Who Still Needs a T1?

With all the hoopla over copper and fiber Ethernet, plus new options in Cable broadband, that stalwart of business connectivity, the T1 line, is getting little fanfare these days. Does that mean that T1 is on its last legs? Or, is there a future for this proven telecom service?

Far from fading out, T1 is as popular as ever. New installations are being provisioned as you read this. The fact that T1 has been around for decades is one of its strongest features. That and the decline of T1 prices in tandem with competing Ethernet over Copper services are keeping T1 in the game.

So, who really needs T1? You do if you need professional grade dedicated bandwidth, secure point to point connections, or robust telephone trunking. That’s especially true if your business location is a bit off the beaten track. If you can’t get any wireline service other than plain old telephone, you probably can get a T1 line installed.

T1 has almost universal connectivity today. To understand how that can be when DSL and Cable rarely go past the city limits and Ethernet services are mostly found in business districts, we have to look back at why T1 was developed in the first place. We think of T1 lines as wide area network connections today, but in the beginning T1 was a telephone trunking system.

Prior to WWII, telephone companies connected to each other through analog lines on telephone poles or underground cables. Carrier telephony used a frequency division multiplexing scheme to load multiple conversations onto a single pair. In the 1950’s, Bell Labs developed digital multiplexing to replace the analog systems. The basic digital trunk was defined in the T-Carrier specifications. T-Carrier includes T1 and T3 lines.

The genius behind the design of T1 is that it runs on two pair of ordinary twisted pair copper. This is the subscriber loop connection that is installed in every business for telephone service. The wires are the same, but the signals on a T1 line are digital, not analog. While one copper pair can carry one business phone line, two copper pair can carry 24 phone lines or a digital bandwidth connection of 1.5 Mbps.

Another smart thing about the design of T1 is that provisions were made to boost the signal so that it can connect far flung locations. Not every business location is within a few thousand feet of a telco central office. Even analog signals fade out with distance. The much higher digital signal frequencies fade out much quicker. That’s why DSL is hard to come by. Unless you are close to the phone company CO, the DSL signal has little bandwidth capability left by the time it gets to your place.

The T1 support system was designed with a device called a regenerative repeater that can be installed in the line every mile or so to complete regenerate the signal. The noisy and faded input signal is boosted and reshaped so that at the output it looks like what comes out of the central office. Keep adding these repeaters and you can extend T1 service far out into the countryside.

If you have a business on the edge of town or in a remote location, you may still be able to get a T1 line for a reasonable price. The only real competition is two way satellite broadband. It works, but has very long latency times that make telephone service perform poorly, is subject to rain and snow outages, and has download limitations. If you exceed your quota, your speed will be reduced so that you don’t hog the limited resources of the satellite.

T1 has none of those problems. You get a rock solid 1.5 Mbps in both the upload and download direction. Load it full up with data transfers 24/7 or use what you need, the price is the same. Latency is negligible for most applications. In fact, T1 works great as a multi-telephone service or in the ISDN PRI configuration that supports most PBX telephone systems. You don’t have to get an Internet only data connections. T1 lines can be ordered between two business locations for a private line connection.

Is T1 the right service for your needs? Check T1 prices and availability instantly and compare with other options... if there are any that are suitable.

GigE and FastE Bandwidth Services

Bandwidth upgrades are a matter of course these days. Many companies are moving from T1 line speeds at 1.5 Mbps up to 3x3 Mbps or 10x10 Mbps Ethernet. Often there is little or no additional cost involved in doing so. But what if these bandwidth levels are still to low for your needs? Are there any opportunities at the 100 to 1000 Mbps level?

Carrier Ethernet is now the service to pursue at medium and high bandwidth speeds. These service levels have been dominated by DS3 or T3 lines at 45 Mbps and SONET OCx for higher line speeds over fiber optic cable. Ethernet bandwidth has a cost advantage for this need and also provisioning flexibility.

It’s common knowledge that low and mid-band Ethernet services are readily available over twisted pair copper wiring. In other words, the same telco wires that you currently use for analog business phone lines and T1 lines can also be used to transport Ethernet protocol. The service requires specialized equipment at each end and multiple copper pairs. This is Ethernet over Copper. Bandwidth levels vary from 1 Mbps on up 100 Mbps and beyond. A 200 Mbps service is available in some areas and a new 400 Mbps asymmetrical Internet access is being rolled out.

