11.23.04
T1 Economics
A T1 data connection is a channelized circuit divided into 24 time slots. Each time slot has 64kbps of data capacity. A full T1 circuit has 1.536mbps of data capacity (64 x 24)
A fractional T1 is, as you likely guessed, anything UNDER a full T1 of data capacity.
Fully utilized, a T1 on an ISP's router should provide capacity for around 3 customers in this fashion:
Time slots 1-8 = 512kbps, 9-16 = 512kbps, and 17-24 = 512kbps.
That is a typical data amount for customers. Other popular rates are, for example, time slots 1-12 and 13-24 for 768kbps of data each, or 1-16 for 1024kbps and 17-24 for 512kbps.
Now, what happens when orders come in for 704kbps (using up only 11 time slots) or better yet, the famous 7 channel/448kbps genius move? Things get in a word....jacked up! Sorry, that was two words.
Unless more orders like "these" come in, it will nearly impossible to completely use the available space on the T1 because most providers don't sell single 64kbps timeslots and most people wouldn't even consider getting that little amount. To further this problem, a T1 is a member of a much larger circuit called a T3 or DS3. That T3 has 28 of these things on it. Over the span of the T3, you can almost find enough "remnant" capacity to fill at least one whole T1.
If capacity can't be found, and all the T1s are filled up, guess what...you've got to get a new T3....an interface for the router....line card for the cross-connects....and man hours to wire it all up. All because one more little channel of data wasn't ordered.
3:08 pm in teknikol pepole | 1 person viewing0 ramblings so far