T1/DS1 broadband in the US uses two pairs of copper wire for transmission over telephone lines. An ordinary telephone line uses the DS0 transmission protocol, which carries 64 Kbit per second. A T1 line uses the DS1 protocol to combine the equivalent of 24 telephone lines for a total bandwidth of 1.536 Mbit per second.

T1 Internet providers in the US usually sell T1 lines to private customers in DS0 fractions. However, a small business will typically use a full T1 line to connect to the Internet and a larger business may use multiple T1 lines bundled together.

There are three primary factors to consider when you compare broadband services in the US:

1. Prices for T1 in the US vary in part according to your distance from the carrier’s Point of Presence. The further you are from the carrier’s POP, the more your T1/DS1 line will cost.

2. Major carriers usually own and operate their own networks, generally resulting in the best actual transmission speeds.

3. A channel bank is necessary to separate the DS1 data stream back into the 24 DS0 data packets. This device is relatively expensive to purchase or lease and represents a substantial investment for a small business.

Action Steps
The best contacts and resources to help you get it done

Locate the T1 carriers in the US that sell full T1 service

Use dedicated T1 in the US to provide high-speed Internet access for a group of employees. These services frequently include multiple static IP addresses and email addresses under your domain name.

I recommend: Comcast offers businesses connection speeds much faster than DSL with downloads up to 16 Mbps and uploads up to 2 Mbps. Speakeasy offers T1 service throughout the country. You can check for service availability on Speakeasy's website by providing your location information.

Find dedicated T1 providers in the US that specialize in business packages

Get T1/DS1 broadband in the US from a provider that can meet your needs now and scale your requirements as your business grows.

I recommend: EarthLink offers a symmetrical T1 business line so you can upload as fast as you download and guarantees 99.99 percent uptime. Cogent Communications offers dedicated T1 and T3 service to its Tier 1 backbone for businesses in more than 100 markets.

Look for a national carrier that provides T1 broadband access in the US

One advantage that a T1 connection has over DSL is that the speed of a T1 line does not decrease with distance. T1 users are therefore not dependent upon local providers.

I recommend: Megahits Internet uses leased lines to provide T1 access to businesses throughout the US. Tek Interactive Group provides point-to-point connections of up to T3 speed to businesses in the US.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  T1 broadband services in the US also are available as a channeled circuit to allow voice traffic on a portion of the channels. These voice channels may be plain T1 or Primary Rate Interface channels. Call centers frequently use PRI lines because they also carry signaling data such as Caller ID and Automatic Number Identification data.