Master Course
Advanced Computer Networks
Lecture 1
Introduction and Review
Dr. Mahmoud Shuker Mahmoud
Chapter
Outline
1.1 A Brief History
1.2 Protocols and Standards
1.3 Standards Organizations
1.4 Internet Standards
1.5 Internet Administration
1-1 A BRIEF HISTORY
A network is a group of connected, communicating
devices such as computers and printers. An internet is
two or more networks that can communicate with each
other. The most notable internet is called the internet,
composed of hundreds of thousands of interconnected
networks. Private individuals as well as various
organizations such as government agencies, schools,
research facilities, corporations, and libraries in more
than 100 countries use the Internet.
1-1 A BRIEF HISTORY
Time-line for Networks and Internet Evolution
• 1967 – Small network by ARPANET proposed (Advanced Research and project
Agency at the department of Defense DoD)
• 1969 – ARPANET is a reality between four Universities at Calefornia.
• 1972 – Interneting project (by Vin Cerf, Bob kahn) linking different networks
together and proposing to use a gateway to overcome the some problems.
• 1973 – TCP protocol for end-to-end delivary instead of the legacy NCP
• 1977 – Success to connect three different networks.
• 1978 – Split TCP into two protocols TCP and IP (TCP/IP)
• 1981 – Unix include TCP/IP as a network software on its operating system.
• 1983 – ARPANET split into two networks: MILNET for military users and
ARPANET for nonmilitary users.
• 1986 – NSFNET, a backbone that connected five supercomputer centers located
throughout the United States.
• 1990 – ARPANET was officially retired and replaced by NSFNET
• 1991 – The establishment of nonprofit organization called Advanced Network and
Services (ANS) to build a new, high-speed Internet backbone
• 1995 – Companies known as Internet Service Providers (ISPs) started
Internet Today
The Internet today is not a simple hierarchical structure. It is made up
of many wide and local area networks joined by connecting devices and
switching stations.
1-2 PROTOCOLS AND STANDARDS
In this section, we define two widely used terms:
protocols and standards. First, we define protocol,
which is synonymous with “rule.” Then we discuss
standards, which are agreed-upon rules.
PROTOCOLS
Protocol is a set of rules that define What is communicated, How it’s
communicated and When it is communicated
Communication between two people or two devices needs to follow some protocol
Hi
TCP connection
request
Hi
TCP connection
response
Got the
time?
GET
http://gaia.cs.umass.edu/kurose_ross
2:00
<file>
time
Human
Communication
Protocol
Computer Network
Communication
Protocol
PROTOCOLS
Protocol key elements are:
Syntax
• Refers to the Structure or the formatting of the data
and the order they are presented
• Refers to the meaning of each section of bits. How is
a particular pattern to be interpreted, and what
Semantic
action is to be taken based on that interpretation
Timimg
• Refers to two characteristics: when data should be
sent and how fast it can be sent
STANDARDS
Standards are essential in creating and maintaining an open and
competitive market for equipment manufacturers and also in
guaranteeing national and international interoperability of data
and telecommunications technology and processes.
De-Facto
De-Jure
• (meaning “by fact” or “by convention”)
• have not been approved by an organized body but have
been adopted as standards through widespread use
• meaning “by law” or “by regulation”
• have been legislated by an officially recognized body
1-3 STANDARDS ORGANIZATION
Standards are developed through the cooperation of standards
creation committees, forums, and government regulatory
agencies.
Standards Creation Committees
• International Standards Organization (ISO)
• International Telecommunications Union–Telecommunications
Standards Sector (ITU-T)
• American National Standards Institute (ANSI)
• Institute of Electrical and Electronics Engineers (IEEE)
• Electronic Industries Association (EIA)
• World Wide Web Consortium (W3C)
• Open Mobile Alliance (OMA)
1-4 INTERNET STANDARDS
An Internet standard is a thoroughly tested specification that
is useful to and adhered to by those who work with the
Internet. It is a formalized regulation that must be followed.
There is a strict procedure by which a specification attains
Internet standard status. A specification begins as an Internet
draft. An Internet draft is a working document with no official
status and a six-month lifetime. Upon recommendation from
theInternet authorities, a draft may be published as a Request
for Comment (RFC). Each RFC is edited, assigned a number,
and made available to all interested parties.
Maturity levels of an RFC
An RFC, during its lifetime, falls into one of six maturity levels: proposed
standard, draft standard, Internet standard, historic, experimental, and
informational
Requirement levels of an RFC
RFCs are classified into five requirement levels:
1-5 INTERNET ADMINISTRATION
Internet Society (ISOC)
The Internet Society (ISOC) is an international, nonprofit
organization formed in 1992 to provide support for the Internet
standards process. ISOC accomplishes this through maintaining
and supporting other Internet administrative bodies such as IAB,
IETF, IRTF, and IANA (see the following sections).
Internet administration