Chapter 6 Local Area Network Hardware

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Chapter 6Local Area Network Hardware

• LAN Technology Architecture
• Network Interface Cards
• Wiring Center
• LAN Switches
• Media

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LAN Technology Architecture

• Shared-media LAN
• Switched LAN

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Shared- Media LAN

• Sharing available bandwidth among all devices
• 100BaseT, 100VG-Any-LAN, isochronous Ethernet

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Switched LAN

• Dedicated (guaranteed) bandwidth to switch
  connected devices (point-to-point)
• Limited number of simultaneous point-to-point
  connections
• Replace the media-sharing LAN for more bandwidth

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Full-Duplex Network Architectures

• Special type of switched LAN
• Full-duplex Ethernet, full-duplex token ring,
  full-duplex FDDI
• Full-duplex Ethernet NICs, full-duplex NIC
  drivers, and full-duplex Ethernet switches

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Network Interface Cards (NICs)Functions

• Physical link between devices
• Pass data between devices
• Determine the network architecture and protocol

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NICs - Technology Analysis

• Bus Type
• ISA, EISA, MCA, NuBus (Apple), PCI, PCMCIA, Sbus
  (Sun)
• Internal/external or external interface to
  parallel port
• Data transfer technique
• Bus-mastering DMA (direct memory access)
• DMA(direct memory access)
• Shared memory
• Program I/O
• Media interfaces (cables connectors)
• Network drivers
• Management tools
• Other hardware requirements
• On-board processor capabilities
• On-board memory
• System memory requirements

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Bus Types

• Industry Standard Architecture (ISA) 8-bit or
  16-bit
• Microchannel Architecture (MCA) 32-bit
• Extended Industry Standard Architecture (EISA)
  8-bit, 16-bit, 32-bit
• Local bus
• Video Electronics Standards Association (VESA
  local bus or VL-Bus)
• Peripheral Component Interconnect (PCI local bus)
• Advanced graphic port by Intel

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NICs - Trends

• Dual-speed cards 10/100 Mbps
• Integrated or on-board NICs
• Multiport NICs
• On-NIC virus protection and security
• Integrated repeater modules (up to seven devices)
• Full-duplex mode
• Performance improvement

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NIC Drivers

• Functions communication between NIC and PCs
  operating system
• Types
• Monolithic drivers
• Multiprotocol network interface card drivers
• NDIS (network driver interface specification) by
  Microsoft 3Com
• ODI (open data-link interface) by Novell Apple
• PCMCIA (PC Card or CardBus) drivers card and
  socket services (CSS)

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PCMCIA

• Personal Computer Memory Card Interface
  Association
• People Cant Master Computer Industry Acronyms

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Wiring Center

• For Shared-media LAN
• Types
• Stand-along hubs
• Stackable hubs
• Multistation access units
• Enterprise hubs

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Stand-along Hubs

• Repeaters
• Retiming regenerating digital signals
• Linking devices or LAN segments of similar
  network architecture
• Hubs
• Subset of repeaters
• Connect single devices to its ports
• Concentrator or intelligent concentrator

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Stackable Hubs

• Cascading ports for hubs
• Specialized hub-to-hub cables
• Expandability and manageability
• Stackability ranging from 4 to 20

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Multistation Access Units

• MAU token ring hub
• Shielded twisted pair with Type 1 connectors
• Eight ports with additional ports RI (ring in)
  RO (ring out) for cascading
• Active-management MAUs with identifying and
  removing malfunctioning token ring adapters

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Enterprise Hubs

• Modular concentrators or network in a box
• Modular design and chassis-based architecture
• Hot-swappable inserting and removing module with
  power on
• Types of modules
• Ethernet, token ring, FDDI port modules
• Management modules security, encryption,
  authorization modules
• Internetworking modules router bridge modules
• Multiple power supplies for redundant power
• Media UTP, STP, thick or thin coax, fiber

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Hub Management

• Software
• Local hub management software
• Enterprise network management software HPs Open
  View, IBMs NetView, Suns SunNet Manager,
  Novells NMS
• Standard protocol
• Simple network management protocol (SNMP)
• Management information bases (MIB)
• Remote monitoring (RMON) MIB

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Wiring Center Analysis

• Expendability
• Reliability
• Network architecture
• Media
• Internetworking WAN, LAN, different types
• Management

