Ethernet Better Than a T3 Line

By: John Shepler

Not long ago, T3 voice and data lines were a mainstay of medium and larger size businesses. Today, that once impressive 45 Mbps doesn’t seem all that fast. Our business applications demand more like 100 Mbps or 1,000 Mbps. Medical campuses, design firms and video production houses are more interested in 10 Gbps and looking beyond even that. If you still have a T3 line contract, you may well find that you can get more bandwidth for the same or less cost right now.

What is a T3 Line?
The T3 designation is part of the T-Carrier system developed by Bell Labs in the post-war tech boom. It was originally designed to transport large numbers of simultaneous telephone conversations and still fills that role for some larger businesses and call centers. Prior to T-Carrier, telecom was based on analog technology. T1 and T3 changed that to digital and started us down the path to the Internet we have today.

T3 is specified at 45 Mbps, enough to transport 672 digitized phone calls. That makes it a lot more efficient than creating a bundle of 672 separate twisted pair copper wires as telephone lines. T3 was once transported through large coaxial cables or microwave relay stations. More recently, it has been bundled on SONET fiber optic cables and called DS3. DS3 is the data format that runs on the physical T3 line, so DS3 and T3 pretty much mean the same thing.

The channelized version of T3 is used to carry those 672 phone calls, each in a separate channel or time slot in the data stream. For data transmission, the unchannelized version of T3 carries 45 Mbps worth of data, including the familiar packet switched networks.

Ethernet Replaces T3
Most all communications these days done over digital networks and originates in the most popular protocol, Ethernet. Even telephones have switched to an Ethernet interface so they can hook to the same network as computers instead of having separate wiring. This is called VoIP or Voice over Internet Protocol. With computers and phones on the same network, it makes sense to transport everything over Ethernet on both the local and wide area networks.

This is exactly what is happening. Carrier Ethernet, the long haul version, is replacing other telecom protocols such as T-Carrier for copper line and SONET for fiber optic. It’s pretty much going all Fiber optic Ethernet now. This is often referred to as Ethernet WAN for Wide Area Network.

Cost and Performance Advantages of Ethernet
The first advantage of long haul Ethernet transmission is that it is directly compatible with most all company networks. You simply plug the Carrier’s Ethernet into your router. There is no need for separate protocol conversion boxes or modules as required to support T1 and T3 lines.

A second advantage is that Ethernet is easily scalable. You can run at any speed up to the limit of the physical port from the Carrier. T-Carrier and SONET protocols were designed for specific speeds and needed to have hardware replaced to upgrade. The bandwidth of your line is set by the Carrier based on your contract. You can easily increase or decrease that as your needs change and it will be reflected in your billing.

Perhaps the biggest incentive to switch to Ethernet WAN service is pricing. You may be shocked at how much your can save by switching from an older telecom service to Ethernet WAN. Ethernet is almost always lower in cost on a per-Mbps basis. Sometimes the difference can be a factor of two or more.

Much of the cost savings comes from a more competitive environment for fiber optic Ethernet versus the old telco services with one provider. There may be several companies offering Ethernet bandwidth for your business at competitive rates.

Fiber is also more available than ever before. The upgrade of cellphone towers to 4G LTE and 5G has demanded a rapid expansion of fiber optic networks. Copper is yesterday’s news and, more and more, it is being left to rust in the ground. Fiber and wireless are the future for networking.

Do you have legacy T3 or DS3 service and want to see if you can get a better deal? That’s easy. Just check prices and availability of Ethernet WAN service for your business address. Chances are good that you can get more bandwidth for the same or less cost than what you pay now.

T1, T3 and Ethernet Bandwidth

By: John Shepler

Are you considering new or additional bandwidth for your business office, retail store, or other commercial location? Professional grade options include high performance T1 lines, T3 (DS3) lines, and Ethernet options over copper and fiber optic cables.

T1 Lines
T1 Lines have been the mainstay of many, many businesses for decades. They still are, although for more special situations. The big advantage of T1 lines is that they are provisioned over standard twisted pair copper telephone wiring. If you can get landline phone service installed, it’s likely you can also get T1 service. That includes rural areas where there isn’t much else to pick from.

T1 lines are highly reliable, get fast service if something goes wrong, and are dedicated to your use only. The bandwidth is symmetrical. That is, the upload and download speeds are identical. That’s important if you exchange large data files or back them up to the cloud.

T1 lines can be configured for dedicated Internet access or point to point connections. They support ISDN PRI telephone trunks for multi-line phone and PBX systems. Their one limitation is the bandwidth, which is fixed at 1.5 Mbps. That’s rather slow in broadband terms, but perfectly useful for small business point of sale terminals, email and casual web browsing. Additional T1 lines can be bonded to increase the bandwidth to 3, 4.5, 6 or even 10 Mbps.

