Elements of a Local Area Network

1
Elements of a Local Area Network
Printer
9
Client PC (Workstation)
Server
1
Cabling System
7
Connection to other LANs
11
To other LANs
Hub
Local OS NIC Drivers NOS
Applications
8
2
3
4
Internetworking devices
12
5
10
6
Other users
2
Elements of a Local Area Network

• Workstation Laptop or desktop computers
• Local Operating System (LOS) MS-DOS, Windows,
  UNIX, Linux
• NICs (Network Interface Cards) Ethernet, Token
  Ring, FDDI, ATM
• NIC Drivers Software for NIC
• NOS (Network Operating System) Window 2000,
  Novell Netware, TCP/I
• Network Applications File transfer, E-mail
• Cabling System Category 5 UTP. Fiber optic,
  coaxial

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Elements of a Local Area Network

• Connectivity devices (Hub, repeaters,
  concentrators) 10Base T repeater, token ring MAU
• Servers file, print, application, communication
• Other users Peers
• Connection to other LANs Backbone connection to
  internetworking device
• Internetworking devices Bridge, router, switch,
  gateway
• Network management Documentation, protocol
  analyzers

4
Workstation requirements

• Workstation
• 128 MB or more of RAM
• 1 GB or more of hard drive space
• Add network interface card (NIC)
• With Win95, Win98, Win NT, or Win 2000
• A NOS, such as TCP/IP, Novell NetWare, Windows NT
• Other hardware devices
• Networking applications Web browsers, e-mail
  clients

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Network Interface Cards

• The NIC builds, sends, accepts, and process
  frames from the LAN
• Each device connected to a LAN needs a NIC
  installed
• Each NIC has a unique MAC address, which is
  typically burned into the card
• The NIC needs to be the same type as the LAN
• The NIC requires drivers to operate

6
Network Interface Cards
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NIC Drivers

• Software programs that provides a standard
  interface between the NOS and the NIC
• Each NIC driver manages a specific NIC type and
  interfaces
• Common NIC drivers
• NDIS (Network Driver Interfaces) by Microsoft and
  3COM
• ODI (Open Data Link Interface) by Novell and
  Apple
• Clarkson Drivers by academics
• ASI (Adapter Support Interface) by IBM for token
  ring

8
Network Cabling Systems

• ANSI/TIA/EIA Telecommunication Wiring Standards
  568
• A generic specification for installation wires
• Horizontal wiring
• Cabling used to connect individual users and
  devices
• Category 5 UTP (unshielded twisted pair)
• Vertical cabling
• Cabling used to connect networking devices such
  as hubs through the building to internetworking
  device such as router
• Fiber optic cable

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Network Cabling Systems
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Category 5 UTP Horizontal Cabling

• UTP cables are categorized based on their ability
  to carry frequencies

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Category 5 UTP Horizontal Cabling
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Category 5 UTP Installation
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Characteristics of a Cat 5 UTP Cabling System

• Support todays LANs as well as tomorrows
  high-speed networks
• Cat 5 UTP cable consists of four pairs
• Cat 5 termination components (patch panels and
  wall jacks) are required
• RJ45 connectors are used for easy connections
• Two termination locations one in the
  Telecommunications Closet (TC) and one in the
  end-user location
• Support distances of 100 meters
• Well documented cabling system

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Fiber Optic Cable
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Fiber Optic Cable

• Two main types are fiber optic cable
• Advantages
• Distance between repeats (2,000 meters to 5
  miles)
• High bandwidth capabilities
• More secure communication media

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Fiber Optic Backbone Cabling
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Connectivity Devices

• Hubs, Concentrators, and repeaters
• Electronics used to connect nodes together on a
  LAN Hubs
• Hubs vary in sizes and features
• Small stand-alone (6 to 24 ports)
• Medium-sized (up to 60 ports)
• Large chassis design (up to 360 ports)
• Some hubs include support for network management
• Some hubs have internetworking capabilities

18
Bridges

• An internetworking device used to connect
  networks at the data link layer (OSI layer 2)

19
Bridges

• A bridge keeps a lookup table for stations
  connected to its ports
• Examine frames
• places the source MAC address in the lookup table
• Functions
• Filters frames intended for a device on the same
  port the frame came from
• Forwards frames intended for a device on a port
  other than the one it came from
• Always forwards broadcasts frames (FF FF FF FF FF
  FF) for each port

20
Bridges

• Advantages
• Connects various topologies (Ethernet, token
  ring, WAN)
• Easy to install
• Higher layer protocol independent (TCP/IP,
  Novell, Window NT)
• Disadvantages
• Does not make intelligent forwarding decisions
• Can be connected into loops and create broadcast
  storms
• Can cause significant delay in network traffic

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Switches
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Switches

• An internetworking device used to connect
  networks at the data link layer
• An intelligent internetworking device uses its
  lookup tables to make a smart forwarding decision
• Can be very high speed (10 Gbps)
• A switch can speed up a sluggish Ethernet network
  (more to come later)
• Easy to install
• Multiple frames can pass through at the same time

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Routers

• An internetworking device used to connect
  networks together at the network layer (OSI layer
  3)
• The Internet is a network that consists of many
  networks connected with routers
• Transmit IP and IPX protocol traffic through
  connected network (more to come later)
• Use routing protocols such as RIP (Routing
  Information Protocol) and OSPF (Open Shortest
  Path First) to learn connecting routers (more to
  come later)

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Network Operating Systems

• Software that allows computers to communicate
  over a network
• Novell NetWare
• Microsoft Windows NT, Windows 2000
• Banyan VINES
• AppleShare
• Macintosh System 7
• Compaq OpenVMS
• UNIX
• IBM LAN Server
• Sun NFS

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Network Documentation
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Network Documentation

• Maps of the network
• User profile
• Device location
• Device specifications
• MAC address
• IP address
• Cable run information (run number, patch panel
  port)
• Hub information (port, segment)
• Security
• Configuration specifications (router, users,
  server)

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Protocol Analyzers
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LAN Baselining

• A process where networking professionals monitor
  a network in order to know the characteristics of
  the network traffic
• Protocol analyzer platform
• Attach a protocol analyzer to a network to obtain
  statistics such as network utilization (top
  talkers), errors (trend), etc.
• SNMP management system (simple network management
  protocol)
• Management protocol of TCP/IP
• Allows a management station to get access to
  agents in the field (hubs, switches, routers, ..)