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0101
Communications |
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70
Duck Pond Road
Stone Ridge, NY 12484 |
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Telephone:
800-219-7048
Contact for a no-cost data-quote |
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Broadband /
Data Communications definitions
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Bandwidth Speeds by
Connection Type |
| Connection Type |
Port Speed |
| DS-1 (T-1) |
1.544 Mbps |
| DS-3 (T-3) |
45 Mbps |
| OC-3 |
155 Mbps |
| OC-12 |
622 Mbps |
| OC-48 |
2488 Mbps |
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Definitions |
| Asynchronous
Transfer Mode (ATM) |
ATM is am international integrated
services digital network (ISDN) high-speed, high-volume,
packet-switching transmission protocol standard. ATM uses short,
uniform, 53-byte cells to divide data into efficient, manageable
packets for ultra fast switching through a high-performance
communications network. The 53-byte cells contain 5-byte
destination address headers and 48 data bytes. ATM is the first
packet-switched technology designed from the ground up to support
integrated voice, video, and data communications applications. It
is well-suited to high-speed wide area network (WAN) transmission
bursts. |
| DS-1,T-1 |
T1 is the equivalent of 24 multiplexed
voice grade channels (DS-0s), with a bandwidth of 1.5 Mbps. DS-1
circuits are used to carry moderate volumes of traffic by both end
users and carriers. |
| DS-3,T-3 |
T3's are the equivalent of 28 multiplexed T1
channels, with a bandwidth of 45 Mbps. DS-3 circuits are often
used to carry high volumes of long-distance traffic or to provide
resold DS-1 or voice-grade private line service. DS-3s are also
used by large companies for internal communications and for
dedicated internet access. |
| Fractional T-1 |
A fractional T1 digital service is a
hierarchy level 1 with service in multiples of 56 or 64 Kbps over
two channels at 112 or 128 Kbps or above, and up to 23 channels.
Common rates for this type of service are 256, 512, 768, and 1024
Kbps. FT-1 uses a portion of a 24-channel T1 circuit. FT1 allows
64 Kbps increments from 2-channel 128 Kbps through all 24 channels
at 1.544 Mbps. |
| Fractional DS-3 |
DS3 is a fractional digital service
hierarchy level 3 with service in multiples of 1.344 Mbps. FT-3
uses a portion of a 672-channel T3 circuit for any mix of voice,
data or broadcast-quality video. |
| Frame Relay |
A frame relay is wideband (64 Kbps to 1.544 Mbps)
high-speed packet-based data switching interface standard that
transmits bursts of data over wide area networks (WANs).
Frame-relay packets vary in length from 7 to 1024 bytes. FR is
based on link access procedure of D-channels (LAPD) protocol.
Since frame relays are data oriented, they are not usually used
for voice or video. It has error detection, but has no error
correction. |
| T-1,DS-1 |
24 voice channels, each digitized
at 64,000 bps, combined into a single 1. 5 Mbps digital stream
(8,000 bps signaling), and carried over two pairs of regular
copper telephone wires. T1 was used primarily by telephone
companies until 1983. Now it is used for dedicated local access to
long-distance facilities, long-haul private lines, and for regular
local telephone service. Today, most 1.5 Mbps digital streams are
called T1, regardless of their makeup or transmission medium. T1
is available in many versions, including: formatted Accunet, a
formatted T1 offering that requires compliance with both AT&T
DSX-1 hardware and DS1 software standards; and unformatted, which
only requires compliance with the DSX-1 standard. The formatted
version provides less usable bandwidth. |
| T-3, DS-3 |
A transmission link capable or
carrying 44.736Mbps (45 megabits) or 672 voice conversations, more
than enough for full-screen, full-motion video. A T3 is the
equivalent of 28 multiplexed T1 channels. |
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