What Is A Leased Line?

Date First Published: 20th May 2022

Topic: Computer Networking

Subtopic: Network Setups

Article Type: Computer Terms & Definitions

Difficulty Level: 5/10

Learn more about what a leased line is in this article.

A leased line, also known as a dedicated line or a private circuit, is a telephone or data line that is rented for use by one individual person. It is when an ISP allows a single customer to rent an entire telephone or data line for their own use, meaning that the internet connection cannot go down due to another customer using a lot of data or at busy times. The customer or business is directly connected to the distribution point or telephone exchange.

Bandwidth is not shared between multiple customers and this guarantees high upload and download speeds as well as increased uptime, reliability, and support, but it is also an expensive option and leased lines may take a long time to install. They are much more expensive than ADSL connections, which have higher download than upload speeds, since they are asymmetrical. The high cost of leased lines often discourages people to rent them and choose alternative fast options. An example of a common leased line is a T1 data line.

Note:

Leased lines run from two locations. For example, a leased line may run from an office of a business to an ISP data centre. Leased lines can span a short or long distance.

Speed

Leased lines are much faster than ADSL. Standard asymmetric fibre optic usually provides speeds of under 100 Mb/s. The speed can vary based on how many customers are customers and during busy times. Multiplexing is the term used for sharing the same fibre optic lines with others. A fibre optic leased line delivers very fast speeds. Speeds of up to 10 Gb/s are possible. It is possible for businesses and customers to choose how much speed they require from a leased line, depending on their requirements and budget.

In addition, the upload speed of leased lines is much faster. Most broadband services are asymmetrical, meaning that the upload speed is much slower than the download speed. If large amounts of data need to be uploaded to a server, it will take a very long time. Leased lines will allow customers and businesses to choose their dedicated upload speed, allowing them to upload data much more quickly.

The most common reason for a business to rent a leased line is due to speed and time-sensitive communications, such as VoIP, streaming, and video calls. Businesses that rely on VoIP on a daily basis and need a fast response (download) and speaking (upload) times may rent a leased line.