A leased line is a dedicated telecommunications circuit that a business rents from a carrier to link two locations, or a location and an ISP, with fixed capacity that is not shared with other customers. It is also called a dedicated internet access (DIA) circuit when it connects to the internet.
Why it matters
Consumer broadband is usually contended and asymmetric, with the provider promising only "up to" a speed. A leased line gives the same bandwidth in both directions, and it typically comes with a service level agreement (SLA) covering uptime, latency and repair time. Businesses that host servers, run voice or depend on constant connectivity pay a premium for that predictability. Delivery is commonly over fiber, and capacities range from a few Mbit/s to 10 Gbit/s and more.
Example
An office buys a 200 Mbit/s symmetric leased line with a 4-hour fix target. A speed test shows about 200 Mbit/s both up and down at any time of day, and the SLA gives service credits if outages exceed the agreed limit. A 200 Mbit/s consumer plan might deliver 20 Mbit/s upstream and slow in the evening.
Common mistakes
- Assuming a leased line includes a backup path; resilience often needs a second circuit.
- Ignoring installation lead times, which can run into weeks or months.
- Confusing it with MPLS, which is a carrier-managed shared network.
Related
Get notified when this term updates
Plus occasional practical tips on uptime and monitoring, nothing else. Unsubscribe anytime.
This page is general information written by our editorial team and updated when documentation changes. Servers and providers differ, so test changes safely first. See our editorial policy and disclaimer.