Network Configuration Basics

Network Configuration Basics

• Networks have common components, functions, and features
• Common network components:
  • Servers: Provide shared resources
  • Clients: Access shared network resources from servers
  • Media: Wires for physical connections
  • Shared data: Files from servers for clients
  • Shared peripherals: Additional resources servers provide
  • Resources: Services or devices available on the network
• Networks are divided into peer-to-peer and server-based categories, with each type having different capabilities
• The network type implemented depends on factors like organization size, required security level, administrative support, and user needs

Peer-to-Peer Networks

• Peer-to-peer networks lack dedicated servers
• There is no hierarchy among computers
• All computers are equal as "peers"
• Each computer acts as both a client and a server
• No administrator is responsible for the entire network
• Users decide what data to share from their computers
• Peer-to-peer networks are also called "workgroups"
• The term "workgroup" implies a small group
• Peer-to-peer networks typically have 10 or fewer computers
• Peer-to-peer networks are relatively simple
• Peer-to-peer networks don't require a central server
• Peer-to-peer networks are less expensive than server-based networks
• Networking software in a peer-to-peer setup doesn't need a uniform performance or security standard
• Peer-to-peer networking is built into different operating systems
• Peer-to-peer implementation advantages:
  • Computers are at users' desks
  • Users act as their own administrators
  • The network employs a simple cabling system

When Peer-to-Peer Is Appropriate

• There are 10 or fewer users
• Users share files and printers, but no specialized servers exist
• Security is not a major concern
• The organization anticipates limited growth

Peer-to-Peer Network Considerations

• Considerations are addressed during network planning
• Network administration tasks include:
  • Managing users and security
  • Making resources available
  • Maintaining data and applications
  • Installing or upgrading application and operating system software
• No system manager oversees the entire network
• Individual users administer their own computers
• Users can share resources as they want
• All peer-to-peer network users define their own security
• Shared resources reside on any computer

Server-Based Networks

• Peer-to-peer setup with dedicated servers needed in environments with more than 10 users
• Most networks have dedicated servers
• Dedicated server functions only as a server, non client/workstation

Specialized Servers

• File Servers: Allow network users to share files.
• File services store, retrieve, and move data across a network
• Users can exchange, read, write, and manage shared files with network file services
• Print Servers: Networks enable new levels of printing
• Users can share printers
• Printers can be placed where convenient
• Workstation performance is improved via data transfer
• Print services manage network printing by allowing simultaneous access
• Database Servers: Provide database services
• Most database systems are client-server based
• The client-side runs on the client, handling data requests
• The server-side handles database operations
• Database servers manage the database and process queries
• Application Servers: Servers store vast amounts of retrievable data
• differs from file servers because applications download data and files upon request
• Application servers keep the database resident and only requests are downloaded
• Client-side applications access data
• Example: employee database for November birthdays
• Mail Servers: Separate server and client applications are used
• Data is selectively downloaded from the server to the client
• Web Servers: Store various web pages
• Proxy Server: Implements network security and provides internet connectivity to all clients
• Proxy servers used as web cache servers improve network response time and efficiency

Server-Based Networks Advantages

• A server-based set up designed to provide and maintains performance and security
• Server-based data sharing can be centrally administered and controlled
• Security is a primary reason to choose server-based networking
• One administrator can manage security for every user on the network through policy application
• Backups can be scheduled, based on importance
• Backups can be scheduled to take place automatically
• Redundancy systems can duplicate data on any server
• A server-based setup can support thousands of users

Network Type Comparisons

• Peer-to-Peer Network:
  • Good for 10 or fewer computers
  • Security established by the user of each computer
  • Individual users administer own computers
• Server-Based Network:
  • Limited only by server and network hardware
  • Extensive and Consistent Resource/User Security
  • Centralized network control requiring at least one knowledgeable administrator

Network Media

• Many cable types are available
• Three Major cabling groups connect the majority of networks:
  • Twisted-pair cable
  • Coaxial cable
  • Fiber-optic cable

Twisted-Pair Cable

• Strands of insulated copper wire twisted
• Two types
  • Unshielded Twisted-Pair (UTP) cables
  • Shielded Twisted-Pair (STP) cables

