ite pc v40_chapter8
Post on 23-Jan-2015
321 Views
Preview:
DESCRIPTION
TRANSCRIPT
© 2007 Cisco Systems, Inc. All rights reserved. Cisco PublicITE PC v4.0 Chapter 8 1
Chapter 8: Networks
IT Essentials: PC Hardware and Software v4.0
ITE PC v4.0 Chapter 8 2© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Purpose of this Presentation
List of chapter objectives
Overview of the chapter contents, including student worksheets
student activities
student labs
Reflection/Activities for instructors to complete to prepare to teach
Additional resources
To provide to instructors an overview of Chapter 8:
ITE PC v4.0 Chapter 8 3© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Chapter 8 Objectives 8.1 Explain the principles of networking
8.2 Describe types of networks
8.3 Describe basic networking concepts and technologies
8.4 Describe the physical components of a network
8.5 Describe LAN topologies and architectures
8.6 Identify standards organizations
8.7 Identify Ethernet standards
8.8 Explain OSI and TCP/IP data models
8.9 Describe how to configure a NIC and a modem
8.10 Identify names, purposes, and characteristics of other technologies used to establish connectivity
8.11 Identify and apply common preventive maintenance techniques used for networks
8.12 Troubleshoot a network
ITE PC v4.0 Chapter 8 4© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Chapter 8 Worksheets, Activities, and Labs 8.1.2 Activity: Advantages and Disadvantages of Networking
8.2.3 Activity: Network Types
8.3.2 Worksheet: Identify IP Address Classes
8.3.4 Activity: Network Protocols
8.8.3 Activity: OSI Model
8.9.1 Worksheet: Internet Search for NIC Drivers
8.9.2 Lab: Configure an Ethernet NIC to use DHCP
8.10.3 Worksheet: Answer Broadband Questions
8.12.2 Worksheet: Diagnose a Network Problem
ITE PC v4.0 Chapter 8 5© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Introduction Chapter 8 is an overview of network principles,
standards, and purposes
It covers the following types of networks:Local Area Network (LAN)
Wide Area Network (WAN)
Wireless LAN (WLAN)
These topics are covered:Network topologies, protocols, and logical models
Hardware needed to create a network
Configuration, troubleshooting, and preventive maintenance
Network software, communication methods, and hardware relationships
ITE PC v4.0 Chapter 8 6© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Networks are systems that are formed by links. People use different types of networks every day:
Mail delivery system
Telephone system
Public transportation system
Corporate computer network
The Internet
Computers can be linked by networks to share data and resources.
A network can be as simple as two computers connected by a single cable or as complex as hundreds of computers connected to devices that control the flow of information.
Principles of Networking
ITE PC v4.0 Chapter 8 7© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Computer Networks Network devices include:
Desktop and laptop computers
Printers and scanners
PDAs and Smartphones
File and print servers
Resources shared across networks include:
Services, such as printing or scanning
Storage devices, such as hard drives or optical drives
Applications, such as databases
Different types of network media:
Copper cabling
Fiber-optic cabling
Wireless connection
ITE PC v4.0 Chapter 8 8© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Benefits of Networking
Fewer peripherals needed
Increased communication capabilities
Avoid file duplication and corruption
Lower cost licensing
Centralized administration
Conserve resources
ITE PC v4.0 Chapter 8 9© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Types of NetworksA computer network is identified by:
The type of media used to connect the devices
The type of networking devices used
How the resources are managed
How the network is organized
How the data is stored
The area it serves
ITE PC v4.0 Chapter 8 10© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Local Area Network (LAN)
A group of interconnected computers that is under the same administrative control.
Can be as small as a single local network installed in a home or small office.
Can consist of interconnected local networks consisting of many hundreds of hosts, installed in multiple buildings and locations.
ITE PC v4.0 Chapter 8 11© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Wide Area Network (WAN) A WAN connects LANs in geographically separated
locations.
A WAN covers a much larger area than a LAN.
The Internet is a large WAN.
Telecommunications service providers (TSP) are used to interconnect these LANs at different locations.
ITE PC v4.0 Chapter 8 12© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Wireless LAN (WLAN) Wireless devices are used to transmit and receive
data using radio waves.
Wireless devices connect to access points within a specified area.
Access points connect to the network using copper cabling.
WLAN coverage can be limited to the area of a room, or can have greater range.
You can share resources such as files and printers, and access the Internet on a WLAN.
ITE PC v4.0 Chapter 8 13© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Peer-to-Peer Networking Share files, send messages, and print to a shared printer.
Each computer has similar capabilities and responsibilities.
Each user decides which data and devices to share.
No central point of control in the network.
Best if there are ten or fewer computers.
ITE PC v4.0 Chapter 8 14© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Disadvantages of Peer-to-Peer Without centralized network administration, it is difficult
to determine who controls network resources.
Without centralized security, each computer must use separate security measures for data protection.
More complex and difficult to manage as the number of computers on the network increases.
Without centralized data storage, data backups must be performed by users.
ITE PC v4.0 Chapter 8 15© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Client/Server Network Client/server network model provides security and
control for the network.
Client requests information or services from the server.
Server provides the requested information or service.
Servers are maintained by network administrators.
