines tend to be unmetered, meaning that the available bandwidth can be fully utilised, 24/7, with no restrictions. 

Broadband connections tend to be metered, or if marketed as 'unmetered' they tend to be subject to a 'Fair Usage' policy that means if you try to use your connection excessively you may find that some or all of your traffic is throttled (slowed down).

INSTALLATION TIMES: Broadband is far quicker to install than an Internet leased line... typically

Broadband typically takes weeks to be installed. Leased Lines take months. That's because broadband tends to largely piggyback on existing infrastructure that's already installed - reducing the need for civil engineering work.

Leased Lines differ from this as they tend to require new fibre-optic circuits to be installed. In general, this is more likely to require 'blowing' fibre and installing new fibre ducts. The service provider may need to seek a Wayleave from the building's landlord, and permission from the local authority to dig up the road.

COST: Leased Lines are far more expensive than broadband connections

Broadband connections are a lot cheaper than leased lines, because you're getting less. You're getting less backhaul capacity dedicated to you. You're getting slower fault fix times and fewer guarantees over fix times. You're often getting much higher staff:customer ratios. You're often getting less support (or no support) out-of-hours. You're getting less bandwidth upstream. You're getting less network usage before metering/'fair usage' policies apply. You're getting less pro-active connection monitoring. You're probably getting a cheaper lower-spec router.

That said, leased line prices have been falling, so many small businesses can afford leased lines now.

Leased line providers tend to help customers cope with the difference in price by recovering their installation costs over the life of a multi-year contract. This means that the typical leased line contract is three years long, in comparison to broadband where 12 month contracts or even rolling monthly contracts are far more typical.  

SUPPORT LEVELS: Leased Line services tend to come with business-grade support. Most broadband connections tend not to

Being a more expensive product, primarily for business, leased lines tend to come with better support levels than broadband. Typically, there will be a 24/7 support line, with much higher levels of support staff per customer than would be available to home or business broadband customers.

Leased lines tend to come with a Service Level Agreement, whereas Broadband tends to be provided with no such guarantees. Some business broadband services do offer 24/7 or extended hours support and SLAs, but the fix times tend to be far longer than is the case for leased lines.

Often, internet leased lines will be monitored proactively, whereas broadband connections will not be monitored at all. In the former case, your ISP may notice something is wrong before you do. In the latter case, it will tend to be your responsibility to spot that's something is wrong and report it to your ISP. Only then will troubleshooting begin.

If you'd like to learn more about the difference between broadband and leased line, click on the link to your left. That article's focus is slightly different to this one's. We cover over twice as many differences, and focus more on 'real world' differences, including commercial considerations.