Transcript 01_tcom5272_intro

TCOM 5272
Telecomm Lab
Dr. Mostafa Dahshan
OU-Tulsa 4W 2nd floor
660-3713
[email protected]
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Acknowledgments
 Most of the contents of this
presentation are imported from
 Supplemental materials of the textbook
 Presentations of Dr. Anindya Das
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Introduction
 Course Objectives
 Implementation of the theory
 Improve knowledge in network devices
management
 Introduce some useful software tools
 Schedule
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Network Types
 Local area networks (LANs)
 Metropolitan area networks (MANs)
 Wide area networks (WANs)
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LAN (Local Area Network)
 Interconnects
computers, printers,
other equipment
 Consists of shared
hardware and software
resources in close
physical proximity
 Example: TCOM
Department
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MAN (Metropolitan Area Network)
 Spans a greater
distance than a LAN
 Links multiple LANs
within city or
metropolitan region
 Typically uses fiberoptic/wireless
connections
 Example: Campus LAN
links to offices outside
the campus
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WAN (Wide Area Network)
 Composed of two or
more LANs or MANs
 May have constituent
LANs on different
continents
 Example: The Internet
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Network Topologies
 Main topologies:
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Bus
Ring
Star
Mesh
 Hybrid topologies
 star-bus
 star-ring
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Bus Topology
 Consists of cables connecting
PCs or file servers
 Visualizes connections as chain
links
 Terminator attached to each
end of bus cable segment
 Media type (discussed later)
 10Base5
 10Base2
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Bus Topology (2)
 Advantages
 Requires less cable than other topologies
 Easy to extend bus with a workstation
 Disadvantages
 High management costs
 Single defective node can take down entire network
 Can become quickly congested with
network traffic
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Ring Topology
 Continuous data path
 Workstations attached to cable
at points around ring
 Transmitted data
 Goes around ring to reach
destination
 Continues until ends at source
node
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Ring Topology (2)
 Advantages
 Easier to manage than bus
 Handles high volume network better
than bus
 Suited to transmitting signals over long
distances
 Disadvantages
 Expensive equipment and wiring
 Fewer equipment options
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Star Topology
 Multiple nodes attached to
central device (hub, switch,
router)
 Cable segments radiate
from center like a star
 Example: workstations
connected to switch
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Star Topology (2)
 Advantages
 Easier to manage, defective nodes
quickly isolated
 Easier to expand
 Better equipment and high-speed
options
 Disadvantages
 Failure of central device may cause
network failure
 Requires more cable than bus
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Mesh Topology
 Every node connected
to every other node in
network
 Often used in MANs and
WANs
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Mesh Topology (2)
 Advantages
 Fault tolerance
 Alternate communication paths
 Disadvantages
 Expensive
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The ISO Reference Model
 Fundamental network communications
model
 Product of two standards organizations
 International Organization for Standardization
(ISO)
 American National Standards Institute (ANSI)
 OSI is theoretical, not specific hardware or
software
 OSI guidelines analogized to a grammar
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The ISO Reference Model (2)
 Accomplishments
 Enabling communications among LANs,
MANs, WANs
 Standardizing network equipment
 Enabling backward compatibility to
protect investments
 Enabling development of software and
hardware with common interfaces
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The ISO Reference Model (3)
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Layered Model
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Reduces complexity
Standardizes interfaces
Facilitates modular engineering
Ensures interoperable technology
Accelerates evolution
Simplifies teaching & learning
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Physical Layer
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Transmit and receive signals
Network connectors
Signaling and encoding methods
Detection of signaling errors
Data transfer mediums
 wire cable
 fiber optics
 radio waves
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Data Link Layer
 Format bits into frames
 Frame: discrete unit of information
 Contains control and address information
 Does not contain routing information
 Logical Link Control (LLC)
 Initiates communication between two nodes
 Media Access Control (MAC)
 Provides physical addressing
 Regulates access to the media
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Network Layer
Packet logical addressing
Path determination
Route optimization
Addressing is done through routed
protocols: IP, IPX, AppleTalk, DECnet
 Path Selection is done using routing
protocols: RIP, IGRP, EIGRP, OSPF,
BGP
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Transport Layer
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Provides transparent flow of data
End-to-end recovery
Flow control and error control
Data segmentation