Most companies opt for Ethernet as a last mile connection to the Internet, metro or wide area MPLS network with bandwidth up to 50 Mbps. This is a direct replacement for their existing copper wire T1, bonded T1 or DS3 connections. By moving up the speed range to 100 Mbps to 400 Mbps, Ethernet can directly replace such fiber optic services as OC-3 at 155 Mbps and perhaps OC-12 at 622 Mbps.

All of this is done over up to 8 bonded copper pair at distances that don’t exceed a few thousand feet to a few miles from the telco central office. This is no problem in densely populated business districts, but as you move out into the burbs, small cities and rural areas, service becomes less available. Ethernet over Copper has a definite distance limitation.

Fast Ethernet at 100 Mbps may be available over copper, but Ethernet over Fiber is a better bet. The beauty of fiber is that once you have it installed and your building is “lit”, just about any bandwidth is possible. That includes FastE, of course, at 100 Mbps, GigE or Gigabit Ethernet at 1,000 Mbps and 10 GigE or 10 Gigabit Ethernet at 10,000 Mbps.

Ethernet over Fiber is available from traditional telephone companies, but it is also available from competitive carriers who have built their own IP-core regional and national networks with Ethernet as a standard service. These companies can bring Ethernet right to your building without having to lease any telephone company facilities. This gives them the ability to offer more bandwidth for less money. You may save half or more for equivalent service levels at the higher bandwidths.

A new wrinkle is Ethernet over Fiber offered by Cable MSOs. This fiber was bought and paid for by the Cable Television industry, but has so much extra bandwidth available that these companies are offering access to their fiber optic networks to businesses and other organizations that need anywhere from 10 to 1000 Gbps. That includes Fast Ethernet and Gigabit Ethernet at prices that are up to half the cost of other fiber providers.

The options are many and the prices are very attractive right now. There is lots of bandwidth to go around, which may not be true when the economy takes off again. If you need to speed up your networks, you can lock in some excellent deals. Check prices and availability for GigE and FastE bandwidth services appropriate for your business location.

50 Mbps Ethernet Takes on DS3

DS3 connections have been the traditional upgrade path for companies that have outgrown their T1 lines. But now there’s a newer technology service that gives you more bandwidth at less cost than DS3 and offers an easy upgrade path. That service is 50 Mbps Ethernet.

Let’s see why DS3 has become such a popular bandwidth service and why it will likely be replaced by Carrier Ethernet. A DS3, sometimes called a T3 line, isn’t simply 3x the bandwidth you get with T1. It is 28x the bandwidth. So if you have a 1.5 Mbps T1 line and you upgrade to DS3 service, your new bandwidth is about 45 Mbps. Those numbers are actually rounded so the multiplication isn’t exact. There are also overhead bits that must be assigned to manage a DS3 circuit.

As you might suspect, T1 and DS3 are in the same technology family. The tipoff is that DS3 is also called a T3 line. The “T” designation comes from “T-Carrier,” a set of specifications developed by the phone companies right after WWII to convert analog telephone trunks to digital. The T-Carrier specs are based on a 64 Kbps channel called a DS0 for Digital Signal level 0. A DS1 is comprised of 24 DS0 channels or 1.536 Mbps plus 8 Kbps for synchronization and maintenance for a total of 1.544 Mbps. That’s the T1 line speed.

A T3 line is also composed of DS0 channels at the most basic level. What’s so important about DS0 is that it is exactly the right size to carry one digitized telephone call. These channels can also be used to carry data packets instead of phone conversations. Package 672 DS0 channels together plus synchronization and maintenance bits and you have a DS3 running at 44.736 Mbps. That’s the T3 line speed.

T1 lines were designed to be delivered on 2 pair of ordinary twisted pair copper telephone wiring in a multi-pair binder cable. T3 lines were designed to be delivered on coaxial copper line or microwave transmission. Today, fiber optic cable is generally used to transport DS3 and higher bandwidth services. Bonded copper pair may get the job done over short distances, but is only found in densely populated cities.

The fact is that an upgrade from T1 to DS3 is a major move that requires equipment replacement, perhaps significant construction costs, and a considerable monthly lease price increase. Once you run out of bandwidth on a DS3, you need to move up to the next level of compatible services, OC3, at 155.52 Mbps.

