Copper First, Then Fiber Bandwidth Solution

What do you do when you really need to get your business connected, but fiber optic service installation just isn’t going to happen soon enough? One option is to adopt a two-stage process that gets you going now and then steps up to the bandwidth you really need when it's available. The key is utilizing two different technologies to take advantage of their strengths.

Fiber optic bandwidth, either SONET or Ethernet, will get you the bandwidth you need for any conceivable application. The low end starts around 50 or 100 Mbps and goes up to at least 1 Gbps, with many locations eligible for 10 Gbps Ethernet (10 GigE) or OC-192 SONET (10 Gbps).

Copper bandwidth, either T-Carrier or Ethernet, will get you the bandwidth you need much faster. That bandwidth, though, is going to be a lot slower than what you can get with fiber. T1 lines are reasonably priced, available almost anywhere, and can be installed in a matter of weeks. The base bandwidth is 1.5 Mbps. Not enough to even consider? Then multiply that bandwidth by bonding additional T1 lines. You can get 12 Mbps over T1 by bonding 8 T1 lines together to act as one big bandwidth pipe.

An alternative is Ethernet over Copper. This service uses the same twisted pair copper telco lines as T1, but has a more efficient modulation scheme. You can easily get 10, 20 or 30 Mbps using 8 copper pair. EoC technology trades off bandwidth and distance, unlike T1 which is 1.5 Mbps no matter how far you are from the central office. If you are within a mile from the CO and the office is properly equipped, you may be able to get 50 to 100 Mbps Ethernet over Copper. Those speeds are starting to get competitive with OC-3 (155 Mbps) and Fast Ethernet (100 Mbps).

If fiber is what you really want, you could be looking at months to complete the installation. That’s especially true if the metro fiber is running down one side of the highway and you are on the other side. Or, if the nearest fiber connection is blocks away in the city. It’s much faster if your building is already “lit” for fiber optic service, even if you are not a subscriber. Adding customers to an already existing fiber installation is relatively easy. It’s also reasonably fast and easy if there is a fiber lit building next door.

You’ve got the idea that fiber installations aren’t a given for any particular business location. Not yet, anyway. Some estimates are that less than 25% of all business buildings are lit for fiber optic service. On the other hand, nearly 100% of all business buildings are already being served with copper telco lines. Most often these are multi-pair bundles installed for multiple line telephone service. Unused pairs can be quickly pressed into service for Ethernet over Copper or T1 line service. After all, they are already hooked up at both ends of the cable run.

With that in mind, here’s a two step solution that I’ve seen work when a business needs both high bandwidth and fast installation. What you do is work with a carrier that has both copper and fiber technologies available. That’s fairly common now. Have them install bonded T1 or Ethernet over Copper at the highest bandwidth they can quickly install. At the same time, place an order for fiber optic service at the bandwidth you really need. The trick is to get an agreement that you can drop the copper service without penalty once your fiber service is turned up.

By working out this type of arrangement, you may get as much as half the bandwidth you need on a fairly quick schedule. By the time you get used to doing business on the copper lines, your fiber will be cut-in and it will seem like someone opened the bandwidth floodgates. You’ll only have to pay for one service at a time, although you might think about it and keep the copper connection as a backup for your fiber if the budget permits.

Do you have a situation that needs special consideration for connectivity? There may be more options than you think. Get consultation and bandwidth option prices and provisioning times now.

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.

What Is a DS3 Circuit Or T3 Line?

Companies that have outgrown their T1 lines often upgrade to DS3 bandwidth. Let’s take a look at what DS3 has to offer, how it relates to T3 lines, and recent competition from Ethernet over Copper services.

DS3 stands for Digital Signal level 3. The specification for it is found in the T-carrier standards developed by Bell Labs for the telephone industry. The way it works is that DS0 is the smallest unit with a bandwidth of 64 Kbps. That’s just the right size to transport one digitized telephone call using PCM (Pulse Code Modulation), the original digital phone standard. You combine 24 DS0s to create a DS1 that runs on a T1 line. DS3 is the equivalent of 28 DS1s or 672 DS0s.