UTP Cable

• The most popular kind of Twisted-Pair cable
• Becoming the most popular LAN cable
• Maximum length segment is 100 meters
• UTP specifications dictate the number of twists allowed per foot of cable
• The number of twists is determined by the use case
• There are seven standard UTP categories
  • Category 1: Traditional UTP telephone cable for voice
  • Category 2: UTP cable for data transmissions up to 4 Mbps
  • Category 3: UTP cable for data transmissions up to 16 Mbps
  • Category 4: UTP cable for data transmissions up to 20 Mbps
  • Category 5: UTP cable for data transmissions up to 100 Mbps
  • Category 5e: improved version of cat 5 category with 1000MBPS bandwidth
  • Category 6: Physical separator between the four pairs reduces electromagnetic interference
• Susceptible to crosstalk
• Greater number of twists effective in protection against crosstalk

Crosstalk

• When signals from one line bleed into another

UTP Cable Advantages

• Familiar Technology
• Relatively inexpensive and easy to install
• Most LAN systems are readily capable of running over UTP.

UTP Cable Disadvantages

• Sensitive to external electromagnetic interference
• Sensitive to crosstalk
• Sensitive to Attenuation

Attenuation

• A loss of energy.

STP Cable

• Uses a wounded copper-braid jacket of higher quality
• Provides better performance than UTP with high noise or electrical signal

STP Cable Advantage

• Provides better performance than UTP with high noise or electrical signal environments

STP Cable Disadvantages

• It is more labor-intensive than UTP to install
• Not all LAN systems work readily over STP.

Twisted-Pair Cabling Components

• Connection hardware: Twisted-pair cabling uses RJ-45 telephone connectors to connect to a computer
• Distribution racks and rack shelves: Good connections for organizing a network
• Expandable patch panels: Transmission speeds of up to 100 Mbps

Coaxial Cable

• Consists of a core of copper wire surrounded by insulation, a braided metal shielding, and an outer cover
• The core carries electronic signals
• A dielectric insulating layer surrounds the core
• Braided wire mesh acts as a ground against noise and crosstalk
• A non-conducting outer shield made of rubber, Teflon, or plastic surrounds the entire cable
• Resistant to interference/attenuation

Coaxial Cable Types

• Two Types
  • Thin (thinnet) cable
  • Thick (thicknet) cable
• Thinnet Cable:
  • Flexible coaxial cable approximately 0.64 centimeters thick
  • Carries signal for up to 185 meters before signals suffer from attenuation
• Thicknet Cable
  • Rigid coaxial cable 1.27 centimeters in diameter
  • Carries signal for up to 500 meters

Coaxial Cable Connection Hardware

• The BNC cable connector: Soldered or crimped to the end of a cable
• The BNC T connector: Joins the network interface card (NIC) in the computer to the network cable
• The BNC barrel connector: Joins two lines of thinnet to make one longer length
• The BNC terminator: it closes each end of the bus cable to absorb stray signals, or network activity will stop.

Coaxial Cable Advantages

• Less susceptible to interference than twisted-pair cabling.
• Can transmit data for greater distances
• Can transmit voice, video, and data
• Offers familiar technology with reasonable data security.

Coaxial Cable Disadvantages

• Many types of coaxial cables exist
• Suited for one or a few LAN systems
• High metallic content makes it more expensive

Fiber-Optic Cable

• Contains glass or plastic fibers instead of copper wires
• Signals are transmitted across these fibers in the form of light pulses rather than electrical pulses
• Thin filaments of glass consisting of an inner core and an outer cladding
• Single-mode optical fiber has a core diameter of approximately 8.5 µm
• Multimode optical fiber has a core diameter of 62.5 µm

Optical Fiber Advantages

• Greater bandwidth than twisted-pair or coaxial cable
• Optical signals encounter less loss than electrical signals
• Lower attenuation, and higher bandwidth, than copper cabling
• Resists electromagnetic interference, since the signal is light and not electricity

Optical Fiber Disadvantages

• Conversion of light to electricity requires expensive electronics
• Requires specialized installation procedures