What’s the competition for T1, DS3, OC3 and above? It’s a completely different family of network services called Carrier Ethernet, also known as Metro Ethernet. Carrier Ethernet has more in common with LAN Ethernet than it does with T-Carrier technology. T-Carrier was designed to transport telephone calls. Ethernet was designed to transport data packets. Yes, Ethernet can also be used to carry phone calls and does so exquisitely on converged voice and data networks. An Ethernet connection used to transport telephone traffic may also be called a SIP Trunk.

Now, let’s look at the replacement services for the old T-Carrier system. EoC or Ethernet over Copper is a direct replacement for T1 lines. There are two major benefits to going with EoC. First, the bandwidth is higher. A 2 or 3 Mbps Ethernet over Copper service replaces a 1.5 Mbps T1 line. The cost for both services is roughly the same. When you want to, you can upgrade to 10 or 20 Mbps over copper for more bandwidth.

The replacement for DS3 or T3 lines is 50 Mbps Ethernet. You get a modest increase in bandwidth and you’ll likely see a significant reduction in your monthly line services bill. It is not uncommon to pay half or less for 50 Mbps Ethernet compared with DS3.

You’ll need a fiber optic connection for either service. There is no standard fiber service that runs at the DS3 speed, so it is delivered on a SONET OC3 service using just a third of the available bandwidth. Ethernet is far more scalable. 10 Mbps, 100 Mbps and 1000 Mbps are standard network speeds, but you can get a wide range of increments between these levels. A good strategy is to order the Ethernet bandwidth you need now with an eye to easily upgrading to an incrementally higher speed as needed. The trick is to have an Ethernet port installed that can handle the maximum bandwidth you anticipate needing. If you have a 100 Mbps port, you can get 50 Mbps Ethernet out of that port now and then upgrade in steps to the maximum capacity of 100 Mbps later. Often, this can be done quickly and easily with a simple phone call to your service provider.

Are you anticipating a major WAN bandwidth upgrade, or are you already using DS3 service and either want more bandwidth or lower pricing? If so, get 50 Mbps Ethernet pricing and availability before you make any decisions. It’s a service that will serve you well in the coming years and offer a compelling cost savings as well.

Reduce Expense of T3 or DS3

You currently have or are considering 45 Mbps service using T3 or DS3. Before you re-sign or initiate a new contract, take a look at how you might save considerable expense in the process.

T3 and DS3 are often considered to be identical. They’re not, but they are very close technically. T3 refers to a specific T-carrier system created by Bell Labs. It can transport 45 Mbps of data in both directions (full duplex) or 672 telephone conversations. Do you have a T1 line now? It is part of the same T-carrier system. A T3 line can carry 28 T1 lines, to give you an idea about how much bandwidth 45 Mbps represents.

DS3 is the digital signal that rides on a T3 line. It is the specification that describes how you get all those telephone calls or T1 lines worth of data into that particular format of data stream. In other words, a physical T3 line transports a DS3 formatted digital signal. Sounds almost redundant until you learn that there are other ways to transport that DS3 signal. Most important is using a compatible fiber optic SONET connection. OC3, the lowest level of SONET fiber service generally available, runs at 156 Mbps and can transport three independent DS3 signals. A service provider might drop off one at your locations and another down the block. Or you might order an OC3 and break out the 3 streams yourself if you need that much bandwidth.

How, exactly, you get DS3 service to your PBX phone system or network router depends on what service providers in your area are offering. In dense metropolitan locations you may be able to get DS3 service via fixed wireless microwave connection, as well as fiber optic cable and perhaps coaxial copper wire. You’ll connect from the carrier’s termination to your DS3 router using a pair of copper coaxial jumper cables.

The fact that there are different delivery mechanisms for DS3 is one key to being able to reduce your telecom line expense. Not too long ago, the local telephone company was the only one offering this service. Now there are competitive carriers, each with their own fiber or wireless networks, who aggressively pursue high bandwidth customers. That has tended to drop the cost of DS3 service dramatically in recent years.