Ensures data received in order
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Session Layer
 Manages dialog between applications
 Establishes, manages, terminates
sessions
 Determines communication type
 Simplex
 Half-duplex
 Full-duplex
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Presentation Layer
 Provides data representation and
code formatting
 Translates between character codes
 Compression and encryption
 Example: Secure Sockets Layer (SSL)
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Application Layer
 Provides network services to
applications
 Remote access to printers
 Message handling for electronic mail
 Terminal emulation
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Internet Standards
 Specifications of network technologies
 Ratified by the IETF
 Begins as
 Internet Draft (ID)
 Request For Comments (RFC)
 Not all RFCs are standards
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Internet Standards (2)
 Examples of full standard RFCs
 RFC 791: Internet Protocol
 RFC 793: Transmission Control Protocol
 RFC 959: File Transfer Protocol
 Full List
www.apps.ietf.org/rfc/stdlist.html
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Media Types
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Coaxial cable: copper wire
Twisted-pair cable: copper wire
Fiber-optic cable: glass or plastic
Wireless: radio or microwaves
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Coaxial Cables
 Used in bus topologies
 10Base5 (thicknet, thickwire, RG8)
 10Base2 (thinnet, thinwire)
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10Base5
 Transmission rate of 10 Mbps
 Longest cable run 500 m
 Two transmission types
 Baseband: single channel
 Broadband: multiple nodes on multiple channels
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10Base5 (2)
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Has relatively large 0.4-inch diameter
Copper or copper-clad aluminum conductor at core
Conductor surrounded by insulation
Aluminum sleeve wrapped around insulation
PVC or Teflon jacket covers aluminum sleeve
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10Base5 (3)
10BASE5 vampire tap MAU transceiver
Source: Wikimedia
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10Base2
 Maximum speed 10Mbps
 Wire up to 185 meters (almost 200)
 Used for baseband data transmission
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10Base2 (2)
 Attached to bayonet
connector (BNC)
 BNC connected to Tconnector
 Middle of T-connector
attached to NIC
 Terminator may be
attached to one end of Tconnector
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Twisted Pair Cables
 Contains pairs of insulated copper
wires
 Outer insulating jacket covers wires
 Communication specific properties
 Copper wires twisted to reduce EMI and
RFI
 Length: up to 100 meters
 Transmission speed: up to 10 Gbps
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Twisted Pair Cables (2)
 RJ-45 plug-in connector attaches cable to
device
 Less expensive and
 more flexible than T-connectors
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Twisted Pair Cables (3)
 Two Types
 Shielded (STP)
 Unshielded (UTP)
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Shielded Twisted Pair (STP)
 Surrounded by braided or corrugated
shielding
 Shield reduces interference (EMI, RFI)
 Interval of twists in each pair should differ
 Connectors, wall outlets should be shielded
 Have proper grounding
 Used in strong interference environment
 Expensive cable and equipment
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Unshielded Twisted Pair (UTP)
 Consists of wire pairs within insulated
outer covering
 No shield between wires and
encasement
 Most frequently used network cable
 Reducing EMI and RFI
 Twist interior strands (like STP)
 Build media filter into network equipment
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Unshielded Twisted Pair (UTP)(2)
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Unshielded Twisted Pair (UTP)(3)
 Fewer points of failure
 Has no shield that can tear (up
through Category 5e)
 Connectors and wall outlets do not
need shielding
 Proper grounding not as critical to
purity of signal
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Fiber-Optic Cables
 Glass or plastic fiber cores encased in glass tube
(cladding)
 Fiber cores and cladding are surrounded by PVC
cover
 Signal transmissions consist light (usually infrared)
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Fiber-Optic Cables (2)
 Advantages
 Transmission speeds from 100 Mbps to
over 100 Gbps
 No EMI or RFI problems
 Data travels by light pulse
 Low attenuation
 Secure from unauthorized taps
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Fiber-Optic Cables (3)
 Disadvantages
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Fragile
Expensive
Requires specialized training to install
Cannot be used for analog
communications
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Fiber-Optic Cables (4)
 Single-mode
 Used for long-distance communication
 8-10/125 µm cable transmits one wave at a time
 Communications signal is laser light
 Multimode
 Supports multiple waves (broadband)
 Comes in two varieties
 step index
 graded index
 Cable diameter between 50 and 115 microns
 Source for multimode cable is LED
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Fiber-Optic Cables (5)
 Connector types
 Subscriber
Connector (SC)
 Straight Tip (ST)
 And others…
Source: Wikimedia
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Activity 1-6: Viewing Network Links in
Windows
 Time Required : 5–10 minutes
 Objective: View the Windows Server
2003 and Windows XP LAN and WAN
connection options.
