Companies that grew up with T1 lines naturally graduated to T3 lines or DS3 connections as their bandwidth needs increased. These technologies are firmly established to deliver secure reliable bandwidth with low latency, packet loss and jitter. While you may be perfectly happy with the line service you have now, you might also be missing out on some advantages of new technology approaches.
T-Carrier Legacy
The story begins with the development of T1 lines starting after WWII. The impetus to create a new telephone trunking system was driven by the high cost and noisy performance of analog carrier telephony for long distance lines. T1 was the first digital replacement. It offered 24 digitized telephone lines on two pair of ordinary twisted pair telco cable. Each independent channel was time division multiplexed into a data stream running at 1.5 Mbps.
That’s still the spec for T1 lines. You can find the same channelized lines in use today for ISDN PRI telephone trunks to PBX phone systems. It’s organized as 23 phone lines and 1 control channel. Most T1 lines, though, have the channels combined to transport a 1.5 Mbps bit stream for data transmission. T1 lines can be combined or bonded to create larger “pipes”, up to about 10 or 12 Mbps.
T3 & DS3 Upgrade
T3 and DS3 use multiplexing compatible with T1 lines to create 28x the bandwidth or about 45 Mbps. T3 lines require frequencies too high to travel very far on twisted pair copper. T3 was originally provisioned on coaxial cable or via microwave towers. Later, fiber optic lines were implemented for long haul, with small diameter coax to the customer handoff in the building.
You might be wondering what the difference is between T3 and DS3. T3 is the physical circuit, coaxial cable or microwave link. DS3 is the signal that rides on the T3 line. The situation is similar for T1 lines. In that case, the signal is called DS1.
SONET Fiber Optic
Even the 45 Mbps bandwidth of a T3 line soon became a limiting factor for long distance telephony and the rise of digital computing. The next telco standard was a fiber optic definition called SONET for Synchronous Optical NETwork. SONET was designed to be compatible with DS1 and DS3 so that it was easy to multiplex or combine multiple DS3s onto, say, an OC3 at 156 Mbps. OC12 offers even higher bandwidth and OC48 was the prevailing network core bandwidth until recently.
Carrier Ethernet is a Game Changer
T-Carrier (T1 and T3) and SONET were products of the telephone companies and more suited to channelized telephony than computer data. Through a protocol conversion process they can be made to carry the standard Ethernet signals that run on LAN networks, but why not just keep everything in the Ethernet format end to end?
Why not, indeed! This is what Carrier Ethernet does. It replaces the earlier telco standards with long distance Ethernet directly compatible with in-house network connections. Instead of T1, T3, OC3, OC12 and OC48, you have Ethernet, Fast Ethernet, Gigabit Ethernet, 10 GigE and so on. A major difference is that Ethernet is easily scalable, while T-Carrier and SONET require equipment changes whenever you move to a higher standard.
Modernizing to Ethernet Connections
Carrier Ethernet networks, sometimes called IP networks because the protocol is the same as what is used on the Internet, are expanding rapidly to replace older Metro and Wide Area Networks. They offer the same dedicated, symmetrical bandwidth low in latency, packet loss and jitter. You can order point to point connections or dedicated connections to the Internet.
Ethernet comes in both copper and fiber options. Ethernet over Copper is a good upgrade for T1 from 3 Mbps up to 15Mbps, 20 Mbps or even more. Entry level Ethernet over Fiber is around 10 Mbps. Fiber is easily scaled to 50 Mbps that can replace T3 or DS3. It can also ramp up to 100 Mbps Fast Ethernet, 1000 Mbps Gigabit Ethernet and 10,000 10 Gigabit Ethernet. Even 100 Gbps Ethernet is available in some areas.
An Even Lower Cost Alternative
Business Cable Broadband is another service that has become extremely popular with small and medium size businesses. DOCSIS 3.0 and 3.1 modems offer an Ethernet connection to your network with speeds that easily reach 100 Mbps or 1 Gbps. An upgrade to 10 Gbps symmetrical bandwidth is being readied.
The attraction of cable is that it is readily available in most cities and often can be installed quickly with little or no construction charges. It is also the least cost per Mbps for the bandwidth you need. It is designed to work best for Internet browsing including video and file downloads. The bandwidth is generally asymmetrical, often as much as 10x as high in the download as upload direction. Cable bandwidth is shared, not dedicated, so you may find the speed varying throughout the day. Even so, many business and well and residential users are sold on cable broadband. For secure point to point connections you can use a VPN (Virtual Private Network) over the Internet.
Are you still on an old T3 or DS3 service contract? You’ll be amazed how much bandwidth you can get today for the same cost. Find out right now how many bandwidth providers serve your business location and what they offer.