If you don’t specifically need DS3, but only the bandwidth level that DS3 can provide, there is another option you should seriously consider. That is metro or carrier Ethernet. At the 45 Mbps level, Ethernet may be delivered to your location by either fiber optic line or bundled copper pair. The copper solution only works within a short distance of the carrier’s nearest point of presence. But not everyone needs the full 45 Mbps. If your requirement is, say, 20 Mbps, then you may be able to get EoC or Ethernet over Copper over a wider area than is available for 45 Mbps service. You’ll also pay less, since Ethernet is priced per Mbps.

Ethernet is also a good choice for companies that have an immediate and anticipated need for more than 45 Mbps. It is a scalable service, so you can get 50 Mbps now and upgrade to 100 or 200 Mbps later without a major effort. Ethernet at these levels is delivered by fiber optic cabling. Fiber support an almost unlimited bandwidth capacity. Ethernet services are readily available at 100 Mbps Fast Ethernet, 1,000 Mbps Gigabit Ethernet and 10 GigE.

Does your organization have a need for increased bandwidth or would you like to check competitive prices before you commit to a new contract? Our Telarus consultants will be happy to get you a listing of bandwidths and pricing for DS3, Ethernet and other bandwidth services available for your location. As a bandwidth broker, Telarus works with dozens of carriers and can get you more competitive pricing than you could hope to get on your own. Best of all, this is a complementary service for all serious business applications.

The DS1 DS3 Relationship

If you are involved with business telecommunications networking or need to be, you have probably heard the terms DS1 and DS3 bandied about. But what do these terms really mean and where did they come from?

The DS in DS1 and DS3 stands for Digital Signal level. It is a designation that is used to specify the capacity of a digital line in the T-carrier system. You know the most popular T-carrier service as T1. Another popular service is T3. In simple terms, DS1 goes along with T1 and DS3 goes along with T3.

Now, let’s see what’s behind these DS levels and T-carriers. The history of this system goes back to the 1950’s, when Bell Labs recognized the advantage of changing from an all-analog telephone system to digital connections between telephone company offices. Digital transmission carries many conversations on few wires and eliminates the noise and cross-talk that were commonly heard on long distance calls at that time.

The most basic service is one two-way telephone conversation. That was made the most basic element of the T-carrier system and given the designation DS0 or Digital Signal level zero. A DS0 signal is the digital representation of a single voice call. It has a bandwidth of 64 Kbps formed by sampling the audio conversation at a rate of 8 Kbps with 8 bits of data. Those numbers are critical, because they represent the minimum bandwidth needed to give the same audio quality as an equivalent analog phone line.

If a DS0 is one phone call and consumes 64 Kbps of bandwidth, then what is a DS1? DS1 is a collection of 24 DS0 “channels” packed together in a bundle. That’s 24 separate telephone conversations. The bandwidth for this bundle is 1.536 Mbps. When you add 8 Kbps for synchronization, the total bandwidth is 1.544 Mbps. It’s commonly referred to as 1.5 Mbps. A T1 line is a DS1 digital signal package carried on a very specific physical network consisting of 2 pair of twisted pair telco wires with a defined voltage and waveform characteristic.

That’s what DS1 means. Now, how about DS3? If you bundle 28 DS1 signals, the equivalent of 672 DS0 voice channels, you get a DS3. The bandwidth of this signal is 44.736 Mbps, often referred to as 45 Mbps. A T3 line carries a DS3 signal on coaxial cable, although T3 service may also be sent by microwave.

Now, here’s where things get interesting. You can generate the DS digital signal protocol but not necessarily use a T1 line or T3 line for transport. In a process called multiplexing, multiple DS1 and DS3 signals can be combined and transported over fiber optic cable. The SONET fiber optic services were designed to directly accommodate this. The lowest bandwidth SONET service generally available is OC3, which carries 3 multiplexed DS3 signals with a total bandwidth of 155.52 Mbps. When the signals get to where they are needed, they are separated or demultiplexed to get back the 3 DS3 signals, which might be constructed of 28 DS1 signals each.

When used to transport data packets instead of telephone calls, the individual channels are generally invisible to the end user, although they exist within the T-carrier and SONET systems. DS1 and T1 can be said to have a bandwidth 1.5 Mbps. DS3 and T3 can be said to have a bandwidth of 45 Mbps. It is these numbers that you can use to compare pricing with competing telecom services , such as Metro Ethernet.