 Description: View the logical links
between various types of networks—
including dial-up and VPNs—joined
through Windows Server 2003 and
Windows XP Professional.
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Activity 1-7: Determining Network
Connectivity in UNIX/Linux
 Time Required: 5 minutes
 Objective: Viewing LAN and WAN
connectivity in UNIX/Linux.
 Description: View network connectivity in
Fedora or Red Hat Enterprise Linux, which
is already configured with the X Window
GNOME interface.
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Activity 2-3: Viewing a NIC’s Physical
Address
 Time Required: 5–10 minutes
 Objective: Determine the physical address of the
NIC in a computer.
 Description: Provides an opportunity to determine
the physical address of a network interface card
(NIC) in a computer. You need access to a computer
that is connected to a network and that runs
Windows XP, Windows Server 2003, Fedora, or Red
Hat Enterprise Linux. For Fedora or Red Hat
Enterprise Linux, you need to use the root account.
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Activity 2-6: Viewing Network Objects
Using the Windows Redirector
 Time Required: 5–10 minutes
 Objective: Use the Microsoft Windows redirector.
 Description: The Microsoft Windows redirector is one
example of the Application layer (Layer 7) at work. In
this activity, you view computers, shared folders, and
shared printers through a Microsoft-based network,
which are made accessible, in part, through the
redirector. Your network needs to have at least one
workgroup (or domain) of computers, shared folders,
and shared printers to fully view the work of the
redirector.
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Activity 4-1: Comparing Different Cable
Types
 Time Required: Approximately 10 minutes
 Objective: Compare coax, twisted-pair, and fiberoptic cable.
 Description: You will better understand your
network if you understand the physical differences
among cable types. You will also be better able to
design a new network or upgrade a legacy network.
In this activity, you compare the flexibility and
appearance of coaxial, twisted-pair, and fiber-optic
cable.
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Activity 4-2: Comparing Cable Connectors
 Time Required: Approximately 10
minutes
 Objective: Compare connectors for
different cable types.
 Description: Each type of cable uses
different kinds of connectors. This
activity enables you to see the kinds of
connectors used for different cable
mediums.
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Activity 4-4: Building a UTP
Cable
 Time Required: Approximately 20–30
minutes
 Objective: Experience building a UTP
cable.
 Description: In this activity, you attach 4pair UTP cable to an RJ-45 connector. You
need the cable, a crimper, a connector, and
a wire stripper. These instructions and
Figure 4-6 follow the EIA/TIA-568-B
standard.
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Homework
 Activities
 Chapter 1: 1-8
 Chapter 2: 2-1
 Problems
 Chapter 2: 1,2,4,8,9,11,14,15,16,17
 Chapter 4:
1,2,6,8,9,10,11,12,13,14,15,16,18,20
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