What is Transmission System 3 or T-3?

Like the T-1, T-3 is a common type of leased line used in telecommunications. Both T-1 and T-3 are typically rented by organizations at a monthly or yearly rate to connect geographically separated offices for private voice and or data networking. The North American standard for DS-3 operates at a signaling rate of 44.736 Mbps, or the equivalent of 28 T-1s. Besides being used for long-distance traffic, T-3 lines are also often used to build the core of a business network at its headquarters.

A T-3 circuit is a dedicated digital data carrier transmitted over copper or fiber optic wiring and is used to carry voice and data at speeds up to 44.7 million bits per second (44.7Mpbs). T-1's are most commonly installed as dedicated links between two office locations or from a customer to the internet.