Ethernet over Copper Lines
Ethernet over Copper (EoC) is a modern technical upgrade to legacy T1. It uses the same copper telephone lines, but can support higher speeds. Bandwidths of 10 or 20 Mbps are common within metro areas. Some support is also available for rural businesses, but not as ubiquitous as T1 service. Additionally, EoC is generally less expensive per Mbps than traditional T1 lines. You can often get twice or more bandwidth for the same monthly lease cost.

T3 Lines
T3 lines are in the same technology family as T1 lines. The bandwidth is much higher, 45 Mbps vs 1.5 Mbps. T3 refers to the actual lines, which are coaxial, waveguide or microwave relay. These days T3 is delivered as a service on SONET fiber optic lines and referred to as DS3. Like T1, T3 or DS3 service is highly reliable, dedicated and symmetrical.

Ethernet over Fiber Lines
Ethernet over Fiber (EoF) is the modern technical upgrade to SONET fiber optic service. As such, EoF replaces T3 and DS3 with the same bandwidth at a better price. Unlike T3 and DS3, Ethernet over Fiber offers a wide range of bandwidth choices instead of the fixed 45 Mbps service. You can typically get EoF service from 10 Mbps on the low end up to 10 Gbps or even 100 Gbps. You also have the option of changing your mind at any time to upgrade or downgrade your service. Usually, no hardware changes are required. You are billed for the bandwidth level you order rather than a fixed 45 Mbps.

Until recently, fiber optic service was limited to major metropolitan areas and rather expensive. The entrance of competitive service providers and the high demand to supply cell towers to support 4G and 5G broadband has vastly increased the amount of fiber optic services available. Most offices, business parks and retail locations now have the option for competitive fiber bandwidth pricing. Some lines are even available to rural locations.

You have a wide range of possibilities for your business bandwidth that include T1, T3 (DS3) and Ethernet over Copper and Fiber. Check pricing and availability now.

DS3 and Fractional DS3 Broadband

In the quest to upgrade bandwidth, companies have generally turned to DS3 bandwidth service. Here is what DS3 is all about and the different technologies used to provide DS3 and similar mid-level bandwidth services.

DS3 stands for Digital Signal 3, a standardized switched circuit TDM telecom service. As a refresher, DS0 is the basic building block at 64 Kbps. That’s one channel of digitized telephone call. DS1 is a bundle of 24 DS0 channels at 1.5 Mbps. You are probably more familiar with its implementation as a line service called T1. DS3 is the next step up at 45 Mbps. It’s a bundle of 672 DS0 channels as a large telephone trunk or 28 T1 lines multiplexed together for transport. When you order a T3 line, you are getting the line service implementation of DS3.

Even though DS1 and DS3 were originally conceived as telephone company technologies, they are more often used to transport data packets today. That includes private point to point lines and dedicated Internet connections. In these applications, the entire payload is used to transport data packets.

A full DS3 circuit will give you 45 Mbps bandwidth in both the upload and download directions. This is the most common service ordered and is readily available nationwide. You’ll need an interface card for your router to connect to a DS3 termination. There are two interconnect cables, one for transmit (upload) and one for receive (download). They are 75 ohm coax, similar to what you’ll find for Cable TV connections, although the specified cable type is Bellcore 734 or 735 for this application. The connectors are type BNC. You’ll find these on the router interface card. There may be more than one pair if the router can handle multiple DS3 connections.

At this point, you might be imagining coaxial cables stretched from your building back to the telephone central office, like the twisted pairs used for T1 and multi-line telephone service. In practice, the coaxial connection is only used for short distances. The DS3 bandwidth itself is most often delivered over a SONET fiber optic cable, where it is demultiplexed and dropped off at your premises.

DS3 bandwidth may be higher than you require. There’s a big gap between T1 line bandwidth at 1.5 Mbps and DS3 at 45 Mbps. Companies often begin scaling up their bandwidth by bonding multiple T1 lines to double or triple the individual line bandwidth. This works up to about 10 or 12 Mbps in most cases. Let’s say you only need 20 or 30 Mbps right now. What do you do?

One option is to order fractional DS3 service. A full DS3 interface is installed, but the line bandwidth is limited to the fractional amount you order. That could be 15, 20 or 30 Mbps. You can possibly save money this way, but not necessarily. The reason is that full DS3 is more of a standard service that is readily available. The fractional services are a special order that may or may not be available in a particular location, depending on the service provider. In the end, it might make the most economic sense to get a full DS3 connection.

