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Chapter Four

Communication Network Protocol

What is a Protocol?

A protocol is a set of rules that govern how systems communicate. I.e. it govern the format and
meaning of frames, messages or packets that are exchanged between the server and client.

Communication Protocol

 Communication protocols are formal descriptions of digital message formats and rules.
They are required to exchange messages in or between computing systems and are
required in telecommunications.
 Communications protocols cover authentication, error detection and correction, and
signaling. They can also describe the syntax, semantics, and synchronization of analog
and digital communications. Communications protocols are implemented in hardware
and software. There are thousands of communications protocols that are used everywhere
in analog and digital communications. Computer networks cannot exist without them.
 Communications devices have to agree on many physical aspects of the data to be
exchanged before successful transmission can take place. Rules defining transmissions
are called protocols.
 There are many properties of a transmission that a protocol can define. Common ones
include: packet size, transmission speed, error correction types, handshaking and
synchronization techniques, address mapping, acknowledgement processes, flow control,
packet sequence controls, routing, and address formatting

What does Network Protocols mean?

Network protocols are formal standards and policies comprised of rules, procedures and formats
that define communication between two or more devices over a network. Network protocols
govern the end-to-end processes of timely, secure and managed data or network communication.

Network protocols incorporate all the processes, requirements and constraints of initiating and
accomplishing communication between computers, servers, routers and other network-enabled
devices. Network protocols must be confirmed and installed by the sender and receiver to ensure
network/data communication and apply to software and hardware nodes that communicate on a
network.

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There are several broad types of networking protocols, including:

 Network communication protocols: Basic data communication protocols, such as TCP/IP

and HTTP.
 Network security protocols: Implement security over network communications and
include HTTPS, SSL and SFTP.
 Network management protocols: Provide network governance and maintenance and
include SNMP and ICMP.

Popular Protocols include: File Transfer Protocol (FTP), TCP/IP, User Datagram Protocol
(UDP), Hypertext Transfer Protocol (HTTP), Post Office Protocol (POP3), Internet Message
Access Protocol (IMAP), and Simple Mail Transfer Protocol (SMTP).

Reference Models in Communication Networks

The most important reference models are:

 OSI reference model.

 TCP/IP reference model.

Introduction to ISO-OSI Model

To ensure national and worldwide data communication ISO (ISO stands for International
Organization of Standardization.) developed this model. This is called a model for open system
interconnection (OSI) and is normally called as OSI model’s model architecture consists of
seven layers. It defines seven layers or levels in a complete communication system.

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The OSI Model - Features, Principles and Layers

There are n numbers of users who use computer network and are located over the world. So to
ensure, national and worldwide data communication, systems must be developed which are
compatible to communicate with each other ISO has developed a standard. ISO stands for
International organization of Standardization. This is called a model for Open System
Interconnection (OSI) and is commonly known as OSI model.

The ISO-OSI model is seven layer architecture. It defines seven layers or levels in a complete
communication system.

Below we have the complete representation of the OSI model, showcasing all the layers and how
they communicate with each other.

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Feature of OSI Model

 Big picture of communication over network is understandable through this OSI model.
 We see how hardware and software work together.
 We can understand new technologies as they are developed.
 Troubleshooting is easier by separate networks.
 Can be used to compare basic functional relationships on different networks.

Principles of OSI Reference Model

The OSI reference model has 7 layers. The principles that were applied to arrive at the seven
layers can be briefly summarized as follows:

o A layer should be created where a different abstraction is needed.

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o Each layer should perform a well-defined function.

o The function of each layer should be chosen with an eye toward defining internationally
standardized protocols.
o The layer boundaries should be chosen to minimize the information flow across the
interfaces.
o The number of layers should be large enough that distinct functions need not be thrown
together in the same layer out of necessity and small enough that architecture does not
become unwieldly.

Layers of OSI Reference Model

In the table below, we have specified the protocols used and the data unit exchanged by each
layer of the OSI Model.

