| Don't be confused about the difference between DS3 | | | | 56 bits total/frame |
| and T3 circuits. These terms are really synonymous. | | | | F-bits (framing) 28 bits/ |
| Instead you should focus on what they can do for | | | | M-bits (multiframing) 3 bits/ |
| you...and the best scenarios for application. | | | | C-bits (stuffing) 21 bits |
| Digital Signal (DS) is a system of classifying digital | | | | X-bits (message) 2 bits/ |
| circuits according to the rate and format of the signal | | | | P-bits (parity) 2 bits/ |
| (DS) and the equipment providing the signals (T). DS | | | | Data bits between overhead bits 84 |
| and T designations have come to be used | | | | A DS3 connection is comprised up of two monthly |
| synonymously so that DS1 implies T1, and DS3 implies | | | | charges: the local loop and the port charge. The local |
| T3. | | | | loop charge is the cost of the circuit provided by the |
| A DS3 line (also known as a T-3) is an ultra | | | | Local Exchange Carrier (LEC) that allows DS3 access |
| high-speed connection capable of transmitting data at | | | | into the carrier's network. The loop charge is based on |
| rates up to 45 Mbps. A DS3 line is equal to | | | | the distance from the customer's location to the edge |
| approximately 672 regular voice-grade telephone lines, | | | | of the carrier's network; the farther the customer is |
| which is fast enough to transmit full-motion, real-time | | | | from the network, the more the loop will cost. Nearly |
| video, and very large databases over a busy network. | | | | every carrier prices loops differently so it is in your |
| A DS3 line is typically installed as a major networking | | | | best interest to price DS3 service with several |
| artery for large corporations and universities with | | | | providers to ensure that you get the best deal. |
| high-volume network traffic. Other example | | | | DS Internet Access is the ideal solution for businesses |
| applications include large call centers, enterprise wide | | | | that require high-bandwidth access at a reduced price. |
| VoIP and IP PBX systems, Internet service providers, | | | | Whether you host high-traffic Web sites, support Web |
| research labs, video conference centers and software | | | | hosting or need high-capacity bandwidth on an |
| development companies. A DS3 is the second fastest, | | | | as-needed basis, there's a level of DS3 service (Full or |
| non optical connection offered in North America. A | | | | fractional) that will meet your needs. Fractional to full |
| DS3 line is comprised of 28 T1 lines, each operating at | | | | DS3 or T3 circuits run from speeds of 3 Mbps up to |
| total signaling rate of 1.544 Mbps. | | | | 45 Mbps. |
| DS3 circuits provide businesses and Internet Service | | | | For customers that require more bandwidth than a T1 |
| Providers (ISPs) with up to 45 Mb/s of dedicated | | | | line can provide but do not yet require the capacity of |
| Internet connectivity. This is an ideal solution for users | | | | a full DS3 line, a fractional DS3 connection is the ideal |
| who have outgrown their T1 connections and are in | | | | solution. A fractional DS3 is similar to a full DS(T)3, only |
| search of unlimited, high-capacity access. A DS3 line | | | | with some of the channels turned off. This reduces the |
| actually consists of 672 individual channels, each of | | | | total monthly cost and provides additional capacity that |
| which supports 64 Kb/s. DS3 lines are extremely high | | | | can be turned up in a matter of days. Unfortunately, |
| bandwidth connections into a carrier's backbone. They | | | | the DS3 (T) loop is still required for this service. |
| typically include SLAs (Service Level Agreements) that | | | | If a full DS3 line is more bandwidth that you really need, |
| guarantee uptime and performance. | | | | it is also possible to get Fractional DS3, which gives |
| The DS3 signal itself is composed of 28 DS1 signals | | | | you a portion of full DS3 bandwidth at a lower cost. Of |
| and is constructed using a two-step multiplexing | | | | course, DS3 is also available in multiples to increase |
| process. First, the 28 DS1 signals are multiplexed into | | | | bandwidth, similar to bonded T1 service. |
| seven DS2 signals. Second, the seven DS2 signals are | | | | DS3 service can be deployed for a wide verity of |
| multiplexed into one DS3 signal. Each multiplexing step | | | | applications. The most common uses are DS3 |
| uses bit stuffing to handle the different input | | | | point-to-point, DS3 internet, DS3 frame relay, DS3 |
| frequencies. Overhead bits provide alignment, error | | | | voice and DS3 VPN. The pricing for these connections |
| checking, in-band communications, and bit stuffing | | | | varies widely depending on the carrier, location of |
| control information. | | | | service and the application for which the connection is |
| Line rate: 44,736,000 b/s | | | | being used. Visit DS3 Bandwidth to obtain current "real |
| Signals: 7 DS2 signals = 28 DS1 signals | | | | time" rate quotes for your location. |
| Overhead bits: | | | | |