Data backups and security measures
Control of user access to network resources
Centralized storage and services include:
Data stored on a centralized file server
Shared printers managed by a print server
Users have proper permissions to access data or printers
ITE PC v4.0 Chapter 8 16© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Networking Concepts and Technologies A computer technician is required to configure and
troubleshoot computers on a network.
A computer technician should understand IP addressing, protocols, and other network concepts.
ITE PC v4.0 Chapter 8 17© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Bandwidth amount of data that can
be transmitted within a fixed time period
measured in bits per second and is usually denoted by the following:
bps - bits per second
Kbps - kilobits per second
Mbps - megabits per second
ITE PC v4.0 Chapter 8 18© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Three Modes of TransmissionData is transmitted in one of three modes:
1. Simplex (Unidirectional transmission) is a single, one-way transmission.
Example: The signal sent from a TV station to your TV.
2. Half-duplex allows data to flow in one direction at a time.
Simultaneous transmission in two directions is not allowed.
Example: Two-way radios, police or emergency mobile radios
3. Full-duplex allows data to flow in both directions at the same time.
Bandwidth is measured in only one direction. 100 Mbps full-duplex means a bandwidth of 100 Mbps in each direction.
Broadband technologies, such as digital subscriber line (DSL) and cable, operate in full-duplex mode.
ITE PC v4.0 Chapter 8 19© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
IP Address An IP address is a unique number that is used to identify a
network device.
An IP address is represented as a 32-bit binary number, divided into four octets (groups of eight bits):
Example: 10111110.01100100.00000101.00110110
An IP address is also represented in a dotted decimal format.
Example: 190.100.5.54
When a host is configured with an IP address, it is entered as a dotted decimal number, such as 192.168.1.5.
Unique IP addresses on a network ensure that data can be sent to and received from the correct network device.
ITE PC v4.0 Chapter 8 20© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
IP Address Classes Class A
Large networks, implemented by large companies and some countries
Class B
Medium-sized networks, implemented by universities
Class C
Small networks, implemented by ISP for customer subscriptions
Class D
Special use for multicasting
Class E
Used for experimental testing
ITE PC v4.0 Chapter 8 21© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Subnet Masks Used to indicate the network portion of an IP address
Is a dotted decimal number
Usually, all hosts within a broadcast domain of a LAN (bounded by routers) use the same subnet mask.
The default subnet masks for three classes of IP addresses:
255.0.0.0 is the subnet mask for Class A
255.255.0.0 is the subnet mask for Class B
255.255.255.0 is the subnet mask for Class C
If an organization owns one Class B network but needs to provide IP addresses for four LANs, the organization will subdivide the Class B network into four smaller parts by using subnetting, which is a logical division of a network. The subnet mask specifies how it is subdivided.
ITE PC v4.0 Chapter 8 22© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
IP Address Configuration Manual configuration
Manually configure each device with the proper IP address and subnet mask.
Dynamic configuration
A Dynamic Host Configuration Protocol (DHCP) server automatically assigns IP addresses to network hosts.
Network Interface Card (NIC) is the hardware that enables a computer to connect to a network and it has two addresses:
The IP address is a logical address that can be changed.
The Media Access Control (MAC) address is "burned-in" or permanently programmed into the NIC when manufactured. The MAC address cannot be changed.
ITE PC v4.0 Chapter 8 23© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Dynamic Host Configuration Protocol (DHCP)
DHCP automatically provides computers with an IP address.
The DHCP server can assign these to hosts:
IP address
Subnet mask
Default gateway
Domain Name System (DNS) server address
ITE PC v4.0 Chapter 8 24© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
DHCP Process and AdvantagesDHCP process:
1. DHCP server receives a request from a host.
2. Server selects IP address information from a database.
3. Server offers the addresses to requesting host.
4. If the host accepts the offer, the server leases the IP address for a specific period of time.
Advantages of DHCP: Simplifies the administration of a network
Reduces the possibility of assigning duplicate or invalid addresses
ITE PC v4.0 Chapter 8 25© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Configure Host to Use DHCPConfigure the host to "Obtain an IP address automatically"
in the TCP/IP properties of the NIC configuration window
ITE PC v4.0 Chapter 8 26© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Internet Protocols A protocol is a set of rules.
Internet protocols are sets of rules governing communication within and between computers on a network.
Many protocols consist of a suite (or group) of protocols stacked in layers. These layers depend on the operation of the other layers in the suite to function properly.
The main functions of protocols:
Identifying errors
Compressing the data
Deciding how data is to be sent
Addressing data
Deciding how to announce sent and received data
ITE PC v4.0 Chapter 8 27© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Common Network Protocols Protocols used for browsing the web, sending and receiving
e-mail, and transferring data files
DescriptionTCP/IP A protocol used to transport data on the Internet.
NETBEUI NETBIOS
A small, fast protocol designed for a workgroup network that requires no connection to the Internet.
IPX and SPX
A protocol used to transport data on a Novell Netware network.
HTTP and HTTPS
A protocol that defines how files are exchanged on the Web.
FTP A protocol that provides services for file transfer and manipulation.
SSH A protocol that is used to connect computers together securely.
Telnet A protocol that uses a text-based connection to a remote computer.
POP A protocol used to download email messages from an email server.
IMAP A protocol used to download email messages from an email server.
SMTP A protocol used to send mail in a TCP/IP network.
ITE PC v4.0 Chapter 8 28© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Internet Control Message Protocol (ICMP) Internet Control Message Protocol (ICMP) is used by
devices on a network to send control and error messages to computers and servers.
