Networking Fundamentals

Cable types and connectors

Fiber

• A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves. Fiber optics have several advantages over traditional metal communications lines: Fiber optic cables have a much greater bandwidth than metal cables.

• Connectors: SC, ST and LC

SC Connector

• (Standard Connector, Subscriber Connector) A fiber-optic cable connector that uses a push-pull latching mechanism similar to common audio and video cables. For bi-directional transmission, two fiber cables and two SC connectors (Dual SC) are used. SC is specified by the TIA as FOCIS-3.

ST Connector

• ST (an AT&T Trademark) is probably still the most popular connector for multimode networks (ca. 2005), like most buildings and campuses. It has a bayonet mount and a long cylindrical 2.5 mm ceramic (usually) or polymer ferrule to hold the fiber. Most ferrules are ceramic, but some are metal or plastic.

LC Connector

• The LC connector licensed by Lucent Technologies provides a pull-proof design and small size perfect for high-density applications. Available in simplex or duplex versions. The LC connector is provided with a 1.25mm zirconia ferrule.

Twisted pair

• Twisted pair cabling is a type of wiring in which two conductors of a single circuit are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources; for instance, electromagnetic radiation from unshielded twisted pair(UTP) cables, and crosstalk between neighboring pairs

• Connectors: RJ-11, RJ-45

• Wiring Standards: T586A, T586B

Connectors

• RJ-11• Used for telephone line

• RJ-45• Used for Ethernet connections

Wiring Standards: T586A, T586B

Coaxial

• Connectors: BNC; F-connector

Characteristics of connectors and cabling

Fiber

• Types: Single mode vs multimode

• Speed and transmission limitations

• Multimode fiber is optical fiber that is designed to carry multiple light rays or modes concurrently, each at a slightly different reflection angle within the optical fiber core.

• In optical fiber technology, single mode fiber is optical fiber that is designed for the transmission of a single ray or mode of light as a carrier and is used for long-distance signal transmission. For short distances, multimode fiber is used. Single mode fiber has a much smaller core than multimode fiber.

• Multimode = 10Gbps over 550meters

• Single mode = 10Gbps over 40Km

Fiber-Optic Cables and Connectors• Fiber-optic cabling transmits

signals with light rather than with electrical signals

• Immune to electrical interference. (EMF)

• Used primarily as a backbone between networks or large LANS

• Fiber-optic cable comes in two major types:

• Single-mode• Has a thin core (between 8 and

10 microns) designed to carry a single light ray long distances.

• Multimode• Has a thicker core (62.5 microns)

than single-mode; carries multiple light rays for short distances.

• Fiber-optic devices and cables use one of several connector types.

• SC Uses square connectors• ST Uses round connectors• FC Uses a round connector

Fiber-Optic Cables and Connectors• As with connectors there are

various fiber optic cable types

• Cables as represented by connectors also have standards for cable construction.

• These include single mode, multi mode etc

• Content and construction can also differ

• While other cables can be made “at home” fiber optic cable is generally done by manufacturers or specially trained technicians with specialized equipment.

Twisted pair

• Types: STP, UTP, CAT3, CAT5, CAT5e, CAT6, CAT6e, CAT7, plenum, PVC

• Speed and transmission limitations

• Splitters and effects on signal quality

Types: STP, UTP, CAT3, CAT5, CAT5e, CAT6, CAT6e, CAT7• STP = Shielded Twisted Pair

• UTP = Unshielded Twisted Pair

• CAT3• 10base-T, 10Mbps 100Meters

• CAT5• 100base-T, 100Mbps, 100Meters

• CAT5e• 1000base-T, 1Gbps, 100Meters

• CAT6• 10GBase-T, 10Gbps, 55Meters

• CAT6e• 10GBase-T, 10Gbps, 100Meters

• CAT7• 10GBase-T, 10Gbps, 100Meters

Plenum, PVC

• Plenum• Used for in wall, ceiling, resists toxic fumes

• PVC• Standard patch cable, will give off fumes

Coaxial

• Types: RG-6, RG-59

• Speed and transmission limitations

• Splitters and effects on signal quality• Will reduce signal

RG 6

• All of the new demands required by, satellite signals and broadband internet made it necessary to find a more effective coaxial cable. RG6 cable was designed to fulfill these requirements. It has a larger conductor, which gives you much better signal quality. The dielectric insulation was made thicker as well, which means it is much less likely to carry an electric current that could damage your sensitive electronics. RG 6 is also made with a different kind of shielding, which allows it to more effectively handle Ghz level signals.

RG 59

• RG 59 is good for lower frequency signals (anything under about 50 MHz). That makes it a good choice for a closed circuit television (CCTV) video surveillance system. You can even make your installation easier by getting what’s called “Siamese coaxial cable.” This cable consists of a RG 59 cable merged together with a 2C power cable. By using this type of cable you can run the power and video for your security cameras simultaneously, effectively cutting your install time in half. Also some older HD TV’s still use lower frequencies (around 37 MHz), making RG 59 a better choice for them.

