Friday, July 06, 2012

Connectivity Expansion With Multiple T1 Lines

T1 lines have been excellent network connection options for decades. They still are if your bandwidth needs are modest. But what do you do when 1.5 Mbps just won’t cut it anymore? Is it time to say goodbye to your faithful T1 line?

Multiple T1 lines mean higher bandwidth services...Wait! Not so fast. Those T1 lines have a lot of untapped potential. It’s simply time for a technology upgrade.

That upgrade is called “bonding.” As the name implies, bonding is a process of combining the capacity of multiple T1 lines so that they act as one larger bandwidth service. This is typically done using a managed router. The carrier’s side of the router has interface cards for two or more separate T1 lines. You plug into a single connector that delivers the combined bandwidth of all those T1 lines.

What level of bandwidth is reasonable to expect? Dual bonded T1 gives you 2 x 1.5 Mbps or a total of 3 Mbps. Triple bonded T1 produces 4.5 Mbps. Quadruple bonded offers 6 Mbps. You can bond 5 T1 lines for 7.5 Mbps, 6 lines for 9 Mbps, 7 lines for 10.5 Mbps and 8 lines for 12 Mbps. Generically, this is designated as NxT1 where N is the number of T1 lines involved.

Not all of these options will be available in any particular area. Two factors determine how much bandwidth you can get with multiple T1 lines. First is the equipment available at the central office where your telephone wire bundle terminates. This bundle consists of many twisted pair, perhaps as many as 50 pair, all in a single cable. That cable runs underground or overhead on telephone poles to get from your building to the telco office. Multi-pair bundles are almost always installed to business locations because they very often need multiple line telephone service.

The equipment is important because there have to be connections at both ends of the copper cabling for the bundling to work. There is a managed T1 router with multiple line cards installed in the telecom closet in your building. There is a complementary piece of equipment in a rack at the central office to connect to the far end of those T1 lines.

Assuming that the carrier equipment is in place, the limiting factor in bonding multiple T1 lines is the availability and quality of the extra copper pairs in the bundle. Some cables may not have 8 unused pairs available. That’s especially true if the building supports multiple businesses, all using several phone lines or more. Other cables may have vacant pairs, but they have bridging connections or quality problems that don’t support reliable data transmissions. In some cases, adjacent pairs may have too much cross talk to both carry T1 signals without data corruption.

A final issue is cost. The price of T1 lines has come down dramatically over the years. If you haven’t checked pricing since you signed your contract and renewed it a couple of times, you may be shocked at how little it costs to maintain T1 service these days. Some companies find that they can easily upgrade to 2xT1 or 3xT1 and not pay any more in monthly least costs. Otherwise the cost of bonded T1 service is the single T1 line times the number of lines you want to connect. There’s no real economy of scale.

If you still need 10 or 12 Mbps but the cost of 7 or 8 T1 lines is too much for the budget, you aren’t out of luck. A competing technology called Ethernet over Copper (EoC) can typically give you twice the bandwidth for the same dollar. EoC uses the same copper pair you would otherwise use for T1 but can support higher bandwidths, perhaps 15 Mbps, 20 Mbps or more. Unlike T1, Ethernet over Copper is distance sensitive and only works well for locations near the CO.

Would you like to upgrade to higher bandwidth business connections without the expense or inavailability of fiber? Get pricing and bandwidth options for multiple T1 lines and competitive EoC options now.

Click to check pricing and features or get support from a Telarus product specialist.

Note: Photo of multipair cable courtesy of Wikimedia Commons.

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