You’ll often hear DS3 referred to as T3, like DS1 is called T1. The fine line of difference between DS3 and T3 is that DS3 refers to the actual structure of the data stream and T3 refers to the physical transmission layer. Most of the time, they are treated as equivalent. The reason that the digital signal has its own definition is that you can multiplex DS3 as well as DS1 to make much larger bandwidth services. At the far end, you can then demultiplex the signals to recover the original DS3 or DS1.

Combine the 672 voice channels plus the bits needed for synchronization and line maintenance and you have a bandwidth of 44.736 Mbps. That’s commonly referred to as 45 Mbps. You can order DS3 as a telephone trunk line if you have a high capacity phone systems like a PBX serving a major corporation. You can also order DS3 as a data line with one big chunk of bandwidth, namely 45 Mbps.

If you order a T3 line or DS3 service, it will be delivered to you on a pair of 75 ohm coaxial cables using BNC connectors. Look at a DS3 router card and you’ll see the connectors, one for receive and one for transmit. Some cards support more than one DS3 connection so you’ll see multiple sets of connectors.

The coaxial cable used to connect your DS3 router can be no more than 450 feet in length (only 225 feet if using small diameter coax). That’s fine for connecting to the telco demarc in your building, but how does the DS3 get to the central office?

The actual provisioning of DS3 services can be via fixed wireless transmission or SONET fiber optic service. DS3 can be easily encapsulated into a SONET STS-1, as they are both telco standards designed to be compatible. An OC-3 service can carry 3 STS-1s for 3 DS3s.

What if you are not in range for fixed wireless and there’s no fiber in the area? Are you stuck with the 1.5 Mbps T1 bandwidth? No, not really. T1 lines can be bonded to create larger bandwidths. This works well up to 10 or 12 Mbps. Bridging the gap between bonded T1 and DS3 is Ethernet over Copper. This technology also uses multiple copper pair instead of fiber strands, but can deliver much higher bandwidth than T1 technology.

Ethernet over Copper (EoC) bandwidth starts at typically 2 Mbps and goes up to 200 Mbps in some areas. This not only gives you a way to grow your bandwidth incrementally beyond T1, but may delay fiber installation indefinitely. The one limitation of EoC is that it is distance limited. How far you are from the office where your copper bundle is terminated determines the bandwidth that is possible. That office also needs to have EoC equipment available.

Have you outgrown your T1 line service or have an immediate business need for bandwidth in the 45 Mbps range? If so get pricing and availability of DS3 bandwidth services, including Ethernet over Copper if available.



Photo of BNC connector courtesy of Wikimedia Commons.

Boost Ethernet over Copper Speed in 60 Minutes

The new Carrier Ethernet services are known to have a scalability advantage over legacy T-Carrier and SONET telecom services. Soon, it will be possible to crank up your bandwidth in as little as an hour with nothing more than a phone call or Web portal login.

The name of the game in business today is agility. There’s so much uncertainty and day to day volatility in the commercial environment that traditional planning cycles can’t keep up. One indicator of these changing business needs has been the meteoric rise of cloud computing services. The cloud is more than just a way to reduce staffing and avoid large capital investments. Cloud services are offered on an “as needed” basis. If you need more servers or bandwidth, you can get them quickly and easily.

What works in the cloud can also benefit bricks and mortar operations. All companies have a need for WAN bandwidth, either to the Internet or point to point to other facilities. Many companies have a larger need for mesh networks to interconnect multiple branch offices, stores, regional warehouses and the like. Even small concerns with a single office location need voice and data connections to the outside world. Wouldn’t it be great if you could buy the bandwidth you need right now, but respond in a flash if your needs suddenly increased?