PING (Packet Internet Groper) is a simple command line utility used to test connections between computers
Used to determine whether a specific IP address is accessible.
Used with either the hostname or the IP address.
Works by sending an ICMP echo request to a destination computer.
Receiving device sends back an ICMP echo reply message.
ITE PC v4.0 Chapter 8 29© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Ping Command Switches
These command line switches (options) can be used with the ping command.
ITE PC v4.0 Chapter 8 30© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Output of the Ping Command Four ICMP echo requests (pings) are sent to the
destination computer to determine the reliability and reachability of the destination computer.
ITE PC v4.0 Chapter 8 31© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Physical Network Components
Network devices:
Computers
Hubs
Switches
Routers
Wireless access points
Network media:
Twisted-pair copper cabling
Fiber-optic cabling
Radio waves
ITE PC v4.0 Chapter 8 32© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Hubs
Extend the range of a signal by receiving then regenerating it and sending it out all other ports
Traffic is sent out all ports of the hub
Allow a lot of collisions on the network segment and are often not a good solution
Also called concentrators because they serve as a central connection point for a LAN
ITE PC v4.0 Chapter 8 33© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Bridges and Switches A packet, along with its MAC address information, is
called a frame.
LANs are often divided into sections called segments bounded by bridges.
A bridge has the intelligence to determine if an incoming frame is to be sent to a different segment, or dropped. A bridge has two ports.
A switch (multiport bridge) has several ports and refers to a table of MAC addresses to determine which port to use to forward the frame.
ITE PC v4.0 Chapter 8 34© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Routers
Routers are devices that connect entire networks to each other.
Use IP addresses to forward packets to other networks.
Can be a computer with special network software installed.
Can be a device built by network equipment manufacturers.
Contain tables of IP addresses along with optimal routes to other networks.
ITE PC v4.0 Chapter 8 35© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Wireless Access Points
Provide network access to wireless devices such as laptops and PDAs.
Use radio waves to communicate with radios in computers, PDAs, and other wireless access points.
Have limited range of coverage.
ITE PC v4.0 Chapter 8 36© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Multipurpose Devices Perform more than one function.
More convenient to purchase and configure just one device.
Combines the functions of a switch, a router and a wireless access point into one device.
The Linksys 300N is an example of a multipurpose device.
ITE PC v4.0 Chapter 8 37© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Twisted-Pair Cabling A pair of twisted wires forms a circuit that transmits data.
The twisted wires provide protection against crosstalk (electrical noise) because of the cancellation effect.
Pairs of copper wires are encased in color-coded plastic insulation and twisted together.
An outer jacket, called poly-vinyl chloride (PVC), protects the bundles of twisted pairs.
ITE PC v4.0 Chapter 8 38© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Two Basic Types of Twisted-Pair Cables Unshielded twisted-pair (UTP)
Has two or four pairs of wires
Relies on the cancellation effect for reduction of interference caused by electromagnetic interface (EMI) and radio frequency interference (RFI)
Most commonly used cabling in networks
Has a range of 328 ft (100 meters)
Shielded twisted-pair (STP)
Each pair is wrapped in metallic foil to better shield the wires from electrical noise and then the four pairs of wires are then wrapped in an overall metallic braid or foil.
Reduces electrical noise from within the cable.
Reduces EMI and RFI from outside the cable.
ITE PC v4.0 Chapter 8 39© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Category Rating UTP comes in several categories that are based on two
factors:
The number of wires in the cable
The number of twists in those wires
Category 3 is used for telephone connections.
Category 5 and Category 5e have are the most common network cables used.
Category 6 cable has higher data rate than the Cat 5 cables.
ITE PC v4.0 Chapter 8 40© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Coaxial Cable A copper-cored network cable surrounded by a heavy
shielding
Types of coaxial cable:
Thicknet or 10Base5 - Coax cable that was used in networks and operated at 10 megabits per second with a maximum length of 500 m
Thinnet or 10Base2 - Coax cable that was used in networks and operated at 10 megabits per second with a maximum length of 185 m
RG-59 - Most commonly used for cable television in the US
RG-6 - Higher quality cable than RG-59 with more bandwidth and less susceptibility to interference
ITE PC v4.0 Chapter 8 41© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Fiber-Optic Cable A glass or plastic strand that transmits
information using light and is made up of one or more optical fibers enclosed together in a sheath or jacket.
Not affected by electromagnetic or radio frequency interference.
Signals are clearer, can go farther, and have greater bandwidth than with copper cable.
Usually more expensive than copper cabling and the connectors are more costly and harder to assemble.
Two types of glass fiber-optic cable:
Multimode and Single-mode
ITE PC v4.0 Chapter 8 42© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Two Types of LAN Topologies
Physical topology is the physical layout of the components on the network
Logical topology determines how the hosts access the medium to communicate across the network
ITE PC v4.0 Chapter 8 43© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
LAN Physical TopologiesA physical topology defines the way in which computers,
printers, and other devices are connected to a network.
Bus
Ring
Star
Hierarchical star
Mesh
ITE PC v4.0 Chapter 8 44© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Bus Topology Each computer connects
to a common cable
Cable connects one computer to the next
Ends of the cable have a terminator installed to prevent signal reflections and network errors
Only one computer can transmit data at a time or frames will collide and be destroyed
Bus topology is rarely used today. Possibly suitable for a home office or small business with few hosts
ITE PC v4.0 Chapter 8 45© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Ring Topology Hosts are connected in a physical ring or circle.
