MCSE : Security Specialist
ATM
To
transmit data Asynchronous Transfer Mode uses fixed sized packets of
53 bytes long called cells and provides data transfer rates from 25
Mbps to 2400 Mbps. ATM can be used with twisted pair and fiber optic
cabling.
By
using standard sized cells, ATM can provide constant, high-speed
data streams that audio, video, and imaging applications require.
Frame Relay
Frame
Relay is a WAN technology, connection speeds range from 56 Kbps to
1.544 Mbps using a T1 carrier service, and speeds up to 45 Mbps
using a T3 carrier service. Frame relay is a packet switched
networking protocol.
To
connect two or more LANs using Frame Relay, a company must lease one
dedicated access line to the Frame Relay network for each LAN. Frame
Relay access lines often use a T1/ E1 line.
Sonet/SDH
Synchronous Optical Network, is a standard for optical
telecommunications transport. It was formulated by the ECSA for
ANSI, which sets industry standards in the United States for
telecommunications and other industries. The comprehensive
SONET/synchronous digital hierarchy (SDH) standard is expected to
provide the transport infrastructure for worldwide
telecommunications for at least the next two or three decades.
T1/E1
A
1.544 Mbps point to point dedicated, digital circuit provided by the
telephone companies. T1 lines are widely used for private networks
as well as interconnections between an organizations LAN and the
telco.
A T1
line uses two pairs of wire one to transmit, and one to receive. and
time division multiplexing (TDM) to interleave 24 64-Kbps voice or
data channels. The standard T1 frame is 193 bits long, which holds
24 8-bit voice samples and one synchronization bit with 8,000 frames
transmitted per second. T1 is not restricted to digital voice or to
64 Kbps data streams. Channels may be combined and the total 1.544
Mbps capacity can be broken up as required.
T3/E3
A T3
line is a super high-speed connection capable of transmitting data
at a rate of 45 Mbps. A T3 line represents a bandwidth equal to
about 672 regular voice-grade telephone lines, which is wide enough
to transmit real time video, and very large databases over a busy
network. A T3 line is typically installed as a major networking
artery for large corporations, universities with high-volume network
traffic and for the backbones of the major Internet service
providers.
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