That is possible to some extent and will soon be expanded with Ethernet over Copper. EoC, as it is also called, gives you transparent Ethernet connectivity from your LAN to the Internet, a MPLS-VPN network or point to point to another location. Technically, EoC uses dry copper pair (ordinary telco wiring) to transport Ethernet packets from a nearby central office to your location. Two or more pair are employed. The higher the maximum desired bandwidth, the more pair are connected.

There are two characteristics that are making Ethernet over Copper a highly popular connection service for business. First, the implementation uses the same type of copper wiring as you have for T1 lines and multi-line telephone service. Chances are that you already have the required multi-pair binder cable installed and in use. Second, pricing of Ethernet over Copper services is decidedly lower than equivalent T-1 or bonded T-1 line pricing.

MegaPath, a major competitive carrier and leader in Ethernet over Copper deployment, has been offering EoC services from 1,900 central offices where it has co-located the required equipment. They offer speeds up to 3 Mbps, making EoC highly attractive as a T1 replacement service. Over the next year, they will upgrade their terminal equipment at these and additional offices to offer EoC from 2 to 20 Mbps. In special cases, they will have the ability to go all the way up to 90 Mbps with a circuit card change.

The ultimate in flexibility is also on the way. MegaPath is planning to offer an on-demand upgrade from 3 Mbps to as high as 20 Mbps in a little as 60 minutes with no more than a phone call. The next step will be a customer self-service portal so that you can make the change yourself online. No longer will you have to keep extra bandwidth capacity on hand “just in case.” Order what you need for your current operations and then request a rapid upgrade when the need arises.

Could your office, retail store, restaurant or other business benefit from better bandwidth pricing and more flexibility? If so, check Ethernet over Copper pricing and availability. It could be a valuable competitive edge in these uncertain times.

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.

What Leased Line Service Providers Offer

Most businesses get their telecommunication services from leased line service providers. That includes telephone, Internet, and point to point line services. You probably have some of these contracts yourself. But do you know about the cost reductions and all of the new services that have become available recently?

The nature of telecommunications services has changed dramatically in recent years. The two biggest changes are cost savings that come from a flurry of new competitive service providers and the introduction of new technologies that offer additional services.

You can still get most of the telecom services that were available a decade or so ago. The most popular line service is T-carrier, especially the T1 line. T1 is a telephone company technology and comes in several flavors. The original use was a digital trunk to carry multiple phone calls between telco switching centers or into a multi-line business phone system. An upgraded version of the T1 telephone line is called T1 PRI or ISDN PRI. It gives you up to 23 outside phone lines plus a data channel for dialing, switching and Caller ID. Nearly every PBX phone system and many key telephone systems can be easily configured to use T1 PRI.

Another use for T1 lines is to provide point to point connectivity between two business locations. A point to point T1 line offers 1.5 Mbps in both directions simultaneously. If you need more bandwidth than this, you can get bonded T1 service that combines multiple T1 lines up to about 10 or 12 Mbps total.

A related service is the T1 access line. This is a last mile connection to a larger network. At one time, the larger network was called Frame Relay. Nowadays, MPLS networks have taken over this role of connecting business locations on a regional, national or international basis. MPLS networks have the advantages of nearly unlimited bandwidth that can transport just about any voice, data or video protocol.

T1 Dedicated Internet Access (DIA) is the choice for broadband Internet access for many smaller businesses. The cost is only a fraction of what it was a decade ago. As a professional grade telecom service, you enjoy a reliability and constant bandwidth not typical of consumer oriented services like DSL and Cable.

The new competition to T1 lines is coming from Carrier Ethernet services, including Metro Ethernet. Like T1, Ethernet is a wireline service. Also like T1, it is delivered on multiple twisted pair copper wiring for lower bandwidth services. That copper wiring is generally already installed for multi-line telephone service. Ethernet offers the same point to point and Internet connections you may be using with T1 lines now. But Ethernet can also give you layer 2 switched network service between several or more locations around town or over a wider area, including overseas offices.

