Fractional T1 Overview
T1 Rates for both T1 Voice and Data
Fractional T1 are one special kind of T1 lines. Unlike the most common 24 channel T1 lines that most of us are aware of, a Fractional T1 line uses only a few channels. Technically speaking, it is a combination of DS0’s.
Fractional T1 are lot cheaper than the full 24 channel T1. In case of a Fractional T1, only a part of a T1 is used, this enables the Telephone Companies to allocate same single line to multiple users. For example if a user `Tom’ has first half of the T1, and another user `Sally’ has the second half, both can work independently without any interference. In reality also, most of the small scale users never uses the full bandwidth of a T1 line.
All the equipments such as terminal equipments for fractional T1 are same as that of a regular T1. Speed for a fractional T1 is also same for Fractional T1, i.e., 1.544 MB per second.
Then how is Fractional T1 different from simple T-1? The path between customer permisses and the TelCo is a standard T1. But the end users are restricted to only those channels that are allocated to him. At the point of presence of carrier, that is the POP for carrier, all the individual T1’s are multiplexed to form a full 24 channel T1. At the TelCo office full T1’s are further multiplexed to T3 channels for connectivity to other places.
Since individual Fractional T1’s are multiplexed they need to be demultiplexed also. Demultiplexing is carried in the same way as the multiplexing is. At the remote location, when Demultiplexing is carried out individual unused channels are again stuffed with full T1 channels that are non functional.
This process may seem to be quite simple but in fact this is not the case. Terminating devices needs to be configured to ignore the unused DSO’s and drop all the signals if there are, present in them. Hence for a customer, it appears that he is using fully functional T1 line with 24 channels when in fact he was using only a fraction of it.
All said about the functionality of a Fractional T1 line.
Now how will you decide if a Fractional T1 line is suited for your needs or not.
If you think price is the only factor by which you can weigh your requirements then you are wrong. There are many other questions that you need to answer before deciding for a fractional T1.
While analyzing your requirements, take a larger scope, like your requirements after six months and after one year. Try to figure out how many employees from your company need broadband connection on daily basis. Among the frequent users, how many need dedicated high speed access and how many just need to do browsing.
How many online applications do you run and what is the nature of such applications. Are they susceptible to security risks and so on. What would be security measures that you need to deploy against any possible security threat. What is the primary nature of your service, voice, data, hosting etc…
This is only a fraction of questions that you need to ask yourself before going for a Fractional T1 connection.
