Network Systems 3.01 Understand the physical components of a network.

Network Technology Network Technology Network Devices Types of Network Systems Transmission Media Linking to the Internet

Goals Understand Purpose of Network Identify Network Devices Identify Types of Systems Identify Network Devices

Network device Definition: A device is a component used to connect computers or other electronic devices together so they can share files or resources. Use: Performs tasks like routing and communicating Types of Devices: Router, Switch, Modem, Access Point

Router Definition A hardware device or software program that manages the paths along which information travels within and between networks A router uses the IP address to determine the pathway. Advantages Intelligent software that enables it to pass data quickly across the network Disadvantages Requires configuration Required for SOHO configurations

Switch Definition A device that links multiple computers, telephones, cameras, alarms, or networks on the same data connection Provides individual connections for each host within the local network. The switch uses the MAC address to determine the pathway. MAC stands for Media Access Control The MAC address is the hardware address of the NIC (Network Interface Card) on the end device. It is unique for every device.

Switch Advantages Break-up collision domains (fewer collisions) Faster transfer rate than hub Improves the throughput of Ethernet networks Disadvantages Does not create IP addresses No intelligent software

Wireless Access point Definition Joins wireless clients to a wired Ethernet network Also known as “hot spots” Advantages Mobility Network flexibility Disadvantages Security vulnerability Signal interference and limited number of frequencies Placement

modem Definition Performs the functions of a modulator and a demodulator Used with a dial-up Internet connection. Modulator Enables computers to interpret data received from a network Demodulator Allows a modem to send information formatted to be read by network computers

End device Definition: A device that is either the source or the destination of a packet on a network. Every device must have an IP address, MAC address and Network Interface Card. Examples: Computer, Printer, Server, VOIP phones, cameras and alarms

Host (computer) Definition A computing device on a computer network Responsibilities / Tasks / Role / Functions Manages tasks, communicates instructions, or delivers specific services to other computers, or clients, on a network It is the destination of a message sent through a network. It includes computers, mobile phones, scanners and printers. Also known as… Computer Terminal Node

Network printer Definition A printer that allows for multiple users to print from remote locations of the network It contains its own network interface card, and requires its own IP and MAC address.

server Definition A computer with the software capabilities that provides services to other computer programs and their users. Types File Server DHCP & DNS Database Web Print Gaming Email Music

VOIP Phones Definition The method of delivering video and voice communications over a computer network Advantages Cheaper than the land lines Disadvantages Must have electrical current

Security cameras Definition A digital camera connected to a computer network that allows the user to record video. Commonly used for surveillance. Advantages Powered with Ethernet cable Small, portable and easily accessibility Models can be wireless Disadvantages High network bandwidth Requires lots of digital storage space

Security and fire alarms Definition A system in place for monitoring your home and business environment.

Types of network systems Systems that provide service to users across a network

Personal area network (PAN) Service Area A network created around an individual’s personal workspace Example The connection between a Smart phone and a laptop

Local area network (LAN) Service Area A network created for a home or other small geographic area Types Physical Wireless Example A network in a school or classroom

Local area network (LAN) More facts Consists of high speed network infrastructure at a single location used to deliver network applications and services Ethernet is widely used in a LAN network. It has a lower cost than other transmission media. It is easier to use than other transmission media. It has the capability to scale up to and past multi-gigabit speeds.

Transmission media Definition Provides a path for information to be sent from one computer to another through a network Types of Transmission Media: Coaxial cable Ethernet cable Fiber optic cable Wireless transmission

Coaxial cable Definition Cable specifically designed for carrying an electronic signal Two variations- ThinNet and ThickNet Features: Max Cable Length is 200 meters (ThinNet) or 500 meters (ThickNet) Cost (Twisted Pair < Coaxial < Fiber Optic) Ease of Installation (Moderately difficult to install) Susceptible to EMI and RFI interference Consists of four layers of material to reduce interference

Twisted pair cable Definition Cable commonly used in high-speed wired computer networks Features: Cable Length (Up to 100 meters) Cost (Twisted pair is the cheapest) Ease of Installation (Easy to install) Susceptible to EMI and RFI interference Twisted pair wiring reduces interference Types Straight-through Crossover Rollover (console cable)

Unshielded twisted pair (UTP) Found in Ethernet and phone systems Most common type of cable used for computer networks. Used for short to medium distances (up to 100 meters) Not shielded against EMI or other interference

Shielded twisted pair (STP) Found in Ethernet and phone systems Shielded to protect against EMI More costly than UTP Used for short to medium distances (up to 100M)

Fiber Optic cable Definition Cable made of super-thin filaments of glass or other transparent materials that can carry beams of light Features: Cable Length (Longest transmission, use of light) Cost (Fiber Optic is most expensive) Ease of Installation (Difficult to install)

Fiber Optic cable More Features: Less susceptible to interference Data can be sent at the speed of light. A LASER transmitter encodes frequency signals into pulses of light: ones and zeros are sent through the cable. The receiving end of the transmission translates the light signals back into data which can be read by a computer.

Ethernet standards The Institute of Electrical and Electronics Engineers (IEEE) defines wired transmission in the 802.3 standard. Typically written as XBaseT (X= transmission speed) T= Twisted pair cable. Note: The first two standards listed do not use twisted pair cabling. 10Base2- Thin Coaxial cable (ThinNet) 10Base5- Thick Coaxial cable (ThickNet) 10BaseT- Original twisted pair standard 100BaseT- Fast Ethernet 1000BaseT- Gigabit Ethernet 10GBaseT- 10GB Ethernet

Wireless transmission Definition Able to connect computers to other computers and printers the same way a wired network is, but without wires. Features: Range (Depends on factors such as wireless card, access point, and obstacles in between) Cost (Wireless price is dependent upon the complexity of the setup.) Ease of Installation (Easy) 802.11 (a,b,g,n) Interference can be caused by cordless telephones and microwaves Wireless security includes: WEP, WPA, and WPA2

Wi-fi Wireless Fidelity The original standards for wireless networks were put out by IEEE in 1990. These standards are also called Wi-Fi, or Wireless Fidelity. SSID The service set identifier, or SSID, is a name that identifies a particular Wi-Fi network to a wireless device. The SSID is required, can be up to 32 characters long and is case-sensitive.

802.11 Wireless standards Designation Ratification Date Wireless Band Data Rate 802.11 1997 2.4 GHz 2 Mbps 802.11a 1999 5 GHz 54 Mbps 802.11b 11 Mbps 802.11g 2002 802.11n 2009 2.4 GHz and 5 GHz 54 Mbps to 600 Mpbs

802.11 wireless security WEP WEP or Wired Equivalent Privacy uses a 64 or 128 bit key. WEP keys are vey insecure. Various attacks allow users to gain unauthorized access to the network.

802.11 wireless security WPA Wi-Fi Protected Access was designed to improve upon WEP’s features. Two improvements over WEP are: Improved data encryption the temporal key integrity protocol (TKIP). User authentication which allows only authorized network users access.

802.11 wireless security WPA2 WPA2 added a new Advanced Encryption Standard (AES) mode with mathematically proven security. WPA2 offers a Pre-shared key (PSK) mode for SOHO use. The PSK may be entered as a string of 64 hexadecimal digits or a passphrase. Shared-key WPA remains vulnerable to password cracking attacks if users rely on a weak passphrase.

Connecting to the internet Internet Service Provider In order to access the Internet and the World Wide Web you will need an Internet Service Provider (ISP) The ISP is a company that has a permanent connection to the Internet. A computer requires an ISP in order for communication software to work Once again every device will need a MAC address, IP address and Network Interface Card.