Ethernet is gradually taking over from T1 in metropolitan areas where it is most available. A popular service is 3 Mbps Ethernet for about the same price as a 1.5 Mbps T1 line. For more demanding uses, 10 Mbps Ethernet is becoming a popular standard.

Once you get into the higher bandwidths, 45 Mbps and above, fiber optic cabling takes the place of twisted pair copper. DS3 is the T-carrier upgrade to T1. It is now delivered over SONET fiber optic services at 45 Mbps. The Ethernet equivalent is 50 Mbps Ethernet service, although Fast Ethernet at 100 Mbps is an industry standard and the speed of many local networks. Like copper-based Ethernet services Ethernet over Fiber tends to offer much lower costs per Mbps than equivalent traditional SONET telecom services.

You should also know that both T1 and Ethernet services have an option to get both telephone and Internet over the same line. Integrated T1 is the legacy wireline service. SIP trunking is the IP service that gives you VoIP telephony and broadband Internet access.

Have you been wondering if you are paying too much for the wireline services you’ve just kept renewing over the years? Find out by getting up to date quotes for both Ethernet and T1 or SONET wireline services from dozens of competitive service providers. The range of services and their current costs may astound you.



Note: Photo of multipair cable courtesy of Wikimedia Commons

Bandwidth For Data Center Consolidation

Companies are always on the lookout for ways to save money, while still delivering the same value to their customers. Efficiency improvements are a sure winner. You may think you’ve wrung out all the efficiency you can from your data centers, but have you?

Most organizations don’t appear fully formed. They start out as small operations to test the market and the concept. Over years or decades, they outgrow facilities, add new products, acquire and merge with other companies, and so on. At any given point in this process, there is generally something to be gained by stepping back and considering how you would set things up if you had a clean sheet of paper.

One byproduct of company mergers and expansions is that you wind up with multiple data centers. Each installation made sense at the time. They are uniquely designed to serve the needs of a certain type of company, a certain size enterprise or certain product line. But when conditions change, you can find that there are creeping inefficiencies that come from patching things together here and there. It all works, but it may be costing you more than it could.

Data center consolidation is an activity that many companies are taking a closer look at, especially as top line growth stagnates and staff has been thinned out. You may not want to put everything in one location for the sake of redundant backup. But you may have bits and pieces here and there that can be easily combined. Fewer locations with fewer servers, larger servers and virtualization are all techniques that ultimately lead to the same or better performance at reduced cost.

Something to bring into the analysis is the cost and availability of bandwidth to support your consolidation efforts. That’s especially true if only the data centers are being consolidated but other operations continue at your geographically diverse locations. You’ll need some way to get data from place to place. That task used to fall to the site LAN, but now you’ll need a WAN connection.

Depending on how much traffic leaves data center and goes to each site, you may not need the same bandwidth that you have on your LAN. Workers at each location need access, of course, but the heavy processing may be local to the data center with just data entry and results going across the WAN. You’ll need to ascertain that bandwidth requirement and then check availability and pricing of bandwidth options.

Fortunately, bandwidth today is cheaper than ever with more options available. Ethernet is becoming more and more popular. It tends to be cheaper per Mbps than traditional T-carrier and SONET services. You can get point to point Ethernet line services or multipoint Ethernet LAN service. MPLS networks are often an excellent solution to the task of interconnecting multiple sites. They offer managed bandwidth, class of service options, and lower costs that proprietary networks.

Some companies are finding the the place to consolidate their data centers is in a colocation center or “carrier hotel” This is a completely managed facility will physical security, fire protection, backup power and a full time technical staff. You’ll often find the best bandwidth deals at colo centers because carriers establish points of presence within the facility to reach many customers at once. With multiple service providers vying for your business, you can often get outstanding deals on any level of bandwidth your require.

Are you in the midst of or considering a data center consolidation project? If so, get competitive quotes for your bandwidth needs from multiple service providers. This will help you minimize your costs, while getting the performance you need.

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.