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What's a T1 line, and how do I connect to it?


We are going on vacation and the condo where we are staying says they have a
T1 line. What, if anything is needed to connect my laptop to the T1 line?

A T1 line (also known as a DS1 line) is just a specific kind of
communications technology. It differs from DSL and Cable in a few respects,
which I’ll go over.

A T1 is nice, but it’s not nearly as impressive as it was in years past.

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A T1 is a data communications line that transfers data at a rate of 1.544
megabits per second, in both directions.

The T1 was originally designed to carry 24 digitized voice channels. You’ll
find T1s still in use for a lot of telephony in the United States today.

Naturally, with the internet boom, and since they were a) existing, well
understood technology, and b) carriers of digital data anyway, T1s started
getting used for data as well. Hence your condo.

T1s differ from DSL in a few respects:

  • DSL travels on the same copper wires that delivers your telephone. It’s an
    additional signal that you typically can’t hear. The advantage: no extra wiring

  • T1 is a dedicated circuit. That means that it requires a dedicated pair of
    wires. (It used to require four wires – a pair of pairs, one for up
    and one for down. Technically T1 is still a four-wire connection, but it is
    being delivered on a single pair these days as well.)

  • T1 is a specific speed, 1.544mbs, and it’s bi-directional. Both upload and
    download speeds are the same. DSL is more correctly referred to a ADSL or
    “Asymmetric”, meaning that the download speed is typically much faster than the
    upload speed, which is a decision that reflects most common internet usage: we
    download more than we upload.

In my experience a T1 at a vacation spot is better than average connectivity
these days. I typically test speeds when I travel, and quite frequently find
basic DSL speeds: 768kbs down and 128kbs up – in other words half the download
speed and less than a tenth of the upload speed of a T1.

Consumer cable internet speeds are often quoted as exceeding T1 speeds, and
that’s quite true. The difference is that a T1 is dedicated, whereas the cable
speeds are shared with an unknown number of your neighbors or other cable
internet subscribers in your area. (In your case the same will be true – I’m
certain the T1 be shared with the other residents in your condo.)

As it turns out, I have a T1 into my home. I’m on the fringes of DSL
availability, there’s no cable, and satellite internet has too many problems
for my usage.

Hooking up to a T1 should be no different to you than hooking up to any
internet provided by a facility: you’ll either plug into a hard wired ethernet
port, or there’ll be a wireless router provided by the facility.

Yes, the box which actually, physically connects to the T1 line will be
different and unique – much like a cable modem or DSL modem, but that should
already be there and in place. While it’s connected to a T1 on one side, it
should provide standard ethernet connectivity on the other, which your condo
provider should then have either wired to your unit’s ethernet port, or
connected to a wireless access point for your use.

In other words, you shouldn’t need anything special.

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3 comments on “What's a T1 line, and how do I connect to it?”

  1. Your article (presumably) is referring to the situation in the U.S.A. when you say that T1 speeds superceed typical DSL connectivity. In the UK the most DSL packages are at least 2Mbps down/512Kbps up, many ISPs offer 8Mbps/768Kbps as standard, and some are trying out ADSL2/2+ which offers upto 24Mbps/2.5Mbps. And the ADSL2 packages are not any more expensive that the ADSL equivalents, they’re just not as widely available, and in some cases if you’re too far from the exchange, slower or more unreliable. In this country, dedicated lines are often upto 100Mbps although they;re so expensive that they are very rare.

    In other countries I believe it is common for people to have internet connections of upto 50Mbps.

  2. Hi Leo – this is very useful information. Have you ever tried a high-speed satellite Internet service such as Wild Blue? There is no DSL in our area and the T1 line is incredibly expensive ($450/month). I’d appreciate any insight you have.

    IMO: the total bandwidth caps (or data transfer caps), along with the high delays sending to and from a satellite orbiting the earth, make it impractical (and often very frustrating) for anything but very simple and casual web surfing and email – in other words it’s not robust enough for me.



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