Wednesday, January 21, 2009

DS3 Speed Challenged By EoC

Once a company has outgrown its T1 lines, the standard upgrade has been to move to DS3 for more bandwidth. But DS3 is typically delivered over fiber optic SONET connections. That can mean significant construction costs unless your building is already lit for fiber optic services. But now a new service offers DS3 speeds over standard copper telco wiring. Can this be a money saver? You bet it can.

The new service is called EoC or Ethernet over Copper. What it gives you is higher bandwidth services, even up to the DS3 level of 45 Mbps, without fiber optic cabling. But if DS3 requires fiber optics, why doesn't EoC?

The explanation is in the technology. DS3 is a signal level definition developed for the original T-Carrier digital telephone standard. It was originally deployed over coaxial copper cable called T3 lines. But coaxial copper has given way to fiber optic cable with its much higher bandwidth capability. Nowadays DS3 is most often deployed over SONET fiber optic services. The usual SONET service starts at OC3 or 155 Mbps. But the way the T-Carrier and SONET signal levels were defined, DS3 and even DS1 (the signal level for T1) are easily multiplexed and demultiplexed onto SONET carriers.

Ethernet over Copper, EoC, is something else entirely. It's not based on any of the earlier telco standards. But it uses telco wiring. The way that works is that the Ethernet provider leases the wires running to your building from the local phone company. Only the wires are leased. There's no dial tone or other services provided by the telco. Bare lines like this are called "dry pairs." The Ethernet provider hooks specialized termination equipment at each end of the dry pairs to transport the Ethernet signals. Usually a number of pairs are connected or "bonded" so that the system has enough capacity to deliver significant bandwidth.

The mechanics of how this is done are technically interesting, but are not something that you as a user need to deal with. The service provider will install customer premises equipment at your location to provide the interface between the copper telco pairs and the RJ45 connector that provides the WAN network signal to your local area network.

Nearly all businesses are already wired with multipair telephone cables used for traditional office telephone service. Some of the wires in these cables will be pressed into service to deliver your Ethernet service. But you should know that EoC is a limited range service. In other words, you need to be located within a few miles of a carrier office or POP (Point of Presence) to take advantage of this service. The closer you are to the POP, the higher the bandwidth you can get. Bandwidths of 5, 10, 20 and up to 45 Mbps are available depending on location.

Speed is one of Carrier Ethernet's advantages. The other is cost. Ethernet services tend to not just rival DS3 pricing, but can be considerably less costly as well. You can attribute that to aggressive new competitive providers as well as the technology. You may well find yourself paying less for EoC service for point to point data connections or dedicated Internet service that you would going with traditional DS3 over SONET. That's especially true if you don't need the full 45 Mbps but require more than the 1.5 Mbps you get from T1 lines.

Will Ethernet over Copper work for your business? Find out now what Ethernet services are available for your location.

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

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