The ring has no beginning or end, so the cable does not need to be terminated.
A special frame, a token, travels around the ring, stopping at each host.
The advantage of a ring topology is that there are no collisions.
There are two types of ring topologies:
Single-ring and Dual-ring
ITE PC v4.0 Chapter 8 46© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Star Topology Has a central connection point:
a hub, switch, or router
Hosts connect directly to the central point with a cable
Costs more to implement than the bus topology because more cable is used, and a central device is needed
Easy to troubleshoot, since each host is connected to the central device with its own wire.
ITE PC v4.0 Chapter 8 47© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Hierarchical or Extended Star Topology A star network with an additional networking device
connected to the main networking device to increase the size of the network.
Used for larger networks
ITE PC v4.0 Chapter 8 48© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Mesh Topology Connects all devices to each other
Failure of any cable will not affect the network
Used in WANs that interconnect LANs
Expensive and difficult to install because of the amount of cable needed
The Internet is an example of a mesh topology
Often used by governments when data must be available in the event of a partial network failure
ITE PC v4.0 Chapter 8 49© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Logical TopologiesThe two most common types of logical topologies are
broadcast and token passing.
In a broadcast topology, there is no order that the hosts must follow to use the network – it is first come, first served for transmitting data on the network.
Token passing controls network access by passing an electronic token sequentially to each host. When a host receives the token, it can send data on the network. If the host has no data to send, it passes the token to the next host and the process repeats itself.
ITE PC v4.0 Chapter 8 50© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
LAN Architecture Is the overall structure of a computer or communication
system.
Designed for a specific use and have different speeds and capabilities.
Describes both the physical and logical topologies used in a network.
The three most common LAN architectures:
Ethernet
Token Ring
Fiber-DistributedData Interface (FDDI)
ITE PC v4.0 Chapter 8 51© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Ethernet Based on the IEEE 802.3 standard, which specifies
that a network use the Carrier Sense Multiple Access with the Collision Detection (CSMA/CD) access control method.
Hosts access the network using the first come, first served broadcast topology method to transmit data.
Standard transfer rates
10 Mbps (Ethernet) “10Base-T”
100 Mbps (FastEthernet) “100Base-T”
1000 Mbps = 1 Gbps (Gigabit Ethernet) “1000Base-T”
ITE PC v4.0 Chapter 8 52© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Token Ring Reliable network architecture
Originally developed by IBM
Based on the token-passing access control method
Often integrated with IBM mainframe systems
Used with smaller computers and mainframes
Physically, a star-wired ring because the outer appearance of the network design is a star
Inside the device, wiring forms a circular data path, creating a logical ring
ITE PC v4.0 Chapter 8 53© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Fiber Distributed Data Interface (FDDI) A type of Token Ring network
Often used for LANs, connecting several buildings in an office complex or on a university campus
Runs on fiber-optic cable
High-speed performance combined with token-passing advantage
Runs at 100 Mbps with a primary and secondary ring topology
Normally, traffic flows only on the primary ring and uses a secondary ring is a backup.
FDDI dual ring supports up to 500 computers per ring
ITE PC v4.0 Chapter 8 54© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Standards OrganizationsName Type Standards Established
ITU-TITU Telecommunication Standardization Sector
(formerly CCITT)
one of the three Sectors of the International
Telecommunication Union
Standards covering all fields of
telecommunications
Became ITU-T in 1992
IEEE Institute of Electrical and Electronics Engineers
A non-profit, technical professional association
Standards for the computer and electronics
industry1884
ISOInternational
Organization for Standardization
A network of the national standards institutes of 157
countries
Promote the development of international standards
agreements1947
IAB Internet Architecture Board
A committee; an advisory body
Oversees the technical and engineering
development of the Internet
1979; first named ICCB
IECInternational
Electrotechnical Commission
Global organizationStandards for all
electrical, electronic, and related technologies
1906
ANSI American National Standards Institute
Private, non-profit organization
Seeks to establish consensus among groups
1918
TIA/EIA
Telecommunications Industry Association / Electronic Industries
Alliance
Trade associationsStandards for voice and
data wiring for LANs
After the deregulation of the
U.S. telephone industry in 1984
ITE PC v4.0 Chapter 8 55© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Ethernet StandardsEthernet protocols describe the rules that control how
communication occurs on an Ethernet network.
The 802.2 standard defines how a device addresses other devices on the medium.
The 802.3 standard defines the methodology that devices must use when they use the media.
The 802.11x standards define how wireless devices communicate using radio waves.
ITE PC v4.0 Chapter 8 56© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Cabled Ethernet Standards IEEE 802.3 Ethernet standard specifies that a network implement
the CSMA/CD access control method.
In CSMA/CD operation:
All end stations "listen" to the network wire for clearance to send data.
When the end station detects that no other host is transmitting, the end station will attempt to send data.
If no other station sends any data at the same time, this transmission will arrive at the destination computer successfully.
If another end station transmits at the same time, a collision will occur on the network media.
The first station that detects the collision, sends out a jam signal to tell all stations to stop transmitting and to run a backoff algorithm.