Functions of Different Layers

OSI Model Layer 1: The Physical Layer

Functions of Physical Layer

Following are the various functions performed by the Physical layer of the OSI model.

 Representation of Bits: Data in this layer consists of stream of bits. The bits must be
encoded into signals for transmission. It defines the type of encoding i.e. how 0's and 1's
are changed to signal.
 Data Rate: This layer defines the rate of transmission which is the number of bits per
second.
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 Synchronization: It deals with the synchronization of the transmitter and receiver. The
sender and receiver are synchronized at bit level.
 Interface: The physical layer defines the transmission interface between devices and
transmission medium.
 Line Configuration: This layer connects devices with the medium: Point to Point
configuration and Multipoint configuration.
 Topologies: Devices must be connected using the following topologies: Mesh, Star, Ring
and Bus.
 Transmission Modes: Physical Layer defines the direction of transmission between two
devices: Simplex, Half Duplex, and Full Duplex.
 Deals with baseband and broadband transmission.

Design Issues with Physical Layer

 The Physical Layer is concerned with transmitting raw bits over a communication
channel.
 The design issue has to do with making sure that when one side sends a 1 bit, it is
received by the other side as a 1 bit and not as a 0.
 The design issues here largely deal with mechanical, electrical and timing interfaces, and
the physical transmission medium, which lies below the physical layer.

OSI Model Layer 2: Data Link Layer

Functions of Data Link Layer

 Framing: Frames are the streams of bits received from the network layer into
manageable data units. This division of stream of bits is done by Data Link Layer.
 Physical Addressing: The Data Link layer adds a header to the frame in order to define
physical address of the sender or receiver of the frame, if the frames are to be distributed
to different systems on the network.
 Flow Control: A flow control mechanism to avoid a fast transmitter from running a slow
receiver by buffering the extra bit is provided by flow control. This prevents traffic jam at
the receiver side.

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 Error Control: Error control is achieved by adding a trailer at the end of the frame.
Duplication of frames are also prevented by using this mechanism. Data Link Layers
adds mechanism to prevent duplication of frames.
 Access Control: Protocols of this layer determine which of the devices has control over
the link at any given time, when two or more devices are connected to the same link.

Design Issues with Data Link Layer

o The issue that arises in the data link layer (and most of the higher layers as well) is how
to keep a fast transmitter from drowning a slow receiver in data. Some traffic regulation
mechanism is often needed to let the transmitter know how much buffer space the
receiver has at the moment. Frequently, the flow regulation and the error handling are
integrated.
o Broadcast networks have an additional issue in the data link layer: How to control access
to the shared channel. A special sublayer of the data link layer, the Medium Access
Control (MAC) sublayer, deals with this problem.

OSI Model Layer 3: The Network Layer

Functions of Network Layer

 It translates logical network address into physical address. Concerned with circuit,
message or packet switching.
 Routers and gateways operate in the network layer. Mechanism is provided by Network
Layer for routing the packets to final destination.
 Connection services are provided including network layer flow control, network layer
error control and packet sequence control.
 Network Layer routes the signal through different channels from one node to other.
 It acts as a network controller. It manages the Subnet traffic.
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 The network Layer controls the operation of the subnet. The main aim of this layer is to
deliver packets from source to destination across multiple links (networks). If two
computers (system) are connected on the same link, then there is no need for a network
layer. It routes the signal through different channels to the other end and acts as a
network controller.
 It also divides the outgoing messages into packets and to assemble incoming packets into
messages for higher levels.
 In broadcast networks, the routing problem is simple, so the network layer is often thin or
even non-existent.

