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CCNA Network Fundamentals. By: Hyder Hamandi. Chapter Two : Communicating over the Network. Elements of communication Source (encoding data before transmission) Transmission Media (Channel) Information sent Rules to control transmitting and receiving
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CCNA Network Fundamentals By: Hyder Hamandi
Chapter Two : Communicating over the Network • Elements of communication • Source (encoding data before transmission) • Transmission Media (Channel) • Information sent • Rules to control transmitting and receiving • Destination (decoding data after receiving)
Network Structure • Data is sent across a network in small “chunks” called segments One channel for different uses (multiplexing)
Network Structure • The components of a network • hardware • software
Network Structure • End Devices and their Role in the Network • End devices form interface with human network & communications network • Role of end devices: (like IP Phone, PC, Printer…) • client • server • both client and server
Network Structure • Devices In Between (Routers, Switches) • Provides connectivity between end devices • Manages data flow • Retransmit data
Network Structure Network media (types, criteria for choosing) • This is the channel over which a message travels
UTP (Unshielded Twisted Pair) Twisting provide : 1- protection against crosstalk, noise generated by adjacent pairs & 2- cancellation of the magnetic field. Based on connection layout, 3 types of UTP are existed: Straight UTP Cable Side1 : WO OWGBWBGWBrBr Side2 : WOOWGBWBGWBrBr Cross-Over UTP Cable Side1 : WO OWGBWBGWBrBr Side2 : WG GWOBWBOWBrBr Roll-Over UTP CableSide1 : WO OWGBWBGWBrBrSide2 : Br WBrGWBBWGOWO
Roll-Over UTP Cable or Console UTP Cable
Using of UTP Cables Roll-Over Cable consists of RJ-45 on one end & DB-9 on the other end. Conversion adapter from RJ-45 to DB-9 can be used with RJ-45 / RJ-45 Roll-over cable. Straight UTP Cable : Communicate between dissimilar devices (PC+Hub, PC+Switch, Switch+Router,) Cross–Over UTP Cable : Communicate between similar devices (PC+PC, Hub+Switch, Router+Router, PC+Router)
Factors for choosing Network Media • Resistance to Electromagnetic Interference (EMI) • Attenuation • Cost • Installation • Security Which cable has the highest attenuation? Coax, UTP, Fiber
Network Types • Local Area Networks (LANs) • - A network serving a home, building or campus is considered a Local Area Network (LAN) : Single Organization
Network Types • Wide Area Networks (WANs) • - LANs separated by geographic distance are connected by a network known as a Wide Area Network (WAN)
Network Types • The internet is defined as a global mesh of interconnectednetworks
Network Types • Network representations
Function of Protocol in Network Communication Network protocols are used • to allow devices to • communicate • successfully
Function of Protocol in Network Communication Different protocols and how they interact Protocols are hardware independent
Using Layers to describe net communication The net communication is a very complex process, if we looked at it as a whole. A simple way to understand this process is to break down the total net communication system into a series of layers. Each layer is responsible for a specific part of net comm. ISO (International Organization for Standardization) OSI/RM (Open System Interconnection) → 1984 It provided venders with a set of standards that insured greater compatibility between Net Tech. It has 7 numbered layers L1 : Physical, L2 : Data Link, L3 : Network, L4 : Transport, L5 : Session, L6 : Presentation, L7 : Application
Layers with TCP/IP and OSI Model • Define OSI Memorize name & no of layers
Advantages of Layering • Simple to develop • Simple to maintain • Simple to learn (understand) • Layers 7, 6, 5 deal with application • Layers 4, 3, 2, 1 deal with data transport
TCP/IP (Transmission Control Protocol / IP Protocol) This model is a suite of more than 10 protocols, distributed on 4 layers : Application, Transport, Internet & Network Access
Layers with TCP/IP and OSI Model • Compare OSI and TCP/IP model Theoretical Model Implemented Model
Name , number & briefly explain the layers of OSI model ? • Physical Layer : Binary Transmitting. • Data Link Layer : Physical Addressing. • Network Layer : IP Addressing. • Transport Layer : Reliable Communication. • Session Layer : Application Programs Communication. • Presentation Layer : Data Representation. • Application Layer : Application Programs Assisting.
Layers with TCP/IP and OSI Model • Encapsulation : • Identify data pieces of the sent msg • Ensure data pieces are transmitted to the destination • Enable reassembling data pieces Encapsulation Application, Presentation, Session → Data Transport → Segments Network → Packets Data Link → Frames Physical → Bits (Encoding)
Addressing and Naming Schemes • Labels in encapsulation headers are used to manage communication in data networks MAC in layer 2 ; Physical Add ; Device Add IP in layer 3 ; Logical Add Port No. in layer 4 : identify service (application)
PC Identifiers (Computer Name, Host Name, IP Add, MAC Add) • Computer Name : 256 characters (unique inside only , non standard) • Host Name : 256 characters (always unique , standard) • IP Address : 4 bytes (always unique , standard) • MAC Address : 6 bytes (always unique , standard) Which company supports computer name in communication?