“Do we need a leased line?” is one of the more expensive questions a growing business can get wrong in either direction. Buy one you do not need and you are paying several times over for capacity you never use. Run a revenue-critical operation on consumer broadband and you find out what an unbounded repair time feels like. The distinction is not about speed. It is about what is contracted.
What each product actually is
Internet leased line (ILL)
A dedicated circuit between your premises and the provider’s network, usually delivered over point-to-point fibre. Its defining properties:
- Uncontended. The advertised bandwidth is yours, 1:1. You are not sharing an access segment with other subscribers.
- Symmetric. The same capacity upstream and downstream, always.
- Contracted. A service level agreement with an availability target, a defined mean time to restore, and a financial remedy when they are missed.
- Publicly addressable. A block of static IP addresses, with reverse DNS you can set. No carrier-grade NAT between you and the internet.
- Monitored. The provider watches the circuit and typically knows it is down before you call.
Business broadband
A shared access service — usually FTTH — sold with business-oriented terms: sometimes a static IP, sometimes faster support response, sometimes a light SLA. The underlying network is still shared, and the service is best-effort: the provider will restore it as quickly as it reasonably can, with no contractual clock.
The quality of business broadband varies enormously, and most of the variance comes down to the provider’s contention policy rather than the headline speed. A well-engineered shared network can outperform a badly run one at three times the advertised rate — which is what oversubscription is about.
The difference that justifies the price
Both products can deliver 200 Mbps. Only one of them promises to.
A leased line typically costs several times more per megabit than business broadband — occasionally an order of magnitude more. You are not buying megabits. You are buying three things: guaranteed capacity at the worst hour of the worst day, a repair commitment with a number on it, and someone contractually obliged to care. If none of those three would change a decision you make, you are buying an expensive way to get the same megabits.
Signals that you have outgrown broadband
- Revenue stops when the link stops. Point-of-sale, dispatch, booking, trading, telemedicine, a support floor on VoIP.
- You host something people connect into. A VPN concentrator, an on-premises server, remote desktop for staff, a site-to-site tunnel between branches. This needs stable public addressing, and it needs upstream capacity.
- Sustained concurrent upload. Media production, offsite backup of large datasets, many cameras streaming out, an office where fifty people are all on video calls. See why upload capacity is the binding constraint.
- You have contractual obligations of your own. If you owe a client an SLA, you need one underneath you, or you are absorbing risk you have not priced.
- Regulatory or audit requirements that specify dedicated connectivity or documented availability.
Signals that you do not
- Your work is browser-based SaaS, email and occasional calls, and a two-hour outage is annoying rather than expensive.
- Staff can tether to mobile data and keep working.
- You have fewer than about a dozen simultaneous users and no inbound services.
- Your current connection has never actually failed you — as opposed to feeling slow, which is usually a different and cheaper problem to fix.
The option most people skip: two of the cheap thing
Between “one broadband line” and “one leased line” sits an arrangement that is often the best value in the range: two independent broadband connections from different providers, terminated on a dual-WAN router or SD-WAN appliance that fails over automatically.
This buys you resilience against the most common causes of a long outage — a cut in one provider’s last mile, a fault at one exchange — for substantially less than a leased line. What it does not buy you is a contracted restoration time, guaranteed capacity, or a single party accountable for the result. Redundancy and a service level are different purchases; conflating them is a common and costly mistake.
The best-of-both configuration, where the budget allows, is a leased line with a broadband service as its backup path. Make sure the two genuinely take different physical routes into the building, or one backhoe removes both.
What to check in a leased-line quote
- Availability target and how it is measured — annually, monthly, per circuit, and excluding what. This wording is where the value lives: how to read an uptime SLA.
- Mean time to restore, as a committed number with escalation points — not “best effort”, and not measured from when a technician was dispatched.
- Last-mile media and route. Fibre or radio? Aerial or ducted? Shared duct with anything else you buy?
- Static IP allocation, whether reverse DNS delegation is available, and the cost of a larger block later.
- The remedy when the SLA is breached, and how it is claimed. Automatic credit or a form you have to file within seven days?
- Burstability — can you exceed the committed rate temporarily, and on what terms?
ValoNet sells both sides of this line: FTTH and business broadband, and dedicated leased-line connectivity with capacity up to 10 Gbps on the enterprise tier, behind a 99.9% uptime SLA. Which one a given business should buy is a question about that business, and the arithmetic above answers it better than any brochure.