Design Issues with Network Layer

o A key design issue is determining how packets are routed from source to destination.
Routes can be based on static tables that are wired into the network and rarely changed.
They can also be highly dynamic, being determined anew for each packet, to reflect the
current network load.
o If too many packets are present in the subnet at the same time, they will get into one
another's way, forming bottlenecks. The control of such congestion also belongs to the
network layer.
o Moreover, the quality of service provided (delay, transmit time, jitter, etc) is also a
network layer issue.
o When a packet has to travel from one network to another to get to its destination,
many problems can arise such as:
o The addressing used by the second network may be different from the first one.
o The second one may not accept the packet at all because it is too large.
o The protocols may differ, and so on.
o It is up to the network layer to overcome all these problems to allow heterogeneous
networks to be interconnected.

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OSI Model Layer 4: Transport Layer

 Transport Layer decides if data transmission should be on parallel path or single path.
 Transport layer can be very complex, depending upon the network requirements.
 Transport layer breaks the message (data) into small units so that they are handled more
efficiently by the network layer.
 The basic function of the Transport layer is to accept data from the layer above, split it up
into smaller units, pass these data units to the Network layer, and ensure that all the
pieces arrive correctly at the other end.
 The most popular type of transport connection is an error-free point-to-point channel
that delivers messages or bytes in the order in which they were sent.
 The Transport layer is a true end-to-end layer, all the way from the source to the
destination.

Functions of Transport Layer

1. Service Point Addressing: Transport Layer header includes service point address which
is port address. This layer gets the message to the correct process on the computer unlike
Network Layer, which gets each packet to the correct computer.
2. Segmentation and Reassembling: A message is divided into segments; each segment
contains sequence number, which enables this layer in reassembling the message.
Message is reassembled correctly upon arrival at the destination and replaces packets
which were lost in transmission.
3. Connection Control: It includes 2 types:
o Connectionless Transport Layer: Each segment is considered as an independent
packet and delivered to the transport layer at the destination machine.
o Connection Oriented Transport Layer: Before delivering packets, connection
is made with transport layer at the destination machine.
4. Flow Control: In this layer, flow control is performed end to end.
5. Error Control: Error Control is performed end to end in this layer to ensure that the
complete message arrives at the receiving transport layer without any error. Error
Correction is done through retransmission.

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Design Issues with Transport Layer

 Accepting data from Session layer, split it into segments and send to the network layer.
 Ensure correct delivery of data with efficiency.
 Isolate upper layers from the technological changes.
 Error control and flow control.

OSI Model Layer 5: Session Layer

 Session Layer manages and synchronizes the conversation between two different
applications.
 Transfer of data from source to destination session layer streams of data are marked and
are resynchronized properly, so that the ends of the messages are not cut prematurely and
data loss is avoided.
 It allows users on different machines to establish active communication sessions between
them.
 Its main aim is to establish, maintain and synchronize the interaction between
communicating systems.

Functions of Session Layer

1. Dialog Control: This layer allows two systems to start communication with each other in
half-duplex or full-duplex.
2. Token Management: This layer prevents two parties from attempting the same critical
operation at the same time.
3. Synchronization: allows a process to add checkpoints which are considered as
synchronization points into stream of data.

Example: If a system is sending a file of 800 pages, adding checkpoints after every 50 pages
is recommended. This ensures that 50 page unit is successfully received and acknowledged.
This is beneficial at the time of crash as if a crash happens at page number 110; there is no
need to retransmit 1 to100 pages.

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Design Issues with Session Layer

 To allow machines to establish sessions between them in a seamless fashion.

 Provide enhanced services to the user.
 To manage dialog control.
 To provide services such as Token management and Synchronization.

OSI Model Layer 6: Presentation Layer

 Presentation Layer takes care that the data is sent in such a way that the receiver will
understand the information (data) and will be able to use the data.
 While receiving the data, presentation layer transforms the data to be ready for the
application layer.
 Languages (syntax) can be different of the two communicating systems. Under this
condition presentation layer plays a role of translator.
 It performs Data compression, Data encryption, Data conversion etc.
 The primary goal of this layer is to take care of the syntax and semantics of the
information exchanged between two communicating systems.
 In order to make it possible for computers with different data representations to
communicate, the data structures to be exchanged can be defined in an abstract way. The
presentation layer manages these abstract data structures and allows higher-level data
structures (eg: banking records), to be defined and exchanged.