Internet connection types, network types and features

Network Types

LAN

• A local area network (LAN) is a network that connects computers and other devices in a relatively small area, typically a single building or a group of buildings. Most LANs connect workstations and personal computers and enable users to access data and devices (e.g., printers and modems) anywhere on the network.

WAN

• A wide area network (WAN) is a geographically distributed private telecommunications network that interconnects multiple local area networks (LANs). In an enterprise, a WAN may consist of connections to a company's headquarters, branch offices, co-location facilities, cloud services and other facilities. Typically, a router or other multifunction device is used to connect a LAN to a WAN. Enterprise WANs allow users to share access to applications, services and other centrally located resources. This eliminates the need to install the same application server, firewall or other resource in multiple locations, for example.

PAN

• A personal area network (PAN) is a computer network used for data transmission amongst devices such as computers, telephones, tablets and personal digital assistants.

• Location is within the vicinity of the person

MAN

• A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by even a large local area network (LAN) but smaller than the area covered by a wide area network (WAN)

Network architecture devices, functions and features

Hub

• A hub is a common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Switch

• A network switch (also called switching hub, bridging hub, officially MAC bridge) is a computer networking device that connects devices together on a computer network, by using packet switching to receive, process and forward data to the destination device.

Router

• A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet. A data packet is typically forwarded from one router to another through the networks that constitute the inter-network until it reaches its destination node.

Access point

• A device that allows users to connect to a resource, typically network.

• In a wireless local area network (WLAN), an access point is a station that transmits and receives data (sometimes referred to as a transceiver). An access point connects users to other users within the network and also can serve as the point of interconnection between the WLAN and a fixed wire network. Each access point can serve multiple users within a defined network area; as people move beyond the range of one access point, they are automatically handed over to the next one. A small WLAN may only require a single access point; the number required increases as a function of the number of network users and the physical size of the network.

Bridge

• A bridge is a type of computer network device that provides interconnection with other networks that use the same protocol. Bridge devices work at the data link layer of the Open System Interconnect (OSI) model, connecting two different networks together and providing communication between them.

Modem

• Short for modulator-demodulator. A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves

Firewall

• a part of a computer system or network that is designed to block unauthorized access while permitting outward communication.

• Can be software or hardware

Patch panel

• A panel of network ports contained together, usually within a telecommunications closet, that connects incoming and outgoing lines of a LAN or other communication, electronic or electrical system.

Repeaters/Extenders

• Any device that will take a signal, clean it up, amplify it and re transmit it.

• A wireless repeater (also called wireless range extender) takes an existing signal from a wireless router or wireless access point and rebroadcasts it to create a second network. It can be a specialized stand alone computer networking device.

Ethernet over power

• Networking over power cabling is easier than you think. Most people have a wireless network in their home these days. So you might think that Powerline networking (aka Home Plug), which uses your home's electrical wiring as a wired data network, is an outdated and redundant technology.

Power over Ethernet injector

• PoE injector. A device that adds power to an Ethernet cable for Power Over Ethernet (PoE) equipment. Although Ethernet switches are available with PoE capability, millions of regular "non-PoE" switches are already installed.

Servers, Workstations, NOS, peer to peer, client server

Network Topologies

Network Topologies• Mesh

• All computers on the network are connected directly to each other. Typical example: Wi-Fi ad hoc network.

• Ring• All computers pass information from computer to

computer in either a physical ring layout (typical example: FDDI network) or a logical ring layout (typical example: Token Ring).

• Bus• All computers share a common cable. Typical

examples: 10BASE2 (Thin net Ethernet) or 10BASE5 (Thick net Ethernet).

• Star• All computers connect to a central point (hub,

switch, or access point). Typical examples: Wired Ethernet (10/100/1000BASE-T), wireless Ethernet running in infrastructure mode.

• Hybrid• Combination of any two or more of the above

networks. For example, a mesh net- work connecting via a bridge to a star network. The combination is a hybrid network.

Command-Line Tools for Networking

• NET• Various options for displaying and using network resources

• PING• Checks network and Internet connectivity

• TRACERT• Traces route to specified IP address or URL

• IPCONFIG• Displays system’s IP address and other information

• NSLOOKUP• Displays detailed information about DNS

• NETSTAT• Displays current TCP/IP network connections and protocol stats

LAB

• Network discovery

• Know what you are working with

• Check connection types

• Check network settings

• Use GUI or command prompt tools

• Ping, ipconfig, nslookup, tracert

• Know the tools inside and out

• Document the network. Use redirection if wanted.

Checking for connectivity

• Use of visual queues… • Lights on network card (amber and green) what do they represent

• Network icon (shows connectivity)

• Network properties (send and receive amounts and rates)

• Use command prompt (preferred)• Several tools available to check for connectivity

Command prompt tools

• Using the command prompt

• Command /? For information on the command (help file)

• We will use the following commands• ipconfig

• ping

• nslookup

• tracert

Continue testing

• Ping the following addresses• 127.0.0.1

• Your assigned IP address (use ipconfig)

• You gateway address

• Your DNS address

• Your destination• Destination can include FTP, website etc.

• Use nslookup to get site IP address if needed.