All stations stop transmitting and re-try after a random period of time.
ITE PC v4.0 Chapter 8 57© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
10BASE-T 10BASE-T is an Ethernet technology that uses a star topology.
The ten (10) represents a speed of 10 Mbps.
BASE represents baseband transmission.
The T represents twisted-pair cabling.
Advantages of 10BASE-T:
Installation is inexpensive compared to fiber-optic installation.
Cables are thin, flexible, and easier to install than coaxial cabling.
Equipment and cables are easy to upgrade.
Disadvantages of 10BASE-T:
The maximum length for a 10BASE-T segment is 328 ft (100 m).
Cables are susceptible to Electromagnetic Interference (EMI).
ITE PC v4.0 Chapter 8 58© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
100BASE-TX “FastEthernet” Has a theoretical bandwidth of 100 Mbps.
The "X" indicates different types of copper and fiber-optic can be used.
Advantages of 100BASE-TX:
Transfer rates of 100BASE-TX are ten times that of 10BASE-T
100BASE-X uses twisted-pair, inexpensive and easy to install
Disadvantages of 100BASE-TX:
Maximum length for a 100BASE-TX segment is 329 ft (100 m).
Cables are susceptible to Electromagnetic Interference (EMI).
ITE PC v4.0 Chapter 8 59© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
1000BASE-TX “Gigabit Ethernet” Advantages of 1000BASE-T:
1 Gbps is ten times faster than Fast Ethernet and 100 times faster than Ethernet.
Increased speed makes it possible to implement bandwidth-intensive applications, such as live video.
The 1000BASE-T architecture has interoperability with 10BASE-T and 100BASE-TX.
Disadvantages of 1000BASE-T:
Maximum length for a 1000BASE-T segment is 328 ft (100 m).
It is susceptible to interference.
Gigabit NICs and Switches are expensive.
Additional equipment is required.
ITE PC v4.0 Chapter 8 60© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Wireless Ethernet Standards IEEE 802.11 is the standard that specifies connectivity
for wireless networks.
Wi-Fi (wireless fidelity), refers to the 802.11 family
802.11 (the original specification)
802.11b
802.11a
802.11g
802.11n
These protocols specify the frequencies, speeds, and other capabilities of the different Wi-Fi standards.
ITE PC v4.0 Chapter 8 61© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
IEEE 802.11a WLAN Standard Allows data rates as high as 54 Mbps
Devices operate in the 5 GHz radio frequency range
Avoids some interference issues of 802.11b
802.11a is not backward compatible to 802.11b
Dual mode wireless NICs are available
802.11a has a range of approximately 100 ft (30 m)
ITE PC v4.0 Chapter 8 62© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
IEEE 802.11b WLAN Standard Operates in the 2.4 GHz frequency range
Maximum theoretical data rate of 11 Mbps, but typically about 6.5 Mbps
Average range of approximately 100 ft (30 m) at 11 Mbps and 295 ft (90 m) at 1 Mbps
Range fluctuates depending on the operational speed.
Signal quality dictates the operational speed of 802.11b.
Bluetooth devices, cordless phones, and even microwave ovens operate in the 2.4 GHz band, possibly causing interference.
ITE PC v4.0 Chapter 8 63© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
IEEE 802.11g and 802.11n 802.11g
Allows data rates as high as 54 Mbps
Operates in the same 2.4 GHz spectrum as 802.11b
802.11g is backward compatible with 802.11b
Interoperability among all speeds (a, b, g) exists
Average range of approximately 100 ft (30 m)
802.11n
Has a theoretical bandwidth of 540 Mbps
Operates in either the 2.4 GHz or 5 GHz frequency range
Maximum range of 164 ft (50 m)
Expected approval for 802.11n is April 2008 or earlier
ITE PC v4.0 Chapter 8 64© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Wireless Ethernet StandardsBandwidth Frequency Range Interoperability
802.11a Up to 54 Mbps 5 GHz band100 feet
(30 meters)
Not interoperable with 802.11b, 802.11g, or
802.11n
802.11b Up to 11 Mbps 2.4 GHz band100 feet
(30 meters)Interoperable with
802.11g
802.11g Up to 54 Mbps 2.4 GHz band100 feet
(30 meters)Interoperable with
802.11b
802.11n
(Pre-standard)Up to 540 Mbps 2.4 GHz band
164 feet (50 meters)
Interoperable with 802.11b and 802.11g
802.15.1 Bluetooth
Up to 2 Mbps2.4 GHz band
or 5 GHz band
30 feet (10 meters)
Not interoperable with any other 802.11
ITE PC v4.0 Chapter 8 65© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
OSI and TCP/IP Data Models Architectural model
Separates functions of protocols into manageable layers
Each layer performs a specific function in network communication
TCP/IP model
A four-layer model that explains the TCP/IP suite of protocols
TCP/IP is the dominant standard for transporting data across networks
Open Systems Interconnect (OSI) model
Standards defining how devices communicate on a network
Ensures interoperability between network devices
ITE PC v4.0 Chapter 8 66© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
The TCP/IP Reference Model
Description Protocols
Application Provides network services to user applications
HTTP, HTML, Telnet, FTP, SMTP,
DNS
Transport Provides end-to-end management of data and divides data into segments
TCP, UDP
Internet Provides connectivity between hosts in the network
IP, ICMP, RIP, ARP
Network Access
Describes the standards that hosts use to access the physical media
Frame of reference used to develop the Internet's protocols
Consists of layers that perform functions necessary to prepare data for transmission over a network
ITE PC v4.0 Chapter 8 67© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
The OSI Model The OSI model is an industry standard framework that is
used to divide network communications into seven layers.