Functions of Presentation Layer

1. Translation: Before being transmitted, information in the form of characters and

numbers should be changed to bit streams. The presentation layer is responsible for
interoperability between encoding methods as different computers use different encoding
methods. It translates data between the formats the network requires and the format the
computer.
2. Encryption: It carries out encryption at the transmitter and decryption at the receiver.
3. Compression: It carries out data compression to reduce the bandwidth of the data to be
transmitted. The primary role of Data compression is to reduce the number of bits to be
0transmitted. It is important in transmitting multimedia such as audio, video, text etc.

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Design Issues with Presentation Layer

 To manage and maintain the Syntax and Semantics of the information transmitted.
 Encoding data in a standard agreed upon way. Eg: String, double, date, etc.
 Perform Standard Encoding on wire.

OSI Model Layer 7: Application Layer

 Application Layer is the topmost layer.

 Transferring of files disturbing the results to the user is also done in this layer. Mail
services, directory services, network resource etc. are services provided by application
layer.
 This layer mainly holds application programs to act upon the received and to be sent data.
 The Application Layer contains a variety of protocols that are commonly needed by
users. One widely-used application protocol is HTTP (Hypertext Transfer Protocol),
which is the basis for the World Wide Web. When a browser wants a web page, it sends
the name of the page it wants to the server using HTTP. The server then sends the page
back.
 Other Application protocols that are used are: File Transfer Protocol (FTP), Trivial
File Transfer Protocol (TFTP), Simple Mail Transfer Protocol (SMTP), TELNET,
Domain Name System (DNS) etc.

Functions of Application Layer

1. Mail Services: This layer provides the basis for E-mail forwarding and storage.
2. Network Virtual Terminal: It allows a user to log on to a remote host. The application
creates software emulation of a terminal at the remote host. User's computer talks to the
software terminal which in turn talks to the host and vice versa. Then the remote host
believes it is communicating with one of its own terminals and allows user to log on.
3. Directory Services: This layer provides access for global information about various
services.

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4. File Transfer, Access and Management (FTAM): It is a standard mechanism to access

files and manages it. Users can access files in a remote computer and manage it. They can
also retrieve files from a remote computer.

Design Issues with Application Layer

There are commonly reoccurring problems that occur in the design and implementation of
Application Layer protocols and can be addressed by patterns from several different pattern
languages:

 Pattern Language for Application-level Communication Protocols

 Service Design Patterns
 Patterns of Enterprise Application Architecture
 Pattern-Oriented Software Architecture

Merits of OSI reference model

 OSI model distinguishes well between the services, interfaces and protocols.
 Protocols of OSI model are very well hidden.
 Protocols can be replaced by new protocols as technology changes.
 Supports connection-oriented services as well as connectionless service.

Demerits of OSI reference model

Model was devised before the invention of protocols.

Fitting of protocols is tedious task.
It is just used as a reference model.

TCP/IP Reference Model

TCP/IP stands for Transmission Control Protocol/Internet Protocol. TCP/IP is a set of

layered protocols used for communication over the Internet. The communication model of this
suite is client-server model. A computer that sends a request is the client and a computer to
which the request is sent is the server. Protocols are set of rules which govern every possible

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communication over a network. These protocols describe the movement of data between the
source and destination or the internet. They also offer simple naming and addressing schemes.

The features that stood out during the research, which led to making the TCP/IP reference model
were:

 Support for a flexible architecture. Adding more machines to a network was easy.
 The network was robust, and connections remained intact until the source and destination
machines were functioning.

The overall idea was to allow one application on one computer to talk to (send data packets)
another application running on different computer.

Protocols and networks in the TCP/IP model:

Different Layers of TCP/IP Reference Model

Layer 1: Network Access Layer

 Lowest layer of the all.

