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CHAPTER 1 1.3 Interpret Reference Model of OSI and TCP/IP. - Coggle…
CHAPTER 1
1.3 Interpret Reference Model of OSI and TCP/IP.
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Types of Rules that are necessary to successfully communicate.
COMPUTER COMMUNICATION
Relationship between the Five Components
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Main elements of data communication systems
Message
It is the information to be communicated.
Popular forms of
information include text, pictures, audio, video and etc.
Receiver
It is the device which receives the data messages.
It can be a
computer, workstation, telephone handset etc.
Protocol
It is a set of rules that regulate data transmission. It is a contract between the communicating devices. Two devices may be connected but not communicating if they lack a protocol.
Transmission Medium
It is the physical path by which a message travels from sender to receiver. Some examples include twisted-pair wire, coaxial cable radio waves and etc.
Sender
It is the device which sends the data messages.
It can be a computer,
workstation, telephone handset and etc.
Rule Establishment
Protocols are necessary for effective communication and include:
◦ An identified sender and receiver.
◦ Common language and grammar
◦ Speed and timing of delivery
◦ Confirmation or acknowledgment requirements
Protocols used in network communications also define:
◦ Message encoding
◦ Message delivery options
◦ Message Formatting and Encapsulation
◦ Message Timing
◦ Message Size
Message Encoding
The format of encoding between hosts must be mild. :CHECK:
Messages are first converted into bits by the sending host. :CHECK:
Each bit is encoded into a pattern of sounds, light waves, or electrical impulses, depending on the network media. :CHECK:
The destination host receives and decodes the signals in order to interpret the message. :CHECK:
Message Formatting and Encapsulation
There is a standard format for letters and addressing letters that must be followed for proper delivery. :CHECK:
Encapsulation is the process of inserting a letter into an addressed envelope. :check:
Each computer message is encapsulated in a specific format known as a frame. :check:
A frame functions as an envelope, containing the destination and source addresses. :check:
Message Size
Humans break long messages into smaller parts or
sentences.
Long messages must also be broken into smaller
pieces to travel across a network. :star:
◦ Each piece is sent in a separate frame.
◦ Each frame has its own addressing information.
◦ A receiving host will reconstruct multiple frames into the original message.
Message Timing
Access Method
An access method defines the technique that is used to store and retrieve data
Response Timeout
Network hosts have rules that specify how long they should wait for responses and what action to take if a response timeout occurs.
Flow Control
Flow control is the control and monitoring of fluids in a process.
Message Delivery Options
Unicast Message
(One-to-one Delivery)
Broadcast Message
(One-to-all Delivery)
Multicast Message
(One-to-many Delivery)
All communication methods have three elements in common.
Destination (Receiver)
The destination receives the message and interprets it.
Channel (Media)
Provides the pathway over which the messagecan travel from source to destination.
Source (Sender)
Message sources are people, or electronic devices, that need to communicate a message to other individuals or devices.
Rules that Govern Communications
Protocol suites are implemented in software, hardware, or both by hosts and networking devices. :check:
The protocols are viewed in layers, with each higher-level service relying on the functionality defined by the lower-level protocols. :check:
Among the protocols for successful human
communication are:
Identification of sender and receiver.
Agreed-upon medium or channel (face-to-face, telephone, letter, photograph)
Appropriate communication mode (spoken, written, illustrated, interactive or one-way)
Common language
Grammar and sentence structure
Speed and timing of delivery
Network Protocols
Networking protocols define a standard format and set of rules for message exchange between devices.
Hypertext Transfer Protocol (HTTP), Transmission Control Protocol (TCP), and Internet Protocol are examples of common networking protocols (IP).
The role of protocols
How the message is formatted or structured.
The process by which networking devices share information about pathways with other networks.
How and when error and system messages are passed between devices.
The setup and termination of data transfer sessions.
Protocol Interaction
Communication between a web server and web client is an example of an interaction between several protocols:
TCP
Transport protocol that manages
the individual conversations.
IP
An IP address is a unique address that identifies a device on the internet or a local network.
HTTP
HTTP is the protocol used to transfer data over the web.
Ethernet
Allows communication over a data link and the physical transmission of data on the network media.
Protocol Suites and Industry Standards
A protocol suite is a collection of protocols that work together to provide full network communication services.
◦ May be specified by a standards organization or developed by a vendor.
Development of TCP/IP
Advanced Research Projects Agency Network (ARPANET) was the predecessor to today’s Internet.
TCP/IP Protocol Suite
TCP/IP Communication Process
The HTTP application layer protocol sends the data to the transport layer.
The transport layer breaks the data
into segments and identifies each.
Next the IP source and destination addresses are added, creating an IP Packet.
The Ethernet information is then added creating the Ethernet Frame, or data link frame.
When receiving the data link frames from the web server, the client processes and removes each protocol header in the opposite order it was added:
◦ First the Ethernet header is removed. :check:
◦ Then the IP header :check:
◦ Then the Transport layer header. :check:
◦ Finally the HTTP information is processed. :check:
The Benefits of Using a Layered Model
:<3: Assisting in protocol design
since protocols at each layer
:<3: Fostering competition
:<3: Preventing technology changes
:<3: Providing a common language
The OSI Reference Model
Application - contains protocols used for process-to-
Presentation - provides for common representation of the data.
Session - provides services to the presentation layer to organize its dialogue and to manage data exchange.
Transport - defines services to segment, transfer, and resemble the data.
Network - provides services to exchange the individual pieces of data.
Data Link - provides methods for exchanging data frames
Physical - describes the mechanical, electrical and functional, and procedural.
The 7 Layers of OSI
The TCP/IP Protocol Model
OSI Model and TCP/IP Model Comparison
Network access layer and application layer of TCP/IP model arefurther devided to discribe discrete functions.
Similarities & Differrences