There are other technical options in this bandwidth range that compete with fractional and even full DS3. The most popular is Ethernet over Copper. This is a highly scalable service that competes with T1 at the 1.5, 2, and 3 Mbps levels. You can also get 10, 15, 20, 25, 30, 50, and sometimes even 100 Mbps Ethernet over Copper. This lets you match your budget more closely to the bandwidth you require. Ethernet over Copper (EoC) is often less expensive than either T1 or DS3 for similar bandwidths, although not as readily available as yet.

Downtown in major business districts you may also find fixed wireless bandwidth services. These often deliver DS3 bandwidths, but perhaps in an Ethernet protocol. Most of the time that’s what you want anyway, since you’ll be connecting to a LAN running Ethernet.

A final option isn’t DS3, but might give you a similar benefit for a lot less money. That’s business class Cable broadband. It is shared, not dedicated, and the bandwidth varies with the amount of user activity. Still, you can get up to 50 or 100 Mbps download with 5 or 10 Mbps upload service for about the price of a T1 line. You’ll need to have the cable passing by your business location for this service to be available. Otherwise the construction costs are prohibitive.

Are you in need of higher bandwidth to support your growing business, additional computerization or a move to cloud services? If so, get pricing and availability for DS3 and fractional DS3 services, plus related bandwidth services that may also meet your needs.

Gigabit Ethernet Port Scales WAN Bandwidth

When you are ready to make the move from copper to fiber bandwidth levels or upgrading an OC-3 SONET service, you are faced with a choice. What level of bandwidth do you install?

Why not give yourself flexibility for the future and the opportunity to pay only for what you need right now? This is what a Ethernet port strategy can do for you.

Scalability is a new idea in business telecom services. When you install a T1 line, it requires a very specific T1 interface that include a CSU/DSU circuit unique to the T1 line specifications. Upgrade to a T3 line (DS3 bandwidth) and you’ll find that you can’t just plug that T3 into your T1 router. The interface is completely different. Even the connecting cable is different. With DS3 you are looking at a pair of coaxial BNC connectors that don’t support any other service. Now, make yet another move on up to OC-3 service. Your router interfaces for T1 and T3 are no good. You need a fiber input to your router.

It doesn’t get any better when you start moving up the fiber optic hierarchy. You can’t just plug OC-12 or OC-48 into an OC-3 port and have everything spring to life. They are different services requiring modifications. You’ll likely need a new interface card and programming changes to your router. If you have a managed router, that probably means a truck roll to your premises to swap out the CPE (Customer Premises Equipment).

In the back of your mind, you must suspect it doesn’t have to be this way. Those new PCs have NICs (Network Interface Cards) labeled 10/100/1000 Mbps. That means that you can plug them into any LAN running at up to 1 Gbps and they’ll work just find. Even the connector takes the same RJ-45 patch cord. Wouldn’t that approach be far superior for WAN connections too?

This is the beauty of Carrier Ethernet, which includes Metro Ethernet, MPLS network access and long haul point to point connections. Ethernet beyond the LAN has been designed to be as flexible as Ethernet on the LAN.

One of Ethernet’s best features as a bandwidth service is ease of scaling. If you are running 50 Mbps service and find your needs have increased so that you now need 100 Mbps, you can just call up your service provider and request an upgrade. In a matter of hours or a day or two at the most, your WAN network speed will double. In that time, no one has knocked on the door with a new router under their arm. In fact, you haven’t seen anyone from the service provider. It was all done over the phone.

There is a trick to making this work. The magic is all in the installed Ethernet port. When you order Ethernet service, make sure that you have a port installed that will support the highest bandwidth you reasonably expect to be ordering down the road. Most ports are the standard Ethernet speeds of 10 Mbps, 100 Mbps and 1,000 Mbps. It’s also possible to get a 10,000 Mbps or 10 GigE port with a suitably fast managed router if your needs are that high.

With Ethernet over Copper, you are probably looking at a 100 Mbps Ethernet port at most. Be sure you know just what your maximum speed will be, because EoC is distance limited and requires more copper pairs as speed increases. Ask what bandwidth your installation will support compared to what you are ordering initially.

With Ethernet over Fiber, it likely makes sense to install a Gigabit Ethernet port. The fiber itself has more capacity that you are ever likely to employ. The speed of the port will be the limiting factor, along with the capability of the carrier’s equipment that feeds that port. Once again, it is smart to plan for the future but buy for today. Get the bandwidth you need now, but be sure that the system is engineered to allow for fast and easy upgrades as you need them. That will be especially handy if you get hit with a sudden increase in traffic or a need to support massive amounts of video or enormous file transfers that you didn’t anticipate.