 The Network Access Layer in the TCP/IP model performs the same functions as Layers
1 and 2 of the OSI model, the Physical and Data Link layers.
 Protocol is used to connect to the host, so that the packets can be sent over it.
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 Varies from host to host and network to network.

 Actual data transmission in bits occurs at the data link layer using the destination address
provided by network layer.

Layer 2: Internet layer

The TCP/IP Internet layer is equivalent to the Network layer in the OSI model.

Selection of a packet switching network which is based on a connectionless internetwork

layer is called an internet layer.
Network layer connection is established using Internet Protocol (IP) at the network layer.
Every machine connected to the Internet is assigned an address called IP address by the
protocol to easily identify source and destination machines.
It is the layer which holds the whole architecture together.
It helps the packet to travel independently to the destination.
Order in which packets are received is different from the way they are sent.
IP (Internet Protocol) is used in this layer.
The various functions performed by the Internet Layer are:

o Delivering IP packets
o Performing routing
o Avoiding congestion

Layer 3: Transport Layer

 The Transport layer is the next layer up in both models. In the OSI model it was
originally was referred to as the Host-to-Host layer.
 It decides if data transmission should be on parallel path or single path.
 Functions such as multiplexing, segmenting or splitting on the data is done by transport
layer.
 Data is transmitted in form of datagrams using the Transmission Control Protocol (TCP).
 TCP is responsible for breaking up data at the client side and then reassembling it on the
server side.
 The applications can read and write to the transport layer.
 Transport layer adds header information to the data.
 Transport layer breaks the message (data) into small units so that they are handled more
efficiently by the network layer.
 Transport layer also arrange the packets to be sent, in sequence.

Layer 4: Application Layer

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 The Application layer in the OSI model is equivalent to the top three layers of the OSI
model, the Session, Presentation and Application layers.

The TCP/IP specifications described a lot of applications that were at the top of the protocol
stack. Some of them were TELNET, FTP, SMTP, DNS etc.

 TELNET is a two-way communication protocol which allows connecting to a remote

machine and run applications on it.
 FTP (File Transfer Protocol) is a protocol that allows File transfer amongst computer
users connected over a network. It is reliable, simple and efficient.
 SMTP (Simple Mail Transport Protocol) is a protocol, which is used to transport
electronic mail between a source and destination, directed via a route.
 DNS (Domain Name Server) resolves an IP address into a textual address for Hosts
connected over a network.
 It allows peer entities to carry conversation.
 It defines two end-to-end protocols: TCP and UDP

o TCP (Transmission Control Protocol): It is a reliable connection-oriented

protocol which handles byte-stream from source to destination without error and
flow control.
o UDP (User-Datagram Protocol): It is an unreliable connection-less protocol that
do not want TCPs, sequencing and flow control. Eg: One-shot request-reply kind
of service.

Merits of TCP/IP model

 It operated independently.
 It is scalable.
 Client/server architecture.
 Supports a number of routing protocols.
 Can be used to establish a connection between two computers.

Demerits of TCP/IP

 In this, the transport layer does not guarantee delivery of packets.

 The model cannot be used in any other application.
 Replacing protocol is not easy.
 It has not clearly separated its services, interfaces and protocols.

TCP/IP suite of protocols

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The TCP/IP suite is a set of protocols used on computer networks today (most notably on the
Internet). It provides an end-to-end connectivity by specifying how data should be packetized,
addressed, transmitted, routed and received on a TCP/IP network. This functionality is organized
into four abstraction layers and each protocol in the suite resides in a particular layer.

