Local Network Hardware: LAN vs WAN

Comparing Local Network Hardware: Objectives

• Network types are compared based on the area over which parts of the network are managed
• Network hardware across LANs should be compared and contrasted
• Network cabling types and the advantages/disadvantages of each should be explained
• Wireless network types, standards and frequency bands should be compared

Comparing Network Types

• A network type characterizes the area over which network parts are managed
• Correct terminology classifications help distinguish specific requirements

Common Network Types

• LAN (Local Area Network)
• WAN (Wide Area Network)
• MAN (Metropolitan Area Network)
• PAN (Personal Area Network)
• SOHO (Small Office Home Office) and Enterprise Networks
• Datacenters and Storage Area Networks

Local Area Network (LAN)

• LANs connect computers via cabling and network switches in a single geographic location
• LANs can span a single floor, a whole building, or multiple nearby buildings (a campus)
• Any network where nodes are within 1 or 2 km of each other is considered "local"
• LAN cabling and devices are primarily owned and managed by the organization using the network

Wireless Local Area Network (WLAN)

• WLANs use radio waves and antennas for data transmission and reception
• Wi-Fi and Ethernet technologies often complement each other within the same local network
• Wired and wireless networking adapters enable communication

Wide Area Network (WAN)

• A WAN spans multiple geographic locations
• The Internet is a global network of networks and an example of a WAN
• Internet Service Providers (ISPs) facilitate access to the Internet
• Most private or enterprise WANs use cabling and equipment leased from an ISP to interconnect two or more LAN sites
• WANs are used by companies to connect branch offices to the LAN at the head office

Metropolitan Area Network (MAN)

• MAN refers to a network covering an area equivalent to a city or municipality
• It could describe a company with multiple connected networks within the same metropolitan area
• MANs are larger than LANs but smaller than WANs

Personal Area Network (PAN)

• PANs connect devices wirelessly over a few meters
• PANs can share data between PCs, mobile devices, and wearable tech like smart watches
• PANs can connect PCs and mobiles to peripherals like printers, headsets, speakers, and video displays
• PANs will continue to grow as more digital and network functionalities are embedded in everyday objects

Small Office Home Office (SOHO) LAN

• SOHO LAN is a business-oriented network used with a centralized server in addition to client devices and printers
• SOHO often uses a single networking appliance to provide LAN and Internet connectivity
• SOHO configurations are referred to as a "SOHO router," "Internet router," or "broadband router”

Datacenters and Storage Area Networks

• Networks distinguish between two basic computer roles:
  • Server - Dedicated to running network applications and hosting shared resources
  • Client - Allows end users access to applications and resources
• The datacenter is dedicated to provisioning server resources in a purpose-built facility
• Datacenters are installed with dedicated networking, power, climate control, and access control for critical applications

Storage Area Network (SAN)

• SANs provision access to a configurable pool of storage devices for application servers
• SANs are isolated from the main network and only accessed by servers, not client PCs
• SAN clients are database and application servers
• SANs are flexible and reliable due to provisioning a shared storage pool over each server machine using connectivity technologies like Fiber Channel and Internet SCSI (iSCSI)

Comparing Network Hardware

• Networking hardware allows computers to connect to a network over a network media type, and this forwards data between computers
• Network adapters, patch panels, and switches are used to implement local Ethernet networks
• Understanding Ethernet device functions and capabilities prepares you to support local office or SOHO networks

Network Interface Cards (NICs)

• Ethernet communications establish electrical signaling over copper twisted pair or light pulses over fiber optic cable
• The physical connection to the cable is made using a transceiver port in the computer's NIC
• In order for the NIC to process digital data signals, the signals are divided divided into regular units
• Ethernet provides a data link protocol to perform framing and addressing functions, including means for each node to address communications to other nodes
• Each Ethernet NIC port has a unique hardware/physical address, called the MAC (media access control) address which is identified in the source and destination MAC addresses

Patch Panels

• Typical office cabling connects computers to a wall port, running to a patch panel
• Cables running through the walls are terminated to insulation displacement connector (IDC) punch-down blocks at the back of the panel
• The other side of the patch panel has prewired RJ45 ports
• Patch cords connect a port on the patch panel to a port on an Ethernet switch
• Cabling design easily changes how any wall port location is connected to the network via switch ports

Hubs

• Hubs have ports; typically 4-48, where each computer is cabled to one port
• Circuitry repeats an incoming transmission from a computer attached to one port across all other ports
• Effectively, computers are attached to the same cable as computers attached to a hub
• Each computer attached to a hub receives all the traffic sent by other connected devices
• Frames that do not match a computer's MAC address are ignored
• This connection scheme is a "collision domain", where performance is reduced as only one computer can send a frame at a time
• If two computers try to send at the same time, collisions occur

Hub Facts

• The more computers connected to a hub, the more collisions occur
• Computers contend for a share of the media bandwidth and all communications are half-duplex
• Half-duplex means that computers can send or receive, but not at the same time.

