If you’ve been using T1 lines for years, maybe decades, you know how solid and reliable they are. Your natural inclination is to stick with what’s working. After all, why mess with success? You should know that there are really good reasons to do just that.
What’s So Great About T1 Lines?The appeal of T1 lies in its design and technical maturity. T-Carrier technology, which includes T1, E1 and T3 (DS3) line services, was developed in the mid-twentieth century for long distance telephone trunking to replace noisy analog carriers. Being digital, it was easy to expand the role of T1 lines to carrying packets as well as PCM audio telephone calls.
T1 Service Characteristics
T1 lines come into your building on one or two twisted copper pair using the same wires that carry multi-line telephone. This means that you can get T1 just about anywhere you can get regular POTS phone service. The service is symmetrical, meaning that upload and download speed are the same. There are no usage limits. Whatever you can load on the line during the month, you can transport. This is a dedicated private line, meaning you are the only user and security is high. So, with all that going for T1, why would you want to make a change?
Time Marches On
The 1.5 Mbps bandwidth of T1 was more than enough for business users… once upon a time. Today, 1.5 Mbps is still enough for credit card verification, email, casual Web browsing, and backup for small computer systems. It’s not a bad choice for small retail operations and offices, especially in rural ares where other bandwidth services are hard to come by.
Most users are used to higher bandwidths now, even on their smartphones. They expect faster response and really need it to efficiently do their jobs. That’s OK. You can get higher bandwidth from T1 lines. It’s done by bonding two or more together to make one large pipe. The size of that bandwidth pipe ranges from 3 Mbps on up to about 10 or 12 Mbps. If you need more than that, you’ll have to look elsewhere.
How About T3/DS3?
A faster version of T1 is T3, also known as DS3. The terms T3 and DS3 generally mean the same thing, although, strictly speaking, T3 refers to the physical line and DS3 is the organization of the data.
T3/DS3 isn’t just a little faster than T1, it’s a lot faster at 45 Mbps. This is more than enough for most small operations and many medium size companies. That makes T3/DS3 the logical upgrade from T1, right?
Yes and no. T3/DS3 is, indeed, a popular line service. It’s available in many business locations, but not nearly as many as T1. That’s because T3 doesn’t use twisted copper pair wiring. It’s provisioned on a pair of coaxial cables. That’s only for the last few hundred feet at most. T3/DS3 is transported primarily by fiber optics. If the fiber passes near your location, you may be able to get T3/DS3. If not, you’ll need to stick with copper.
The Ethernet over Copper Option
A newer technology than T1 is called EoC or Ethernet over Copper. This never was a a telephone company product. It’s an extension of the LAN Ethernet protocol for metro connections. Whatever goes on your LAN can be carried by EoC.
The big advantage of Ethernet over Copper is that it uses the same twisted copper pair as T1 lines. A more advanced modulation scheme allows EoC to offer speeds ranging from 3 Mbps on up to 50 Mbps, sometimes higher. The tradeoff is that the farther you are from the provider office, the less bandwidth is available. EoC is quite popular in the 10 and 20 Mbps bandwidths.
Moving Up to Fiber
Carrier Ethernet is available over fiber as well as copper. This is called EoF or Ethernet over Fiber. Once you move up to fiber, the bandwidth limitations disappear. Fiber optic service typically starts at 10 Mbps, with 100 Mbps and 1 Gbps as popular service levels. Some companies and now requiring 10 Gbps EoC, which is more and more available.
You may already know that fiber optic service comes in two protocols: SONET and Ethernet over Fiber. SONET is an older service that is the fiber optic extension of T-Carrier. DS/T3 is generally transported to the curb over a SONET service.
Choosing Ethernet vs SONET
SONET fiber services typically range from OC3 at 155 Mbps on up to OC-192 at 10 Gbps, although higher bandwidths are available. The increments are 155 Mbps, 622 Mbps, 1.2 Gbps, 2.4 Gbps and 10 Gbps.
Carrier Ethernet works differently. There aren’t large increments in bandwidth. You can pretty much specify the bandwidth you want in the 10 Mbps to 10 Gbps range. Popular service levels are 10 Mbps, 100 Mbps and 1 Gbps. You’ll recognize these as standard Ethernet LAN speeds.
Ethernet over Fiber is not only much more scalable than SONET, it is generally less expensive. The cost difference can be dramatic in some locations. You may pay half or less for EoF as you would for SONET. You’ll still get highly reliable professional grade service with low latency, jitter and packet loss.
Are you feeling stymied by the limitations of your old T1 lines? Now may be the perfect time to migrate your connectivity to Ethernet over Fiber at a lower cost than you might expect. You’ll also be laying the groundwork for future expansion, with higher bandwidth levels quickly available as you need them.