The TCP/IP suite is named after its most important protocols, the Transmission Control Protocol
(TCP) and the Internet Protocol (IP). Some of the protocols included in the TCP/IP suite are:

ARP (Address Resolution Protocol) – It used to translate an IP address to a MAC or

physical address. (IP4 networks)
IP (Internet Protocol) – used to deliver packets from the source host to the destination
host based on the IP addresses. This is the main networking protocol. There are two
version of IP (IPv4 and IPV6).
ICMP (Internet Control Message Protocol) – used to detects and reports network error
conditions. Used in ping.
TCP (Transmission Control Protocol) – a connection-oriented protocol that enables
reliable data transfer between two computers i.e. it provide a reliable end to end
connection.
UDP (User Datagram Protocol) – a connectionless protocol for data transfer. Since a
session is not created before the data transfer, there is no guarantee of data delivery. UDP
is used more in utility applications like DNS, RIP (routing information protocol), and
DHCP.
FTP (File Transfer Protocol) – used for file transfers from one host to another.
Telnet (Telecommunications Network) – used to connect and issue commands on a
remote computer.
DNS (Domain Name System) – used for host names to the IP address resolution.
HTTP (Hypertext Transfer Protocol) – used to transfer files (text, graphic images,
sound, video, and other multimedia files) on the World Wide Web.
SMTP, POP3, IMap4 – These are email protocols
Applications will choose which transmission protocol to use based on their function.
HTTP, POP3, IMAP4, SMTP and many more use TCP.

The following table shows which protocols reside on which layer of the TCP/IP model:

Layer Protocol
Application Layer HTTP,NFS,DNS,Telnet,FTP,SNMP,SMTP,POP3
Transport Layer TCP,UDP
Internet Layer IP (IPv4,IPv6),ARP,ICMP
Network Access Layer Ethernet, IEEE 802.3,Token Ring, FDDI

Comparison of OSI and TCP/IP Reference Model

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Following are some similarities between OSI Reference Model and TCP/IP Reference Model.

 Both have layered architecture.

 Layers provide similar functionalities.
 Both are protocol stack.
 Both are reference models.

Difference between OSI and TCP/IP Reference Model

TCP/IP(Transmission Control Protocol /

OSI(Open System Interconnection)
Internet Protocol)
TCP/IP model is based on standard protocols
OSI is a generic, protocol independent standard,
around which the Internet has developed. It is a
acting as a communication gateway between the
communication protocol, which allows
network and end user.
connection of hosts over a network.
In TCP/IP model the transport layer does not
In OSI model the transport layer guarantees the
guarantees delivery of packets. Still the TCP/IP
delivery of packets.
model is more reliable.
Follows vertical approach. Follows horizontal approach.
OSI model has a separate Presentation layer and TCP/IP does not have a separate Presentation
Session layer. layer or Session layer.
Transport Layer is both Connection Oriented and
Transport Layer is Connection Oriented.
Connection less.
Network Layer is both Connection Oriented and
Network Layer is Connection less.
Connection less.
OSI is a reference model around which the
TCP/IP model is, in a way implementation of the
networks are built. Generally it is used as a
OSI model.
guidance tool.
Network layer of OSI model provides both The Network layer in TCP/IP model provides
connection oriented and connectionless service. connectionless service.
OSI model has a problem of fitting the protocols
TCP/IP model does not fit any protocol
into the model.
Protocols are hidden in OSI model and are easily
In TCP/IP replacing protocol is not easy.
replaced as the technology changes.
OSI model defines services, interfaces and In TCP/IP, services, interfaces and protocols are
protocols very clearly and makes clear distinction not clearly separated. It is also protocol
between them. It is protocol independent. dependent.
It has 7 layers It has 4 layers

Network Standard and Standardization Bodies

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Standards

Why do we need standards?

 To create and maintain an open and competitive market for equipment manufacturers
 To guarantee national and international interoperability of data, telecommunication
technology and process
 To give a fixed quality and product to the customer
 To allow the same product to be reused again elsewhere
 To aid the design and implementation of ideas
 To provide guidelines to manufacturers, vendors, government agencies and other service
providers to ensure kind of interconnectivity.

Data communication standards are divided into two categories

De facto (from the fact):
 Standards that have not been approved by an organized body.
 It has been adopted as standards through widespread use.
 This is often established originally by manufacturers to define the functionality of a new
product or technology.
De jure (by law):
 Those that have been legislated by an officially recognized body.
Standards organizations
Standards are developed through the cooperation of standards creation committees, forums, and
government regulatory agencies.