Although other models exist, most network vendors today build their products using this framework.
A protocol stack is a system that implements protocol behavior using a series of layers.
Protocol stacks can be implemented either in hardware or software, or in a combination of both.
Typically, only the lower layers are implemented in hardware, and the higher layers are implemented in software.
ITE PC v4.0 Chapter 8 68© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
The OSI ModelLayer Description
Application 7 Responsible for network services to applications
Presentation 6 Transforms data formats to provide a standard interface for the Application layer
Session 5 Establishes, manages and terminates the connections between the local and remote application
Transport 4 Provides reliable transport and flow control across a network
Network 3 Responsible for logical addressing and the domain of routing
Data Link 2 Provides physical addressing and media access procedures
Physical 1 Defines all the electrical and physical specifications for devices
Remember the OSI layers with this mnemonic:
"Please Do Not Throw Sausage Pizza Away"
ITE PC v4.0 Chapter 8 69© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Compare OSI and TCP/IP Models
ITE PC v4.0 Chapter 8 70© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Configuring a NIC and a Modem Install the NIC and the driver.
If necessary, download an updated driver from the manufacturer.
Connect the computer to the network.
Also, you may need to install a modem to connect to the Internet.
NIC
Modem
ITE PC v4.0 Chapter 8 71© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Install or Update a NIC Driver Manufacturers publish new driver software for NICs
May enhance the functionality of the NIC
May be needed for operating system compatibility
Install a new driver
Disable virus protection software
Install only one driver at a time
Close all applications that are running so that they are not using any files associated with the driver update.
Visit the manufacturer's website and download a self-extracting executable driver file that will automatically install or update the driver
ITE PC v4.0 Chapter 8 72© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Install or Update a NIC Driver
Alternatively, you can click the Update Driver button in the toolbar of the Device Manager.
After updating the driver, reboot the computer.
If a new NIC driver does not perform as expected after it has been installed, the driver can be uninstalled, or rolled back, to the previous driver.
ITE PC v4.0 Chapter 8 73© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Attach Computer to Existing Network Plug a network cable into the
network port on the computer.
Plug the other end into the network device or wall jack.
After connecting the network cable, look at the LEDs, or link lights, next to the Ethernet port on the NIC.
If there is no activity, you may have to replace a faulty cable, a faulty hub port, or even a faulty NIC to correct the problem.
ITE PC v4.0 Chapter 8 74© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Configure the NIC The computer will now need an IP address.
If the computer does not acquire an IP address from a DHCP server, you will need to enter a unique IP address in the TCP/IP properties of the NIC.
Click Start > Control Panel > Network Connections > Local Area Connection
Every NIC must be configured with the following information:
The same protocol must be implemented between any two computers that communicate on the same network.
The IP address must be unique to each device and can be configured manually or dynamically.
The MAC address is a unique address assigned by the manufacturer and cannot be changed.
ITE PC v4.0 Chapter 8 75© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
What is the Assigned IP Address?If you do not know your IP address yet, use the ipconfig
program, to find it.
ITE PC v4.0 Chapter 8 76© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Test Connectivity Using Ping Ping your own IP address to make sure your NIC is
working properly.
Ping your default gateway or another computer on your network.
Ping a popular website.
If you cannot ping one of these items, you may need to begin troubleshooting.
ITE PC v4.0 Chapter 8 77© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Modem Installation A modem is an electronic device that transfers data
between one computer and another using analog signals over a telephone line.
A transmitting modem converts digital data to analog signals, called modulation.
The receiving modem reconverts the analog signals back to digital data, called demodulation.
An internal modem plugs into an expansion slot on the motherboard and a software driver is installed.
External modems connect to a computer through the serial and USB ports and also require a software driver.
ITE PC v4.0 Chapter 8 78© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Dial-up Networking (DUN) When computers use the public telephone system to
communicate, it is called dial-up networking (DUN).
Modems communicate with each other using audio tone signals. DUN creates a Point-to-Point Protocol (PPP) connection between two computers over a phone line.
After the line connection has been established, a "handshaking sequence" takes place between the two modems and the computers.
The digital signals from the computers must be converted to an analog signal to travel across telephone lines. They are converted back to the digital form, 1s and 0s, by the receiving modem so that the receiving computer can process the data.
ITE PC v4.0 Chapter 8 79© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
AT Commands
AT (“Attention”) Commands - commands for modems
Most modem software uses the Hayes-compatible command set.
The AT command set is used to issue dial, hang up, reset, and other instructions to the modem.
Most modem user manuals list the AT command set.
The Standard Hayes compatible code to dial is ATDxxxxxxx
Usually no spaces in an AT string.
The "x" signifies the number dialed.
Seven digits for a local call and 11 digits for long-distance.