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Wiring Center Management

• Operating system
• Faults
• Alarms
• Statistics
• Security
• Remote
• SNMP

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LAN Switches Architectures

• Stand-alone switches or slide-in modules for
  enterprise switches
• Ethernet switches
• Token ring switches
• FDDI switches
• Fast Ethernet switches
• Super-Switches or Mega-Switches support
• Multiple different LAN
• ATM
• WAN

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LAN Switch Methods

• Cut-through switches
• Fast
• No error checking
• Retransmitting
• Store-and-forward switches
• Slow
• Error checking
• Error-free cut-through switches
• Error checking
• Switch between cut-through store-and-forward
  depend on line condition

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Switch Management

• Flow control
• Buffers
• Backpressure false collision detection signal
• Monitoring
• Port mirroring
• Roving port mirroring
• Simultaneous RMON view using a shared memory
  multigigabit bus

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LAN Switch Analysis

• Switching methods cut through, stored and
  forward, error free stored and forward
• Network architecture Ethernet, token ring, FDDI,
  etc
• Port configuration and connection single device
  or multiple devices
• Full-duplex
• Internetworking routing or bridge or both
• Management SNMP

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ATM for LAN

• IP over ATM
• TCP/IP protocol stack to employ ATM services
• LAN emulation
• A translation layer to use ATM services

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LAN Media Alternatives

• Not twisted pair
• Unshielded twisted pair
• Shielded twisted pair
• Coaxial cable
• Fiber
• Microwave radio
• Satellite
• Infrared

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Not Twisted Pair Phone Wire

• Four-conductor station wire (RYGB)
• Not for data transmission
• Flat gray modular wire or gray satin or silver
  satin
• Data over short distance

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Unshielded Twisted Pair

• 22, 24, 26 American wire gauge(AWG)
• Twisted pair or unshielded twisted pair (UTP)
• Electrical noise other interference
• Electrical Industries Association/Telecommunicatio
  ns Industries Association (EIA/TIA) 5 grades
  (Cat 3 Cat 5 data grade)
• Attenuation
• Near-end crosstalk (NExT)
• Category 6
• Foil-twisted pair cable
• Data rate 600 MHz

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UTP Installation Mistakes

• Untwisting more than max 13 mm to wall plates or
  punch-down block
• Exceed maxi bend radius (increase cross talk)
• Tight wires too tight (cross talk)

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Shielded Twisted Pair

• Pros
• Less interference
• Faster speed
• Cons
• More expensive
• Physically larger and difficult to connect to a
  terminating block

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Coaxial Cable

• Pros
• Large bandwidth (400 - 600 MHz)
• High capacity
• Less interference
• Good for noise environment
• Cons
• Tapped easy (security problem)
• Bulky to install

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Fiber - I

• Types
• Single mode more expensive and capacity
• Multimode graded index medium expensive and
  capacity
• Multimode or multimode step index less expensive
  and capacity
• Inexpensive plastic or copper
• Expensive glass
• Pros
• High bandwidth
• No interference
• No crosstalk
• Small physical size and light weight
• Very secure
• Cons
• Repeater for long distance
• Expansive

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Fiber - II

• Standard
• Synchronous optical network (SONET) in US
• Synchronous digital hierarchy (SDH) in Europe
• Main cable - TAT-8
• 6 fiber optic
• 2 pairs for voice, video, and data
• 1 pairs for backup
• Regenerator every 43 miles

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Microwave Radio - I

• Characteristics
• Long distance
• 4-28 gHz frequency range
• Straight line transmission
• 20-30 miles between transmission towers
• Radio license by FCC

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Microwave Radio - II

• Pros
• Analog or digital signals
• For voice, data and television signals
• Long distance
• Cons
• Interference by heavy rain
• Straight line transmission
• Security
• Vendors
• Motorola
• Rockwell Communication Systems

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Satellite

• Characteristics
• Microwave radio transmission
• Uplink and downlink
• Three satellites for the earth
• Pros
• Analog or digital signals
• For voice, data and television signals
• Long distance
• Cons
• Security and encryption
• Propagation delay

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Infrared

• Light waves
• Line of sight
• Wireless communication between nearby equipment

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Circuit Ownership

• Private circuits
• Leased circuits
• Bypass
• Switched (dial-up) circuits
• Selection criteria
• Cost, speed, availability, reliability,
  maintenance, users requirements

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Circuit Identification

• Blue prints and document circuit and equipment
• Circuit number to each circuit for identification

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Assignment

• Review chapters 5-6
• Read chapter 7