What Are Leased Lines? A Buyer’s Guide

On the hunt for more information about high-speed internet connections? This guide aims to give you an understanding of one popular option: Leased Lines.

What are leased lines?

A leased line is a dedicated, fixed-bandwidth data connection. It allows data-hungry businesses to have a reliable, high-quality internet connection with guarantees of upload and download speed, uptime and resilience. “Leased” refers to the connection which is rented by the Internet Service Provider (ISP) directly to a business, resulting in a service above and beyond what standard broadband provides. Leased lines usually have these distinctive characteristics:


Leased lines must be symmetrical. This means they have the same upload and download speed.


Leased lines are  – by definition – uncontended connections, not shared with other users.

Point to point

They connect two points together, eg the ISP with a business location.

We’re all familiar with a standard internet connection. We get home, connect our phone, tablet or TV and start to stream, browse or download content. But when everyone in your area is doing the same thing, this can slow down the connection. This is because these connections are “contended” – bandwidth is shared amongst the users of a local area.

With a dedicated leased line, the bandwidth you require has been given to you and only you have access to it. This means that your connection won’t be hampered by peak times throughout the day.

If you own or run your own business, you’ll already be aware of the impact slow internet connections can have. Downloading or sending large files, VoIP conference calls – all can be interrupted by a poor internet connection.

Symmetric vs Asymmetric

As well as being uncontended, Leased Lines are also “Symmetric”. This means that the upload and download speed are the same, unlike traditional asymmetrical broadband, like ADSL, which often sees upload speeds hugely reduced in favour of high download speeds.

Symmetrical connections are incredibly useful for modern businesses, who are increasingly using cloud services that need reliable, fast download and upload rates. VoIP-based telephony is a key example.

How do they work?

A leased line uses exactly the same technology as fibre optic broadband. A fibre optic leased line works by sending pulses of light down a fibre optic cable. When you need to send data down a fibre optic cable, the equipment at either end is on the lookout for light – namely whether the light is on or off – representing the binary 0s and 1s of digital data. Equipment at one end will turn lights on and off to represent 1s and 0s, and the equipment at the other recognises this, records it and stores it back as 1s and 0s.

This data travels at the speed of light. As it is physically impossible for this to be any faster, the only limiting factor on speed is more often how quickly the equipment at either end can send or recognise light.

Where a leased line differs is this connection is leased to a business, so this connection to the ISP is unique to that particular firm, rather than shared with many thousands of others.

Leased Line Options For Businesses

Typically leased lines fall into the following categories. Note the confusing synonyms for each category!

Full Fibre (also known as “Fibre Ethernet” and “Ethernet Access Direct”)

The “big daddy” of internet connections: a direct, superfast ethernet connection over 100% fibre optic cables from the business premises to the ISP, delivering speeds of up to around 1Gbps (with 10Gbps currently being tested at time of writing). The fastest, most reliable, and, of course, the most expensive.

Ethernet in the First Mile (EFM – also known as “Ethernet Broadband”)

This connection uses the traditional copper network to deliver a connection to a business, then a full fibre ethernet connection from the exchange. Because of this, it is ideal for businesses who do not have a local fibre cabinet. It uses aggregated copper pairs to ensure a resilient service – if one set of copper fails, the other takes over. This means speeds are much, much lower than fibre, but the service is fully symmetrical and comes with resilience guarantees and SLAs. A cheaper mid price option.

Ethernet over FTTC (EoFTTC)

For businesses that do have access to local fibre-based cabinets, EoFTTC is similar to EFM but even cheaper. It uses a mixture of fibre and copper, with any drop off in speed due to the distance of a business from the local cabinet (as the last part of the connection from the cabinet is using copper pairs). Many providers offer this as a symmetric connection, but also capable of “bursting” or increasing the download speed well beyond the upload.

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How fast can I get?

The answer here is – obviously – very fast. With “standard” asymmetric fibre optic broadband, the maximum download speed most see is well under 100Mbps. As mentioned earlier, as this is asymmetric and contended, this will fluctuate and be affected by peak times throughout the day. The technical term for this act of sharing the same fibre optic lines between many is ‘multiplexing’ and is one of the factors that lets consumer broadband providers keep costs low.

With a fibre optic leased line, the speeds obtainable can be ridiculously fast. – packages are available delivering up to 10Gbps. As leased lines are uncontended symmetrical lines, you can even define how much speed you require from a leased line to suit your personal business requirements, meeting both your requirements for capacity and budget.