Function
AT Attention code that precedes all modem action commands
AP Dial the phone number, xxxxxxx, using pulse dialing
ATDT xxxxxxx Dial the phone number, xxxxxxx, using tone dialing
ATA Answer the phone immediately
ATHO Hang up the phone immediately
ATZ Reset the modem to its power up settings
ATF Reset modem parameters and settings to the factory defaults
AT+++ Break the signal, change from data mode to command mode
P Signifies pulse dialing
T Signifies tone dialing
W Indicates that the modem will wait
ITE PC v4.0 Chapter 8 80© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Other Types of Connectivity Phone, cable, satellite, and private telecommunications
companies provide Internet connections.
In the 1990s, low-speed modems used the plain old telephone system (POTS) to send and receive data.
Today, many businesses and home users have switched to high-speed Internet connections, which allows for transmission of data, voice and video.
ITE PC v4.0 Chapter 8 81© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Integrated Services Digital Network (ISDN) A standard for sending voice, video, and data over telephone
wires.
Provides higher-quality voice and higher-speed data transfer than traditional analog telephone service.
Three services offered by ISDN digital connections: Basic Rate Interface (BRI), Primary Rate Interface (PRI), and Broadband ISDN (BISDN).
ISDN uses two different types of communications channels:
"B" channel is used to carry the information - data, voice, or video.
"D" channel is usually used for controlling and signaling, but can be used for data.
ITE PC v4.0 Chapter 8 82© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
ISDN Types
Type Description
BRI
ISDN Basic Rate Interface offers a dedicated 128 Kbps connection using two 64 Kbps B channels. ISDN BRI also uses on 16 Kbps D channel for call setup, control, and teardown.
PRI
ISDN Primary Rate Interface offers up to 1.544 Mbps over 23 B channels in North America and Japan or 2.048 Mbps over 30 B channels in Europe and Australia. ISDN PRI also uses one D channel for call maintenance.
BISDNBroadband ISDN manages different types of service all at the same time. BISDN is mostly used only in network backbones.
ITE PC v4.0 Chapter 8 83© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Digital Subscriber Line (DSL) An "always-on" technology; there is no need to dial up
each time to connect to the Internet.
Uses the existing copper telephone lines to provide high-speed data communication between end users and telephone companies.
Asymmetric DSL (ADSL) is currently the most commonly used DSL technology.
Has a fast downstream speed, typically 1.5 Mbps.
Upload rate of ADSL is slower.
Not the best solution for hosting a web server or FTP server.
ITE PC v4.0 Chapter 8 84© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
DSL TypesType Description
ADSLAsymmetric DSL is most common. Downstream speed from 384 Kbps to 6 Mbps. Upstream speeds lower than downstream speeds.
HDSLHigh Data Rate DSL provides equal bandwidth in both directions.
SDSLSymmetric DSL provides the same speed, up to 3 Mbps, for uploads and downloads
VDSLVery High Data Rate DSL is capable of bandwidths between 13 and 52 Mbps downstream, and 16 Mbps upstream.
IDSLISDN DSL is DSL over ISDN lines. Uses ordinary phone lines. Requires ISDN adapters
ITE PC v4.0 Chapter 8 85© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Power Line Communication (PLC) Uses power distribution wires (local electric grid) to
send and receive data.
May be available in areas without any other service.
Is faster than an analog modem.
May cost less than other high-speed connections.
Will become more common in time.
Can be used in a home or office environment through an electrical outlet.
Can control lighting and appliances.
ITE PC v4.0 Chapter 8 86© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Broadband Connectivity Broadband is a technique used to transmit and receive
multiple signals using multiple frequencies over one cable.
Broadband uses a wide range of frequencies that may be further divided into channels.
Some common broadband network connections include:
Cable
Digital Subscriber Line (DSL)
Integrated Services Digital Network (ISDN)
Satellite
ITE PC v4.0 Chapter 8 87© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Cable Modem A cable modem connects your computer to the cable
company using the same coaxial cable that connects to your cable television.
You can connect the computer directly into the cable modem.
You can connect a router, switch, hub, or multipurpose network device so multiple computers can share the Internet connection.
ITE PC v4.0 Chapter 8 88© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
DSL Modem and Filter Voice and data signals are carried
on different frequencies on the copper telephone wires.
A filter is used to prevent DSL signals from interfering with phone signals. Plug the filter into a phone jack and plug the phone into the filter.
The DSL modem does not need a filter. A DSL modem can connect directly to your computer,or it can be connected to a networking device to sharethe Internet connection between multiple computers.
ITE PC v4.0 Chapter 8 89© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
A Typical ISDN Connection ISDN uses multiple channels and can carry voice,
video, and data; therefore, it is considered a type of broadband.
ITE PC v4.0 Chapter 8 90© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Broadband Satellite
Uses a satellite dish for two-way communication.
Download speeds are typically up to 500 Kbps, while uploads are closer to 56 Kbps.
People in rural areas often use satellite broadband because it is a faster connection than dial-up and no other broadband connection may be available.
ITE PC v4.0 Chapter 8 91© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Is a method used to carry telephone calls over data networks and the Internet.
Converts the analog signals of voices into digital information that is transported in IP packets.
Can also use an existing IP network to provide access to the public switched telephone network (PSTN).
Depends on a reliable Internet connection. When a service interruption occurs the user cannot make phone calls.
Voice over IP (VoIP)
ITE PC v4.0 Chapter 8 92© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Preventive Maintenance for Networks Common preventive maintenance techniques should
continually be performed for a network to operate properly. Keep network rooms clean and change air filters often. Checking the various components of a network for wear. Check the condition of network cables because they are often
moved, unplugged, and kicked. Label the cables to save troubleshooting time later. Refer to
wiring diagrams and always follow your company's cable labeling guidelines.
