The document discusses network architectures, protocols, and standards. It covers topics like network architecture, data communication protocols, protocol stacks, network protocol classifications, layered network architectures like OSI and TCP/IP, and standards organizations. It provides definitions and explanations of key concepts in data communications and computer networking.

1. Module 2
Datacom Network, Architecture,
Protocols, and Standards
Chapter 21
Electronic Communications Sytems , Fifth Editon
By: Wayne Tomasi
ECE @Saint Louis University, Baguio City 1
Prepared by: Engr. Jeffrey Des B. Binwag

2. Datacom Network, Architecture,
Protocols, and Standards
• Network Architecture. A system that outlines
the products and services necessary for the
individual components within a data
communications network to operate together.
It is a set of equipment, transmission media,
and procedures that ensures that a specific
sequence of events occurs in a network in the
proper order to produce the intended results.
ECE @Saint Louis University, Baguio City 2

3. Datacom Network, Architecture,
Protocols, and Standards
• Data Communications Protocol. Sets of rules
governing the orderly exchange of data within
the network or a portion of the network.
• Protocol Stack. The list of protocols used by a
system which normally includes one protocol
per layer.
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4. Datacom Network, Architecture,
Protocols, and Standards
• Network Protocol Clasification.
– Current. Most modern and sophisticated
– Legacy. Old but still useful
– Legendary. Old and no longer in use
• Computer Network General Classification.
– Broadcast. Involves all stations in the network
sharing the communications channel.
– Point to point. Involves only two stations at a time.
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5. Datacom Network, Architecture,
Protocols, and Standards
• Connection-Oriented Protocol.
– Requires a handshake prior to transmission
– Generally requires acknowledgement procedures
– Often provides an error control mechanism
– Connection is dropped by a specific handshake
when it is no longer needed
*Handshake. A connection procedure that ensures the
integrity of the connection between stations in a
network prior to the exchange of data between them.
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6. Datacom Network, Architecture,
Protocols, and Standards
• Connectionless Protocol.
–Does not require a handshake prior to
transmission
–Does not support error control or
acknowledgment procedures
–Is more efficient because the data being
transmitted do not justify the extra overhead
required by connection-oriented protocols
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7. Datacom Network, Architecture,
Protocols, and Standards
• Standard. An object or procedure considered by
an authority or by general consent as a basis of
comparison.
• Data Communications Standards. Guidelines
that have been generally accepted by the data
communications industry. They outline procedures
and equipment configurations that help ensure an
orderly transfer of information between two or
more data communication equipment of networks.
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8. Datacom Network, Architecture,
Protocols, and Standards
• Classification of Standards.
–Proprietary Standards. Closed system
standards generally manufactured or controlled
by one company.
–Open System Standards. Guidelines that can be
used by any company to produce compatible
equipment or software after a royalty has been
paid to the original company.
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9. Standards Organizations for Data
Communications
• ISO. International Standards Organization
• ITU-T. International Telecommunications Union-
Telecommunications Sector
• CCITT. Comité Consultatif Internationale de Télégraphie
et Téléphonie
• IEEE. Institute of Electrical and Electronics Engineers
• ANSI. American National Standards Institute
• EIA. Electronics Industry Association
• TIA. Telecommunications Industry Association
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10. Standards Organizations for Data
Communications
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ISO
ITU-T IEEE ANSI
EIA TIA

11. Standards Organizations for Data
Communications
• ITU-T Study Groups:
– Network and Service Operation
– Tariff and Accounting Principles
– Telecommunications Management Network and Network Interface
– Protection Against Electromagnetic Environment Effects
– Outside Plant
– Data Networks and Open Systems Communications
– Characteristics of Telematic Systems
– Television and Sound Transmission
– Language and General Software Aspects of Telecommunication Systems
– Signaling Requirements and Protocols
– End-to-end Transmission Performance of Networks and Terminals
– General Network Aspects
– Transport Networks, Systems, and Equipment
– Multimedia Services and Systems
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12. Standards Organizations for Data
Communications
• IAB. Internet Architecture Board
– Oversees Internet architecture protocols and procedures.
– Manages processes used to create Internet standards and serves as an
appeal board for complaints on the proper of execution of such
processes.
– Administers various Internet assigned numbers.
– Represents Internet Society interests in liaison relationships with other
organizations.
– Source of advice for guidance to the Internet Society concerning
technical, architectural, procedural, and policy matters concerning the
Internet and its enabling technologies.
• IETF. Internet Engineering Task Force
• IRTF. Internet Research Task Force
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13. Standards Organizations for Data
Communications
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IAB
IETF IRTF

14. Layered Network Architecture
• The layering of network responsibilities allows each layer to
add value to services provided by sets of lower layers.
• Layered architecture facililitates peer-to-peer network
protocols.
• Layered architecture allows different computers to
communicate at different levels.
• When technological advances occur, it is easier to modify
one layer’s protocol without having to modify all the other
layers.
• The disadvantage of layered architecture is the tremendous
amount of overhead required.
ECE @Saint Louis University, Baguio City 14

15. Layered Network Architecture
• Protocol Data Unit (PDU). A unit of data used to facilitate
seamless exchange of information between layers of the
protocol stack. Consists of a header and/or trailer
appended to the data as it passes through a layer.
• Encapsulation. The process of adding a protocol data unit
as the data frame passes from an upper layer to the layer
immediately below it. (Downward direction)
• Decapsulation. The process of removing a protocol data
unit as the data frame passes from a lower to the layer
immediately above it. (Upward direction)
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16. Popular Layered Protocols
• OSI (Open Systems Interconnection). A seven layer
protocol developed and adopted by the ISO and the ITU-T
in 1983.
• TCP-IP (Transmission Control Protocol/Internet Protocol).
A three or four layer protocol developed by the
Department of Defense of the United States before the
inception of the OSI model.
• CISCO THREE-LAYER MODEL. A Three-layer logical hierarchy
developed by CISCO that specifies where things belong,
how they fit together, and what functions go where.
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17. Open Systems Interconnection
 User networking applications and interfacing to
the network
 Encoding language used in transmission
 Job management tracking
 Data tracking as it moves through a network
 Network addressing and packet transmission on
the network
 Frame formatting for transmitting data across a
physical communications link
 Transmission method used to propagate bits
through a network
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LAYERS FUNCTIONS

18. Open Systems Interconnection
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TCP/IP

19. Open Systems Interconnection
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20. OSI and its Protocol Data Units
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21. TCP-IP Protocol Layers
• Network Access Layer. Provides a means of
physically delivering data packets using frames or
cells.
• Host-to-host Layer. Services the process and
Internet layers to handle the reliability and session
aspects of data transmission.
• Internet Layer. Contains information that pertains
to how data can be routed through the network.
• Process Layer. Provides applications support.
ECE @Saint Louis University, Baguio City 21

22. CISCO Protocol Layers
• Core Layer. Top layer responsible for transporting large
amounts of data traffic reliably and quickly. Primarily tasked
to switch traffic as quickly as possible.
• Distribution Layer/Workgroup Layer. The communication
point between the access and the core layers that provides
routing, filtering, WAN access, and control on the number
of data packets allowed to access the core layer.
• Access Layer/Desktop Layer. Responsible for access
control, segmentation (creation of collision domains), and
workgroup connectivity to the distribution layer.
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