T3 Point to Point
A T3 connection is a point-to-point dedicated line that provides 672 64-Kbps voice or data channels or in other words 28 T1 lines. A T3 is used to transmit digital signals at 44.736 megabits per second and has enough bandwidth to transmit full-motion real-time video, and very large databases over a busy network. A T3 line would be installed as a major networking channel for a large corporation or university with high volume network traffic.
When you need more capacity, you often have to buy it in the next available increment, which may end up costing more than you want or can afford to spend. Worse yet, with current, "bursty" application requirements, the need for additional bandwidth can often be as temporary as it is critical. By providing flexible capacity, or "bandwidth on demand," service providers can help customers deal with variations in traffic, and with avoiding a high fixed monthly payment. True bandwidth-on-demand services should allow for a wide range in capacity.
Although anybody can purchase a burstable T3, this type of connection can be costly, even as costly as a full 45Mbps connections. Burstable lines can be found at their lowest cost at a colocation facility. At a colocation facility, or "colo", many users share a large OC3 or OC12 pipe. As a customer you will not have to pay for a the fixed cost of such a large pipe, but will have the benefit of being able to burst up to very high speeds if necessary. If you need the reliability of a large pipe fur busty traffic but don't have the capital consider a colo. If you have a steady volume and are consistent, you may consider keeping services in house and going with a T3 connection. Whether you are considering a colocation facility or a T3 to the door, make sure you use a broker to help guide you through the providers and plans available.
Dedicated Internet service will create easy access to high internet speed and will ensure that you can use DS3 lines. Additionally, the entire bandwidth is used for offsite backup of computer files overnight, when everybody is gone. That dedicated line may also be used for a web site server and an email server. If you encounter an internet conundrum, you can commandeer the line or a given amount of bandwidth for a particular need, such as downloading engineering drawings to a supplier. Keep in mind that you do not need to allocate Mbps full time for each employee. If you have a dozen to maybe two dozen people who need internet access, a T1 line at 1.5 Mbps might be all you need. At any given time, a user might think they have the line all to themselves. That may well be true for the fraction of a second they are loading a new page. DS3 transport may be a cost effective substitute for point-to-point transmission. It is also applicable for Surveillance Cameras, CCTV Systems, and VLAN Trunks. If a full DS3 line is more bandwidth than you really need, it is also possible to get Fractional DS3, which gives you a portion of full DS3 bandwidth at a lower cost.
A large company needs something more than a T1 line and could probably use a T-3 line powered by DS3 technology. The following table shows some of the common line designations: DS0 - 64 kilobits per second, ISDN - Two DS0 lines plus signaling (16 kilobits per second), or 128 kilobits per second, T1 - 1.544 megabits per second (24 DS0 lines), T3 - 43.232 megabits per second (28 T1s), OC3 - 155 megabits per second (84 T1s), OC12 - 622 megabits per second (4 OC3s), OC48 - 2.5 gigabits per seconds (4 OC12s) and OC192 - 9.6 gigabits per second (4 OC48s). Keep in mind that T-3 lines are used mainly by Internet Service Providers (ISPs) and large companies connecting to the Internet backbone and for the backbone itself.
