Communicating over the Network : Communicating over the Network Network Fundamentals – Chapter 2
Objectives : Objectives Describe the structure of a network, including the devices and media that are necessary for successful communications.
Explain the function of protocols in network communications.
Explain the advantages of using a layered model to describe network functionality.
Describe the role of each layer in two recognized network models: The TCP/IP model and the OSI model.
Describe the importance of addressing in network communication.
Key Terms : Key Terms TCP/IP Model
OSI Model
Encapsulation
Protocol Data Units (PDU’s)
Encoding
Physical Addressing
Logical Addressing
Elements of Communication : Elements of Communication Three common elements of communication
message source
the channel
message destination
Define a Network
Data or information channels capable of carrying many different types of communications
How Messages are Communicated : How Messages are Communicated Data is sent across a network in small “chunks” called segments Ex: Time Division Multiplexing Note: term segmentation has several meanings
Components of Network Structure : Components of Network Structure Hardware
Software
Network End Devices : Network End Devices Role of end devices
Initiate data communications
Originate the flow of data
Final termination point for data flow
Common roles are client, server, or a combination
Network Intermediary Devices : Network Intermediary Devices Provides connectivity and ensures data flows across network
Some error reporting and reconfiguration of link failures
Aggregates connections to a network (switch, access point)
Provides path determination (routers)
Security based onpermits and denies
Network Media : Network Media Network media: channel over which a message travels
Choices for Network Media:
Network Types – LAN’s : Network Types – LAN’s Local Area Networks
- A network serving a home, building or campus is considered a Local Area Network (LAN) Geographic Proximity
Centralized Admin
Fast Links
Network Types – WAN’s : Network Types – WAN’s Wide Area Networks
- LANs separated by geographic distance are connected by a network known as a Wide Area Network (WAN) Geographic Distance
De-centralized Admin
Slower Links
Network Types - Internet : Network Types - Internet The Ultimate network
The Internet is defined as a global mesh of interconnected networks Intranet
Network Device/Media Icons : Network Device/Media Icons
Protocol Suites and Industry Standards : Protocol Suites and Industry Standards A standard is:
a process or protocol that has been endorsed by the networking industry and ratified by a standards organization
Function of Protocol in Network Communication : Function of Protocol in Network Communication Explain network protocols
Network protocols are used
to allow devices to
communicate
successfully
Protocol Stack : Protocol Stack Define different protocols and how they interact
Technology Independent Protocols : Technology Independent Protocols Network protocols specify, not the underlying technology to support this functionality
Different types of devices can communicate using the same sets of protocols.
Building Networks in Layers : Building Networks in Layers Benefits of layered models include:
Assists in protocol design
Fosters competition
Changes in one layer do not affect other layers
Provides a common language
TCP/IP Model : TCP/IP Model
Communication Between Layers : Communication Between Layers
Open Systems Interconnect (OSI) Model : Open Systems Interconnect (OSI) Model All
People
Some
Times
Need
Data
Processing All
People
Some
Times
Need
Data
Processing Away
Pizzas
Sausage
Throw
Not
Do
Please
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Comparing the TCP/IP and OSI Model : Comparing the TCP/IP and OSI Model
Encapsulation and Protocol Data Units : Encapsulation and Protocol Data Units Data must be organized in a logical order to make sense on the network
Question: How do we organize speech?
Different OSI layers require additional or appended information
Question: How do weorganize a book contents?
Encapsulation Steps – Top Down : Encapsulation Steps – Top Down
Another View of Protocol Encapsulation : Another View of Protocol Encapsulation Header
Contains details regarding destination device or network
Trailer
Supports error detection through mathematical comparisons
Addressing and Delivery in the Network : Addressing and Delivery in the Network Labels (addressing) in encapsulation headers are used to manage communication in data networks MAC IP Ports
Addressing and Naming Example : Addressing and Naming Example Encapsulation headers are used to manage communication in data networks
Communication Between Processes : Communication Between Processes Ports are used at the Transport Layer
Identifies the source and destination processes (or service) Download the movie from http://www.warriorsofthe.net
Chapter 2 Lab : Chapter 2 Lab Lab 2.2.4 – Network Representations and Packet Tracer Orientation
Lab 2.x - Using Wireshark
Slide 30 :