Bonded T1. Before You Upgrade to T3, Take a Look at Your Options

Bond… Bonded T1.
Before You Upgrade to T3, Take a Look at Your Options

In my previous search for residential T1 lines, I came across the option of bonded T1 technology. Basically, a bonded T1 line is more than one regular T1 line “bonded” or joined together to increase bandwidth speeds. Inverse multiplexing (IMUX) divides traffic from a single bit stream among multiple circuits. This means that traffic from a single source is distributed across the individual circuits to make use of, say, the 3Mb of bandwidth from two bonded lines.

A full T1 line provides approximately 1.5Mbps of broadband speed. You would estimate an additional 1.5Mbps for each extra T1 line in a bonded line, meaning 2 lines equate to 3MB, 3 lines equals 4.5, and so on. With that said, I need to point out that the T1 lines must also run into the same end router, meaning they must run through the same Internet Service Provider (ISP) in order to bond them. Having two lines from different ISPs may load balance the data flow, but it won’t be a true bonded line with exponential results in bandwidth. Plus, not every company offers bonded T1, so snoop around to find out what ISP best suits your needs.

Why have bonded T1? Well it’s always a matter of dollar signs. Most corporations expanding beyond the limits of their T1 service choose to move onto fractional T3 lines, which deliver about 3 to 22 Mbps. Bonded T1 is a viable alternative because the costs are usually cheaper. An ISP I found advertises that their bonded T1 lines are 75% CHEAPER than a fractional T3. Prices vary, but the average price of a fractional T3 line is fixed around $3,500 a month.

Let me provide a charge of bonded T1 pricing:

# of T1 Lines Bonded	Mbps	Price ($)
2	3	840
3	4.5	1130
4	6	1420
5	7.5	1700
6	9	1970
7	10.5	2230
8	12	2480

A T3 line would cost about $4600 a month, and $3,500 for 10Mb Fractional T3.

Bonded T1 lines are redundant, meaning if any lines fail at the moment, the data will be piped through the other lines in the bonded line to provide consistent data flow.

The maximum of lines bonded is usually around 4 T1s, although some have gone as far as 8. However, if you go beyond 4 bonded T1's it makes much more sense to start looking at a fractional/burstable DS3. Take into consideration that 8 bonded T1s would get you about 12Mbps. Those of you who need heavy-duty bandwidth should seriously consider getting a T3 line, which provides 45Mbps worth of speed.

Corporations who jump from a dual bonded T1 speed to a 6 Mbps T3 will typically incur a larger monthly price than that of just adding more T1s. The draw to T3 is found in its scalability properties. Upgrades are a matter of resizing the port, which will rarely take more than a few days, and the T3 line can go up to 45 Mbps. As users scale above 9 Mbps, the T3 begins to become the better-priced option.

Hopefully this helps those of you out there who are looking for more than a regular T1 can offer, but something cheaper than a T3. It’s really up to what you think your company needs.