T1 Definition. What is a T1 line?

T1 definitions.  T1 lines and T1 definitions come in several variants.  T1, for example, is also known as DS1 (or Digital Signal 1).  You can also find it commonly written with a hyphen as in T-1 or DS-1.  T1 was developed by Bell Labs in the 1960s.  It is an acronym for "Transmission Level 1." A compilation of various definitions of T1 and descriptions that define T1 has been compiled and presented here for your convenience.

T-1 line.  "The common corporate link to the outside world, a T-1 line, offers speeds of 1.5 Mbps, and is able to max out at about 15 GB of information per day. According to Geoff Tudor, founder and senior vice-president for business development and product strategy at cloud storage company Nirvanix, if one assumes a corporate employee generates 3MB to 5MB of data per day, once you get over 300 employees sending their files to off-site cloud storage for backup, the T1 is tapped out. Over one of the fastest telcommunications options, an OC-48 line with speeds of about 2.5 Gbps, it will still take about an hour to send 1 TB of data.” T1 data per day. 1TB over T1. Network capacity per day. Multiple definitions of T1.  (Stacey Higginbotham, “Cloud Storage Could Mean Fat Pipes for All,” Business Week, April 3, 2009)

T1 dedicated line
“T1 is a dedicated line that has a much higher capacity than ordinary telephone lines. Capable of handling data at more than 1.5 Mbps, it can be used for purposes such as links to ISPs [Internet Service Providers] or linkages for private computer networks. The plus with T1 lines is the capacity is great enough to cover large volume usage. The downside is the expense, with costs (usually monthly fees paid to telephone companies) increasing with the distance covered.  But many businesses feel it's a worthwhile investment to support their information sharing needs.” A T1 line transmits data at speeds of 1.5 Mbps or more.  How much is a T1?  (Mark Rowh, “Cyberspeak: Let's get alphanumerical,” Office Solutions, October 1, 2001)

T-1 leased line connection.
“A leased-line connection for carrying data at 1,544,000 bits-per-second.  At maximum theoretical capacity, a T-1 line could move a Megabyte in less than 10 seconds.  That is still not fast enough for full-screen, full motion video, for which you need at least 10,000,000 bits-per-second.  T-1 is the fastest speed commonly used to connect networks to the Internet over 24 multiplexed 56 Kbps channels.”  (Russell Lee, “Telecommunications Network Links – What Type of Bandwidth is Available?," Information Engineering Technology, Department of Engineering and Computer Technology, College of Education, Distance Education, University of West Florida, Pensacola, Florida, July 18, 1997, Slide 8) 

T1 lines
“T1 lines are the standard for dedicated business Internet connectivity. They function as the veins and arteries that carry Internet traffic to its destination.  In spite of its limitations, T1 is a proven, reliable technology that currently meets the need for medium-speed, high reliability Internet access by institutions of many sizes, and it's likely to be around for a while.”  Shop T1.   (O'Reilly & Associates press release introducing Matthew Gast and his book "T1: A Survival Guide,” in “T1 survival--not just for the fittest anymore,” M2 Presswire, M2 Communications LTD, September 18, 2001)