| If your business class DSL or T1 broadband | | | | highest OC level you can get at present is |
| service no longer has enough speed to meet your | | | | OC-768 which runs at 39,512 Mbps or about 40 |
| bandwidth needs for video or data transfer, you | | | | Gbps (Giga bits per second). |
| may be considering a move up to DS3 or T3 | | | | When does DS3 or T3 service make sense? If all |
| service. According to my compatriot John Shepler | | | | you require is 2 or 3 times the speed of a T1 line, |
| of ....here's when that makes sense and when it | | | | then you are better off with multiple T1 lines or |
| doesn't. | | | | connecting them together in what is called bonded |
| What's the difference between DS3 and T3? Ah, | | | | T1 service. Once you get past 6 or 8 T1 lines, the |
| what's in a name? Both of these terms have their | | | | price of a T3 line is often competitive. Remember, |
| origination in the T-carrier system, originally | | | | with T3 you get the equivalent of 28 T1 lines, |
| developed to provide high speed "trunk" lines | | | | which is a LOT more capability. |
| between telephone company offices. Everything is | | | | DS3 Bandwidth generally makes sense for |
| based on DS0 or "digital signal level zero" which is | | | | corporations that have a need for high speed |
| a 64K bit per second channel. Group 24 DS0 | | | | electronic data transfer between plant sites or |
| channels together and you have a DS1. When the | | | | offices. Very large call centers, enterprise wide |
| DS1 is connected to a wire circuit, it is called a T1. | | | | VoIP and IP PBX systems, Internet service |
| T1 runs at 1.544 Mbps (megabits per second). | | | | providers, universities, research labs, video |
| Not fast enough? OK, group 28 DS1 channels | | | | conference centers and software development |
| together (equivalent to 28 T1 lines) and you have | | | | companies are also good candidates for T3 lines |
| a DS3 or digital signal level 3 running at 44.736 | | | | with DS3 level service. |
| Mbps, or 45 Mbps for short. Connect that to a | | | | DS3 transport may be a cost effective substitute |
| wire circuit and its called a T3. By the way, that | | | | for point to point microwave for MPEG Broadcast |
| T3 line is equivalent to 672 voice channels. DS3 | | | | Video Transmission. It is also applicable for |
| and T3 terms are often used interchangeably. | | | | Surveillance Cameras, CCTV Systems, and VLAN |
| So, are T3 and OC-3 equivalent? No, not really. T3 | | | | Trunks. |
| is the "big daddy" of the T-carrier system. T3 is | | | | If a full DS3 line is more bandwidth than you really |
| copper wire based, although using coaxial cable | | | | need, it is also possible to get Fractional DS3, |
| rather than pairs of phone wires to support the | | | | which gives you a portion of full DS3 bandwidth at |
| higher speed. | | | | a lower cost. Of course, DS3 is also available in |
| OC-3 is another animal entirely. It is part of the | | | | multiples to increase bandwidth, similar to bonded |
| Optical Carrier (OC) levels defined for a fiber optic | | | | T1 service. |
| transmission system called SONET (Synchronous | | | | How much does DS3 (T3) cost? Glad you asked. |
| Optical Network). OC-3 runs at 155 Mbps verses | | | | You can get an instant online quote if you'll be so |
| T3 at 45 Mbps. That's a big difference in speed | | | | kind as to tell us where you want the service |
| and, as you might imagine, cost. | | | | located, and provide some basic contact |
| OC-1 service is the equivalent of DS3 or T3. It | | | | information so we can help you pick the optimum |
| provides 672 voice channels (or 64K data | | | | service for your business from available vendors |
| channels) and runs at 52 Mbps to include the | | | | in your area. |
| extra bits needed for the optical service. The | | | | |