AC power adapters should be checked regularly. The uninterruptible power supply (UPS) should be tested
to ensure that you have power in the case of an outage.
ITE PC v4.0 Chapter 8 93© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Step 1 Gather data from the customer
Step 2 Verify the obvious issues
Step 3 Try quick solutions first
Step 4 Gather data from the computer
Step 5 Evaluate the problem and implement the solution
Step 6 Close with the customer
Troubleshooting Process
ITE PC v4.0 Chapter 8 94© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
1. Gather Data from the Customer Customer information
Company name, contact name, address, phone number
Computer configurationOperating system, protection software, network environment, connection type
Use a work order to collect information
Description of problemOpen-ended questions
What type of network connection is your computer using?
Closed-ended questions
Can you access the Internet?
ITE PC v4.0 Chapter 8 95© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
2. Verify the Obvious IssuesExamine the most obvious causes of a problem.
Check that the network cables are properly connected.
If a cable is not connected properly or if a NIC is improperly installed or configured, the LED link lights on the NIC will not light.
Check the wireless access point signal strength in your network client software.
Use the ipconfig tool to make sure that the computer has a valid, unique IP address. Check for errors in the subnet mask and default gateway address.
ITE PC v4.0 Chapter 8 96© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
3. Try Quick Solutions First Check that all cables are connected to the proper
locations.
Unseat and then reconnect cables and connectors.
Reboot the computer or network device.
Login as a different user.
Repair or re-enable the network connection.
Contact the network administrator.
ITE PC v4.0 Chapter 8 97© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
4. Gather Data from the Computer Ping is used to check network connectivity. It sends a
packet to the specified address and waits for a reply.
Nslookup is used to query Internet domain name server. It returns a list of hosts in a domain or the information for one host.
Tracert is used to determine the route taken by packets when they travel across the network. It shows where communications between your computer and another computer are having difficulty.
Net View is used to display a list of computers in a workgroup. It shows the available shared resources on a network.
ITE PC v4.0 Chapter 8 98© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
You may need to conduct further research
Problem solving experience
Other technicians
Internet search and technical websites
News groups and online forums
Manufacturer FAQs
Computer and device manuals
5. Evaluate Problem & Implement Solution
ITE PC v4.0 Chapter 8 99© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
6. Close with the CustomerWhen you are confident that the problem is resolved: Document the customer information, problem description,
and steps to resolve the issue in the work order.
Explain to the customer how you solved the problem .
Let the customer verify that the problem has been solved.
Complete all documentation including sales orders, time logs, and receipts.
Complete the work order.
Update the repair journal. You can use the notes from the journal for future reference.
ITE PC v4.0 Chapter 8 100© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Common Problems and Solutions
Problem Symptom Possible Solution
Computer is not able to connect to a popular website.
Check DNS settings, hardware and/or software firewall settings.
Computer has an IP address of 169.254.x.x.
Check to make sure the DHCP server is operational and can be pinged.
Computer is not able to connect to the network.
Check for loose network cables.
Computer is not able to print using the network printer.
Check user permissions and status of network printer.
ITE PC v4.0 Chapter 8 101© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Chapter 8 Summary The fundamentals of networking
The benefits of a network
The ways to connect computers to a network
The different aspects of troubleshooting a network
How to analyze problems and implement simple solutions
ITE PC v4.0 Chapter 8 102© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Instructor Training Activities
ITE PC v4.0 Chapter 8 103© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Activities for Instructor Training1. Take the Quiz provided in Chapter 8 course content.
2. Complete the four worksheets, four activities, and the lab included in Chapter 8. Make notes of potential issues and questions that students may have.
3. Conduct Internet research to pre-screen online resources for students to use in completing the student worksheets, 8.9.1 Internet Search for NIC Drivers.
4. Brainstorm a list of at least 4 troubleshooting scenarios to provide students more opportunities to practice this skill.
Refer to the student worksheet, 8.12.2 Diagnose a Network Problem.
ITE PC v4.0 Chapter 8 104© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Instructor Training Discussion Share with the other instructors the list of online
resources found that students might use in completing the research.
Share with the other instructors the list of additional troubleshooting scenarios.
Participate in a role-playing activity of one of the troubleshooting scenarios.
Following the role-playing activity, discuss the different ways you might incorporate role-playing activities into your classroom. Share ideas of how to make the student successful in these activities.
ITE PC v4.0 Chapter 8 105© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Additional Resources Telecommunication Standardization Sector of the International
Telecommunications Union (ITU-T) http://www.itu.int/ITU-T/
Institute of Electrical and Electronics Engineers (IEEE) http://www.ieee.org/
International Organization for Standardization (ISO) http://www.iso.ch/iso/
Internet Architecture Board (IAB) http://www.iab.org/
International Electrotechnical Commission (IEC) http://www.iec.ch/
American National Standards Institute (ANSI) http://www.ansi.org/
Telecommunications Industry Association (TIA) http://www.tiaonline.org/
Electronic Industries Alliance (EIA) http://www.eia.org/
ITE PC v4.0 Chapter 8 106© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
Q and A
ITE PC v4.0 Chapter 8 107© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public
top related