Networking Standardization bodies

The rise of open standards not owned by any one company has been a great boon to customers of
computer and networking products, as well as the manufacturers that sell to them. In order to
facilitate the development of open standards, however, organizations are needed that will
coordinate the creation and publishing of these documents. Generally, these are non-profit
organizations that specifically take a neutral stance regarding technologies and work for the
betterment of the industry as a whole.

Key Concept: There are a number of well-known international organizations that play an
important role in the development of open networking standards. Some of the most
important of these are ISO, ANSI, ITIC, IEEE, EIA/TIA, ITU-T and ETSI. These are oversight
organizations, responsible for overall management of the standards development process, rather
than for the particulars of creating individual standards.

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Here are some of the standards organizations are:

International Organization for Standardization (ISO): It is active in developing cooperation

in the realms of scientific, technological and economic activity.

o Probably the biggest standards organization in the world, the ISO is really a federation of
standards organizations from dozens of nations. In the networking world, the ISO is best
known for its OSI Reference Model.

American National Standards Institute (ANSI):

o It is the main organization responsible for coordinating and publishing computer and
information technology standards in the United States.

Information Technology Industry Council (ITIC):

o ITIC is a group of several dozen companies in the information technology (computer)

industry. It was formerly known as the Computer and Business Equipment Manufacturers
Association (CBEMA).

National Committee for Information Technology (NCITS):

o A committee established by the ITIC to develop and maintain standards related to the
information technology world. NCITS was formerly known by the name Accredited
Standards Committee X3, Information Technology, or more commonly, just X3. It
maintains several sub-committees that develop and maintain standards for various
technical subjects.

Institute of Electrical and Electronics Engineers (IEEE):

o It aims to advance theory, creativity, and product quality in the fields of electrical
engineering, electronics radio and in all related branches of Engineering.
o It oversees the development and adoption of international standards for computing and
communications.
o The IEEE (pronounced “eye-triple-eye”) is a well-known professional organization for
those in the electrical or electronics fields, including computers and networking. IEEE's
main claim to fame in the networking industry is the IEEE 802 Project, which
encompasses many popular networking technologies including Ethernet.

Electronic Industries Alliance (EIA):

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DC&CN Chapter 4 Lecture Note Prepared by Abraham A.
Wolkite University College of Computing and Informatics Department of IT

o It is a nonprofit organization devoted to the promotion of electronics manufacturing

concerns.
o The EIA is an international industry association that is best known for publishing
electrical wiring and transmission standards.

o Its activities include public awareness education and lobbying efforts in addition to
standards development.

o It also made significant contributions by defining physical connection interfaces and

electronic signaling specifications for data communication.

Telecommunications Industry Association (TIA):

o The TIA is the communications sector of the EIA, and is responsible for developing
communications standards. Since communications, wiring and transmission are all
related, and since the TIA and EIA organizations are also related, standards produced by
the EIA or TIA are often labeled with the combined prefixes “EIA/TIA” or “TIA/EIA”.

International Telecommunication Union -

o It is a standard for telecommunication in general and data systems in particular.

European Telecommunications Standards Institute (ETSI):

o An organization with members from dozens of countries both within and outside Europe
that is dedicated to developing telecommunications standards for the European market
(and elsewhere). ETSI is known for, among other things, regulating the use of radio
bandwidth in Europe and developing standards such as Hyper LAN.

Forums
 It work with universities and users to test, evaluate, and standardize new technologies.
 The forums are able to speed acceptance and use of those technologies in the
telecommunications community.
 It presents their conclusions to standard bodies.
Regulatory Agencies:
 Its purpose is to protect the public interest by regulating radio, television and wire cable
communications.
 It has authority over interstate and international commerce as it relates to communication.

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DC&CN Chapter 4 Lecture Note Prepared by Abraham A.