Are you ready for a bandwidth upgrade, but unsure of what commitment to make? Give yourself some breathing room with a Gigabit Ethernet port and the ability to scale up your bandwidth as needed. Get prices and availability of Ethernet ports and line speeds now.

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.

D3 vs DS3 Bandwidth Choices

Medium and larger size companies have long chosen DS3 services to obtain the bandwidth they need for broadband Internet access. Now there’s a new player in the marketplace that is looking to complement if not displace the venerable DS3 connection.

If you need business bandwidth higher than you can get by bonding T1 lines, you already know about DS3. But how much do you know about D3?

D3 is short for DOCSIS 3.0, a cable broadband standard that gives HFC (Hybrid Fiber Cable) systems a capability that rivals fiber to the premises. It is now possible to get 50 Mbps for business use from cable systems in many cities. Some have 100 Mbps available and more will have that service offering soon. DOCSIS 3.0 can provide 152 Mbps, with even higher speeds possible. Compare that with DS3 at 45 Mbps and you can see why there is a natural competition between the services.

The raw bandwidth specs don’t tell the whole story, however. D3 and DS3 are different technologies with different characteristics. You may find that one or both of these services make sense for your business.

DS3 stands for Digital Signal, level 3. It was developed as part of the T-Carrier specification by Bell Labs for use by the telephone companies to transport up to 672 simultaneous telephone calls between phone company switching centers. When provisioned over coaxial copper lines, it is called T3 line service. If you suspect that T3 is related to T1, you are right. A T3 line can transport the equivalent of 28 T1 lines on its higher bandwidth.

DOCSIS 3.0 has a Cable TV rather than a telephone company heritage. The DOCSIS standard was developed by CableLabs (Cable Television Laboratories, Inc.) with contributions from other companies serving the cable industry. If you have Cable broadband, you are using a DOCSIS modem. It’s only a question of which version you are using. The original was DOCSIS 1.0, which has been supplanted by DOCSIS 1.1, DOCSIS 2.0 and now DOCSIS 3.0.

DS3 is based on multiplexing 672 channels of 64 Kbps each to create total bandwidth of 43 Mbps. Add the necessary synchronization and control bits and you have a bandwidth of 44.736 Mbps. Why so many channels? Each of those 64K channels is just the right size to carry one telephone call. That’s the telco heritage of DS3. Combine all the channels into one large pipe and you have nearly 45 Mbps of digital bandwidth.

D3 is also based on channels. In this case, each channel is 6 MHz wide. That’s the width of one television channel. Everything on a cable system is treated as a TV channel, so broadband services have to fit into those channels to get through the amplifiers and wiring on the system without interfering with any other channels. A 6 MHz channel can transport a 38 Mbps broadband signal in one direction. Cable operators bond channels together to get higher bandwidths. With 4 bonded channels, DOCSIS 3.0 can deliver a download speed of 152 Mbps.

So, are D3 and DS3 the same beyond their different technology heritages? Not really. The telco heritage of DS3 means that it is a dedicated symmetrical bandwidth service. You get 45 Mbps in both the upload and download directions. That bandwidth never varies. It is called dedicated because it is completely dedicated to your needs. Anytime you don’t use the full 45 Mbps, it just sits there and idles while waiting for more data.

D3 is an asymmetrical shared bandwidth service. You get different speeds in the upload and download directions. Download is faster to reflect the fact that most users download more content from the Internet than they upload. Typical business bandwidth services are 50 Mbps download and 10 Mbps upload or 100 Mbps download with 10 Mbps upload. This bandwidth is shared among many users on the system. Thus, you may experience your access speed varying all over the place depending on what other users are doing. If a lot of them are downloading movies or big software updates, everyone’s speed will be slowed.

DS3 service is generally sold with an SLA or Service Level Agreement that describes the expected performance and availability of the service, plus remedies if the provider doesn’t deliver as promised. D3 is a “best effort” service with no specific performance guarantees. Even so, it is in the provider’s best interest to provide adequate resources and service availability to keep the customers happy.

The difference in services are most dramatic when you look at the pricing. You might pay several thousand dollars a month for DS3 service with an SLA. D3 will probably cost you a tenth of that, with no guarantees. Which will work for your needs depends on if the cable system passes your business and if you can live with the variations in performance and lack of guarantees. Some companies have DS3 or even T1 lines installed for their mission critical or performance sensitive applications and D3 for general Internet access and low cost backup to their telecom services.

Are DS3, D3 or both bandwidth services right for your company? Why not talk to an expert consultant that can provide you with prices and availability of DS3, D3, and other broadband options for your business needs? There is no charge for this helpful service and you may be able to realize a considerable cost savings while achieving the same or better network performance as you have now.