As an example, if you run a printing business, you may need to upload large graphic design work files to cloud storage for clients to review. Standard broadband services are usually asymmetrical, meaning the upload speed is nowhere near as fast as the download speed. You will be waiting around for large chunks of the day whilst your work is uploaded. However, with a fibre optic leased line, you can choose your dedicated upload speed to supercharge these transfers and allow you to get on with the important stuff. As the speed doesn’t fluctuate because of other users, you have an unwavering assurance that the speed is there when you need it.

Fibre optic leased lines are usually described in two parts, a line speed and a bearer speed. They are usually quoted like this: 20/100. The number before the slash is the line speed and the number after is the bearer.

The line speed is the symmetrical speed of what you experience when you use the connection – ie for both uploads and downloads.

The bearer is the maximum speed that the line can go up to. This means that in the future if your needs change (for example, your business grows) and your current line speed is lower than the bearer speed, you should be able to upgrade your bandwidth and pay just a bit more per month.

To use 20/100 as an example, the user can upload and download at 20Mbps (megabits per second). From here, they can upgrade in increments all the way up to 100Mbps, giving you reassurance that your connection can change with the needs of your business. The most common bearer sizes are 100Mbps and 1Gbps, with 10Gbps also being available (although not widely).

Do I need a leased line?

At a glance, businesses may be attracted to leased lines purely for speed – having superfast access to the internet in an age of increasing cloud service adoption makes a huge amount of sense. But ultimately speed is only one of the factors that make dedicated connections an essential piece of infrastructure for many businesses. Having a symmetrical connection makes the use of VoIP for business telephony and communication more reliable. The SLAs that come with a fixed connection also mean that any fault is often fixed within hours, not days or more. Essential for businesses with a high reliance on data for their day to day operations.

Ultimately, any business would benefit from a leased line, but those that we see with a particular need usually fall into these categories:

Speed-sensitive data transfer needs

Any business that absolutely must have fast data transfer for their day to day operations is a potential leased line candidate. This could include financial services firms that may need up to the second (or faster) intelligence and trading capability, or digital businesses that need fast response times on any customer interaction, for example with e-commerce or complex app infrastructure.

Heavy use of software as a service (SaaS) & cloud applications

Using cloud services as the backbone of business operations is now standard. Most businesses rely on CRM systems like Salesforce which are entirely cloud-based. Leased lines obviously help these firms have unfettered access to such services, but particularly where large datasets are being crunched in the cloud. This is particularly useful for any data-focussed tech businesses which need to actively monitor and analyse customer data in real time, or provide Software as a Service (SaaS) or cloud applications to clients themselves (like us for example!)

Use VoIP services

Any business that uses VoIP for their calls needs a stable connection. Although “standard” fibre broadband is more than capable of handling VoIP calls, when a business might have 20 or more concurrent calls at high quality, this needs a high speed, resilient and symmetrical connection. Because calls need fast response times from speaking (upload) to being spoken to (download), symmetrical connections are usually the favoured options for VoIP reliability.

What to ask leased line providers

Purchasing a leased line is not a snap decision and you’ll need to get satisfactory answers to a variety of questions. Here are just a few:

How will you assist me to get it installed?

You really need to view the installation of your fibre optic leased line as project. There are various queries to handle, appointments for surveys of your premises to be present for and engineer visits to be aware of. You need your chosen provider to have a team dedicated to managing installations whilst keeping a close eye on how things are progressing and clearly communicating updates to you as soon as they have them. There’s also often a lot of industry jargon involved, and you will rely on this team to explain things to you in plain English so you know what is happening every step of the way.

How will you support me?

Where is the support team based, and what hours do they work? How will you raise issues to them? Whilst a provider will not necessarily help you set up all the computers, switches and wireless access points in your office network, will they at least hold a handover call to help you plug your gateway or main switch into the termination equipment on site and ensure that your connection is up and working?

How resilient will the service be?

Dedicated fibre optic services are extremely reliable. Unlike copper based broadband services, they aren’t susceptible to environmental factors like electronic interference and water ingress in the network. And when they do go down, they are treated as a priority fix, usually with a five-hour target for a fix if there’s a total loss of service (versus several days for standard broadband services).

However, five hours will feel like an awfully long time if your whole business has gone offline. That’s why you should ensure that your provider includes some form of backup circuit to at least keep you online, even if it’s on a slower service. Ask whether there is a broadband backup included, and if you consider your connection as business-critical, ask whether they will even provide a second fibre optic leased line through a different route into the building. Another option could be to have a backhaul supplier to help make downtime even less likely.

How will any backup service be handled?