Switches

• Switches decode each frame to identify the source and destination MAC addresses
• Track which MAC source addresses are associated with each port so it can forward an incoming frame to a port that is a match for the destination MAC address
• Each switch port is a separate collision domain, eliminating contention effects
• Each computer has full duplex connection to the network and can send and receive simultaneously at the network speed supported by the cabling and NIC

Unmanaged and Managed Switches

• Unmanaged switches perform functions without being configured
• Powering on and connecting hosts establishes ethernet connectivity without further intervention
• Managed switches function out of the box. An administrator can connect over a management port, configure security settings, and then choose options

Additional Switch Facts

• Most managed switches are designed to be bolted into standard network racks
• Typical workgroup switches have 24-48 access ports for client PCs, servers, and printers
• These switches have uplink ports, allowing connections to other switches

Power over Ethernet (PoE)

• PoE supplies electrical power from a switch port over ordinary data cabling to a powered device (PD), such as Voice over IP (VoIP) handset, camera, or wireless access point
• A PoE-enabled switch is referred to as end-span power sourcing equipment (PSE)
• When a device is connected to a port on a PoE switch,the switch runs a detection phase to determine whether the device is PoE enabled
• The device’s power consumption is determined and an appropriate supply voltage level is set
• If a device is not PoE enabled, the PoE switch will not supply power over the port

Additional PoE Switch Facts

• Powering devices through a switch is more efficient than AC adapters
• Network management software allows control of the devices and to apply energy saving schemes

Comparing Network Cabling Types

• Recognizing suitable cabling options for a given scenario will determine the best choice for network location
• Gaining knowledge and experience of cable installation and testing tools will help create reliable networks.

Unshielded Twisted Pair (UTP)

• UTP uses a copper wire construction
• UTP contains four copper conductor wire pairs that are twisted at different rates from each other to reduce interference
• The electrical signals sent over each pair are balanced, as each wire carries an equal but opposite signal to its pair
• Electrical signaling methods are reliable over a limited range, as signals lose strength over longer ranges (attenuation)
• Most UTP cable segments have a maximum recommended distance of 100m

Shielded Twisted Pair (STP)

• STP cable provides extra protection against interference and is used for 10G Ethernet and higher within datacenters
• Shielding is a requirement in settings involving high levels of external interference
• Screened cable has a thin outer foil shield around all pair
• Fully shielded cabling has a braided outer screen and foil shielded pairs and comes in various forms

Cat Standards

• A Cat specification rates twisted pair cable construction methods for use with given Ethernet standards
• Higher Cat specification cable is able to manage higher data rates
• Cat specifications are defined in the TIA/EIA-568-C Commercial Building Telecommunications Cabling Standards

Cat Standard Transfer Rate, Max Distance, and Ethernet Support

• Cat 5: 100 Mbps, 100m, 100BASE-TX (Fast Ethernet)
• Cat 5e: 1 Gbps, 100m, 1000BASE-T (GB Ethernet)
• Cat 6: 1 Gbps, 100m, 1000BASE-T (GB Ethernet); 10 Gbps, 55m, 10GBASE-T (10 GB Ethernet)
• Cat 6A: 10 Gbps, 100m, 10GBASE-T (10 GB Ethernet)

Copper Cabling Connectors

• Twisted pair Ethernet cabling uses terminated modular RJ45 connectors
• RJ45 connectors is referred to as “8P8C”, standing for eight-position/eight-contact
• Each conductor in four-pair Ethernet cable is color-coded, where each pair is assigned a colour (orange, green, blue, and brown)
• The first conductor in each pair has a predominantly white insulator with stripes of the colour; the second conductor has an insulator with the solid colour

Copper Cabling Installation Tools

• Divide into groups to discuss copper cabling installation tools and copper cable test tools to demonstrate each group's understanding:
  • Copper Cabling Installation Tools:
    • Cable stripper and snips
    • Punchdown tool
    • Crimper
  • Copper Cabling Test Tools:
    • Cable tester
    • Toner probe
    • Loopback plug

Network Taps

• Network taps intercept signals passing over a cable and send them to a packet or protocol analyzer
• Taps are either powered or unpowered:
  • A passive test access point (TAP) is a box with ports for incoming and outgoing network cabling and an inductor or optical splitter that copies the signal to a monitor port unaffected by load
  • An active TAP is a powered device that performs signal regeneration. Active taps are required for gigabit signaling over copper wire or fiber links that are affected by optical splitting

