Thursday, September 23, 2021

Gigabit Ethernet Replaces DS3 and T3

By: John Shepler

T3 lines and DS3 bandwidth have long been a staple of telecom service offerings. The rise of Carrier Ethernet WAN, point to point microwave for business and DOCSIS 3 cable broadband is causing these traditional telco services to fade into legacy services. Let’s have a look at what’s available for your business in the 50 to 1000 Mbps speed range.

Gigabit Ethernet replaces DS3 and T3 now.Telco’s T1 Line Upgrade
The pioneering work on digital transmission over long distances was done by Bell Labs right after WWII. Their first product was called T-Carrier and consisted of T1 and T3 services that were compatible. T1 lines could replace 24 analog phone lines with one multiplexed T1 line.

T1 was designed to run on the same twisted pair copper wires that supplied analog POTS landlines for easy deployment. T3 is an upgrade that ran on coaxial copper lines and microwave towers at 45 Mbps. It can handle 672 voice lines. The protocol that runs on T3, called DS3, can also be carried on SONET fiber optic circuits. When the Internet arrived, both T1 and DS3 were offered in clear channel versions to carry packetized data. T1 runs at 1.5 Mbps. DS3 or T3 runs at 45 Mbps.

Carrier Ethernet over Fiber Takes Over
Computer generated data far exceeds telephone traffic these days. The near ubiquitous standard is Ethernet on the LAN running the Internet Protocol or IP. With T1 or DS3, you need to do a protocol conversion at each end to go from the computer standard to the telephone standard and back again. The introduction of Carrier Ethernet keeps everything in one standard, Ethernet, from end to end.

Carrier Ethernet has been deployed in two versions. The slower version is Ethernet over Copper or EoC. This is a direct replacement for T1 lines and fractional DS3 service and runs from about 1 Mbps to 20 Mbps or so depending on the length of the circuit. The key feature is that it uses the same twisted pair wiring as T1 line or analog phone lines.

The faster version of Carrier Ethernet is Ethernet over Fiber or EoF. This is the technology that is rapidly taking over the world. EoF gives you end to end Ethernet from about 10 Mbps to 10 Gbps and even 100 Gbps in some areas. As you might expect, Ethernet over Fiber easily replaces T3 lines or DS3 bandwidth over SONET. It also offers the ability to easily upgrade to higher speeds than 45 Mbps any time you want. With a Gigabit Ethernet port, you can start off at 50 or 100 Mbps and scale up to 1,000 Mbps with just a phone call or click of a mouse online. There is no need to change out equipment. Only the speed of the line and your monthly billing will change.

The other big advantage of Carrier Ethernet, and some say the most important one, is the cost reduction compared to traditional telco services. You can get EoF service at DS3 bandwidth speeds of 50 Mbps for a fraction of what you would pay for actual DS3 over SONET. 100 Mbps, 1000 Mbps and 10,000 Mbps are suddenly affordable when you upgrade to Ethernet over Fiber.

Wireless is Fiber Without the Fiber
There are situations where fiber just doesn’t work despite all its advantages. One is is rural or remote areas that haven’t been wired, perhaps not even for telephone. The other is in dense urban areas where fiber has yet to be installed. The cost of construction is astronomical in both situations but that doesn’t mean you are out of luck. Just skip the fiber or wires completely.

Point to point microwave was a staple of telephone long haul. Microwave relay towers would retransmit the phone calls every 30 miles or so. Microwave is still applicable on a smaller scale over reasonable distances. In downtown business districts a dish on the roof pointed at the provider's antenna a few blocks away can give you Gigabit level bandwidth with very little construction cost. it’s also fast to install compared with pulling cables under the street.

In more rural areas, a WISP or Wireless internet Service Provider gives similar service usually at somewhat lower bandwidth levels, but similar to DS3 or better. Customers point their antennas at the service tower which can be miles away, but in a direct line of sight.

Another popular arrangement is to take advantage of the fact that every cell tower is also transmitting Internet traffic for smartphones. 4G LTE is commonly available and can give you the performance of fractional DS3 at least on download. Many smaller businesses can get all the performance they need from 4G without any of the wiring headaches. This is especially valuable for mobile or pop-up stores and individual entrepreneurs. Now that 5G is well into deployment, cellular can easily replace DS3 and higher speeds.

One thing to be aware of with wireless services, especially cellular, is that there are usage limits to most plans. That’s because the system can handle less traffic than fiber and the bandwidth must be shared fairly among users. Even so, if you can get 300 GB per month plans and pay much less than DS3 or even a T1 line, wireless can make a lot of sense.

Cable Broadband Can Mimic Fiber
The old Cable TV networks have been vastly upgraded and are now mostly run on fiber. It’s just that last link into your building that is run with coaxial cable. The protocols have also been upgraded along with the switch from analog to digital television. DOCSIS 3.0 and 3.1 offer high speed performance at bargain prices. You might be surprised to know that DOCSIS 3.0 can support bandwidth up to 1 Gbps download and 200 Mbps upload. The newer DOCSIS 3.1 standard is good to 10 Gbps download and 1 to 2 Gbps upload. When DOCSIS 4.0 is deployed, that upstream capacity will increase to 6 Gbps.

Cable broadband is extremely popular with residential users and many businesses. You just can’t beat the pricing. The only limitations are that cable isn’t available in many rural areas and the bandwidth is multiplexed or shared among many users. Thus speeds can vary. Like wireless, there is a large difference between download speeds and upload speeds. Uploading is typically a tenth or less the speed of downloads. That reflects the way Internet traffic usually flows. In many cases, this may make no difference to your operation, but it you need very high upload and download speeds and dedicated bandwidth, especially for cloud services, you may need fiber optic service through cable companies or other competitive fiber network providers.

Do you still have an old DS3 or T3 contract or simply need high performance, low cost bandwidth in the 50 Mbps or above range? If so, discover what Gigabit Ethernet services are available for your business.

Click to check pricing and features or get support from a Telarus product specialist.

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