T3 Pros And Cons
A fractional T3 still relies on the provisioning of a full T3 local access line to your end point, and that is costly. While there have been some price wars over the bellweather commodity in the marketplace, namely full T3s, largely fractional T3s have not participated in the same price decreases.
A fractional T3 line belongs to the Tcarrier family of telecom products, and as such is a tried and true means of getting Internet Access (particularly as opposed to the varying reliability of DSL, Cable and Satellite). It is this reliability that provides the main benefit to the fractional T3 line.
The main drawback quite simply is price. A fractional T3 line circuit is made up of 2 components: a fractional T3 port, and a full T3 local access line. The main challenge to the fractional T3 line and consequently the reason for its sporadic adoption is evident in it's description. As phone companies only provision full T3 local loops, the buyer of the T3 line ends up paying for last mile capacity that they can't use (since they've only bought a fractional T3 port). So, the end result is that the fractional T3 typically has a worse cost/benefit balance than a full T3. A 768k fractional T3 may cost 75% as much as a full T3, but only deliver 50% of the throughput.
A fractional T3 may still make sense in some situations. For instance, a company who needs reliability and not throughput. This may be true for many governmental services, services that need to be up 24x7 but do not need to be fast. In this situation $450 for a 768k nailed up line, may make more sense than paying $600 for a full T3. They save $150 a month and sure they give up speed, but they don't need it.
Companies that purchase fractional T3 lines that can burst up to a full T3. As fractional T3 lines come with a fully provisioned T3 local loop (which is the hardest of the 2 components of an Internet circuit to be provisioned), the fractional T3 can become a full T3 when the port is opened up at the carrier. Many carriers offer the option to increase port speed intra contract with notice, or several allow for a burstable port, which means that when a situation occurs that a company needs more speed on the fly, the carrier will allow for it. Be careful, though, as you can pay dearly for this option. If a company bursts past the fractional port speed often, the monthly bill will most likely be much more than it would have been for an ordinary "price protected" T3. The big pro is the Lower Overall Cost, and the con is there is less throughput that does not outweigh the cost savings = bad value proposition Many in telecom shy away from recommending fractional T3s as they aren't a great value proposition.