How do you switch over to any backup solution if and when you need it? The most basic way is that if your primary circuit goes down, you manually plug your equipment into the backup line. However, a much better solution is for the provider to ensure that this happens automatically, with a box on site handling the shift to the backup service within seconds of it detecting that your main circuit is down.

What visibility of the circuit will the provider have?

Ensure you know what type of service you are buying. You can purchase a fibre optic leased line as “wires only”. This has the benefit of you simply plugging in your equipment to the termination point and configure your network as you see fit. However, it will give your chosen provider very little visibility of your circuit, potentially slowing down support resolution times if you have an issue.

Alternatively, they may provide a managed router as part of the circuit, which will provide them with some visibility of your circuit that they can remotely monitor. They may even be able to set up some quality of service rules for you, allowing you to prioritise traffic that you think is important.

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What is the buying process like?

Once you have accepted a quote and completed the order form, a range of activities happen in the background to get a fibre optic leased line to your property.

First, have a very clear idea where in your property you want the circuit to terminate (most business premises have some sort of communications rack or room). As part of the installation, you will have a site survey where an engineer plans how to get a fibre optic cable from the exchange to your premises. As part of this they need to work out how much work is involved in getting the last bit of cable into your premises and to your chosen termination point. Changing your mind later on in the process where you want this termination point to be will cause delays and additional cost.

If you don’t own your property, talk to your landlord as soon as possible as their permission will be sought to install the circuit. Your landlord may insist on legal paperwork being drawn up (eg a wayleave) which can also slow the process and incur additional cost.

A certain amount of the installation cost will be covered as part of the setup of your fibre optic leased line. However, any cost above this amount will be charged to you, and is referred to as an “Excess Construction Charge”. A provider has no way of knowing what this may be when you place the order, although often they can give you a good (but not guaranteed) indication of whether any will apply to your installation. The good news is that whenever an Excess Construction Charge applies to an order, you will have 30 days to decide whether to accept and pay the charges, or cancel the order without penalty.

If you do proceed and additional work is identified at a later date you won’t be asked to shoulder the additional cost. So at least you know if you do proceed that you won’t suddenly get another invoice for additional work at a later date.

How long do they take to install?

Leased line installation times can vary and depend on several factors, such as what local infrastructure is already in place. Usually the results of the site survey give a reasonable indication of how long an installation may take, although there is never a guaranteed delivery date for your circuit because multiple parties (many of which aren’t involved in the installation) need to work together to deliver the circuit. For example, if a road needs to be dug up to install a new duct, applications to implement road closures or restrictions need to be made to the local council. These leased line orders may take many months to complete.

Occasionally, most of the infrastructure is in place, including available fibre optic cable into the building. These orders can complete within a few weeks. However, you’ll often hear timescales such as “45 to 90 working days” quoted for a new fibre optic leased line installation. This is much shorter for EFM due to the lack of new fibre needed to make the connection.

One way that you can assist getting your circuit provisioned is to work with your provider to provide quick turnaround times for any queries they send to you (as often the order is placed on hold until you answer). If the lead times cause you issues, you should ask your provider if they can provide any interim connectivity to your site (e.g. FTTC broadband) until your main service goes live.

How much do they cost?

The answer to this depends on a huge amount of factors, but very broadly, the lowest a business could expect to pay for full fibre leased lines is around £250 per month. This fluctuates based on location, speed, backup options, monitoring and more.

Common other leased line questions

What is a leased line?

leased line is a dedicated fixed-bandwidth data connection. The word ‘leased’ refers to the connection rented by the Internet Service Provider directly to a business. A leased line needs to be symmetrical, uncontended and point to point.

What are the advantages of leased lines?

Leased lines have many advantages for businesses. The main advantage is high symmetric speeds, meaning better connectivity and faster uploads and downloads. Leased lines are also very reliable and flexible. When you set up a leased line, you receive strong customer support and setup, for example if you choose our EoFTTC package, you receive 24/7 support from our expert team.

What are the disadvantages of leased lines?

A disadvantage of a leased line is that they can take a while to set up and install. The costs can also be higher than alternative services.

How fast is a leased line connection?

Leased lines start from around 10Mbps connections and scale all the way up to 10Gbps. Speak to our team about your requirements and they’ll provide a quotation.

What’s the difference between a leased line and broadband?

A leased line is a dedicated, uncontended connection between your premises and the local exchange. It’s only used by your business. Broadband isn’t a dedicated connection and is shared with other people.

Can I increase my leased line speeds in the future?

Once your leased line is installed, you might want to increase your speed if circumstances call for it. Provided you have space on the bearer line, you can increase your speed. Ask our team and they’ll arrange for the bandwidth to be increased.


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