History of Data
Communication
Data communications history represents a blend of histories,
including:
§ The history of the telecommunications industry
§
The history of data communications, and
§
The history of the Internet
™ Telegraph 1837 Samuel Morse Modern telecommunication industry began
in 1837 with the invention of the telegraph by Samuel Morse
This led to building a telecommunications infrastructure of
poles and wires as well as to the development of communication hardware and
protocols
™ Telephone 1876 Alexander Graham Bell Invention of telephone by
Alexander Graham Bell in 1876 and the development of wireless communication
technology by Guglielmo Marconi in the 1890s set the stage for today’s
communication industry
By 1950’s
By 1950s, telephone and telegraph companies had developed a
network of communication facilities throughout the industrialized world
1970’S Although
development of databases, languages, operating systems, and hardware was strong
from 1950s to 1970s, large-scale data communication systems did not emerge
until the 1970s.
This was
stimulated by 3 major developments:
§ Large-scale integration of circuits
reduced cost and size of terminals and communication equipment
§ New software systems that facilitated
the development of data communication networks
§ Competition among providers of
transmission facilities reduced the cost of data circuits
PROTOCOLS
As discussed earlier, “Protocol
is a set of rules governing communication”
o Two computers cannot just send bit streams to each other
and expect to be understood o Entities must agree on a PROTOCOL
9 Same Example French and German
Protocol defines:
What is Communicated?
How it is Communicated?
When it is Communicated?
File transfer
application
File Transfer contains all of the logic is unique to the
file transfer application such as:
o
Transmitting passwords
o
File Commands
o
Checking File System on other machine if it is
ready
o
Check File System Compatibility
o
File records
Communication service
module Instead of allowing File Transfer Module to deal with actual
transfer of data and commands, we can have a separate module for this transfer.
This module must make sure that the receiver system is ready to receive and
look into the reliable exchange of data
Network access module
Nature of the exchange between systems is independent of the
network that connects them. That allows us to have a 3rd module that handles
the details of the Network interface and interacts with the network. If Network
to be used changes, only Network access Module has to change
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