Copper Cabling Installation Considerations

• Cabling installation must comply with local building regulations and fire codes requiring the use of specific cable types
• Plenum Cable:
  • Plenum space is a void in a building carrying HVAC systems
  • Plenum is space is a false ceiling or raised floor used for communications wiring
  • Plenum space is an effective fire conduit, as spaces have high airflow and lack fire breaks
  • Plenum cabling should not emit smoke when burned, be self-extinguishing, and meet fire safety standards

Direct Burial Cable

• Outside Plant (OSP) cabling runs on external building walls or between buildings and is susceptible to weathering
• Aerial cable is strung between two poles or anchors with cable vulnerable to UV rays and changes to temperature
• Conduit can provide more protection for buried cable runs, though regular PVC cable should not be used
• Direct burial cable is laid and covered in earth or cement/concrete

Optical Cabling

• Optical cabling used to support higher bandwidth links, measured in multiple gigabits or terabits per second compared to electrical
• Optical is measured in miles, and copper wire is measured in feet
• The medium uses light pulses from lasers and LEDs, which are not susceptible to electrical interference
• An optical fiber consists of an ultra-fine core of glass to convey light pulses surrounded by a glass or plastic cladding guides and the outer cladding has a coating called the buffer
• The fibre optic cable is contained in a protected jacket and terminated by a connector

Broad Optical Cabling Categories

• Single-mode fiber (SMF):
  • SMF has a small core (8–10 microns) and carries a long wavelength (1,310 or 1,550 nm) infrared signal from a laser diode
  • SMF cables support up to 10 Gbps or higher with cabling ranging many kilometers, dependant on cable quality and optics
• Multi-mode fiber (MMF):
  • MMF has a larger core (62.5 or 50 microns) and carries a shorter wavelength infrared light (850 nm or 1,300 nm)
  • MMF uses LEDs, which is less expensive to deploy than SMF
  • MMF speeds and distances are not as great as single-mode with preference over LANs

Coaxial Cabling

• Coaxial (coax) cable is a copper cable carrying electrical signals
• Coax cancels out interference with a shared axis approach in contrast to twisted pair's use of balancing
• The core signal conductor is enclosed by plastic insulation (dielectric) then a second wire mesh conductor acting as shielding from Electronic Magnetic Interference, and a ground
• Coax is now mostly used for CCTV installations and patch cable for Cable Access TV (CATV) and broadband cable modems

Comparing Wireless Network Types

• Wireless technologies now achieve sufficient bandwidth to replace wired ports and is a convenient access method for SOHO networks
• Wireless provides connectivity for desktops and even server with cable difficult to install
• Understanding wireless technologies help in install, configure, and troubleshoot wireless standards and devices to provide effective support

Access Points

• Access points can establish a wireless-only network, or can work as a bridge to forward communications between wireless stations and a wired network
• Wired networks are often called a ‘distribution system’ (DS)
• The access point is connected to the network in much the same way as a host computer via a wall port and cabling to an Ethernet switch
• Enterprise networks use Power over Ethernet (PoE) to power the AP over the data cabling:

Wireless LAN Installation Considerations

• Clients identify an infrastructure WLAN through the network name or service set identifier (SSID) configured on the access point
• SSIDs can be 32 bytes in length using ASCII letters and digits with hyphen and underscore characters

Bluetooth

• Bluetooth connects peripheral devices to PCs and mobiles to share data between systems such as portable devices, smartphones, tablets, wearable tech, audio speakers, and headphones
• Transfers via radio communication speeds up to 3 Mbps. (Adapters supporting version 3 or 4 of the standard can achieve faster rates (up to 24 Mbps) )

Radio Frequency ID (RFID)

• RFIDs identifies and tracks objects using specially encoded tags that respond with programmed information when scanned
• RFID tags can be either an unpowered, passive device that requires close range (about 25 m) or a powered, active device up to around 100 m
• Passive RFID tags can be embedded in stickers and labels to track parcels and equipment
• RFID is also used to implement some types of access badge to operate electronic locks

Near Field Communications (NFC)

• NFC is a peer-to-peer version of RFID, functioning as both tag and reader to exchange information with other NFC devices
• NFC normally works at up to two inches (6 cm) at data rates of 106, 212, and 424 Kbps
• NFC sensors and functionality are being incorporated into smartphones to become contactless payment readers, security ID tags, and shop shelf-edge labels for stock control
• Used to configure types of connection and pair Bluetooth devices