CHAPTER 3: NETWORK CABLING AND HARDWARE DEVICES
Fiber-optic light sources
1 Diode laser 2 High-radiance light-emitting diode (LED). -The light produced by these technologies is in the infrared region of the light spectrum.
Punch down block
A device that connects one group of wires to another through a system of metal pegs.
Single-mode fiber cables
-Data transfers through the core using a single light path. -Core diameter is 8 - 10.5 microns. -Cable lengths can extend a great distance. -There is less modal dispersion, so bandwidths can be higher. -Higher-cost electronics are required to send signals down a single path. -It is optimized for 1310 nanometer (nm) and 1550 nm light sources. (Multi-mode and single-mode fiber cables are not interchangeable)
GG45 connector
-Has eight connectors. -Supports four pairs of wires. -Is backwards compatible with RJ45. -Has four additional conductors in the corners of the connector that duplicate and replace the four inner pins on the RJ45.
SC Connector - Fiber Optic
-Is used with single-mode and multi-mode cabling. -Has a push-on/pull-off connector that uses a locking tab to maintain connection. -Has a separate connector for each wire. -Uses a ceramic ferrule to ensure proper core alignment and prevent light ray deflection. -Mnemonics: "set-and-click" or "square connector."
MTRJ Connector - Fiber Optic
-Is used with single-mode and multi-mode cabling. -Is composed of a plastic connector with a locking tab. -Uses metal guide pins to ensure that it is properly aligned. -Has a single connector with one end that holds both cables. -Uses a ceramic ferrule to ensure proper core alignment and prevent light ray deflection. -Mnemonics: "mechanical transfer registered jack."
Wavelength division multiplexing (WDM)
-It joins several light wavelengths (colors) onto a single strand of fiber by using different wavelengths of laser light. -This enables light signals in both directions across a single fiber. -Today's systems can easily multiplex 160 signals. -It is mostly used by long-haul and high-speed providers. -Most systems are designed to be used with single-mode fiber.
Time-domain reflectometer(TDR)
A special device that sends electrical pulses on a wire to discover information about the cable. It measures impedance discontinuities (the echo received on the wire in response to a signal on the same wire). The results of this test can be used to identify several variables: -Estimated wire length. -Cable impedance. -The location of splices and connectors on the wire. -The location of shorts and open circuits.
Power over Ethernet(PoE)
A technology that allows a single cable to provide both data and electrical power to devices such as wireless access points, IP cameras, and VoIP phones. -used on twisted-pair Ethernet cabling (CAT 5 or higher). -Power is usually supplied by a ___-enabled Ethernet switch -can use a ___ injector to add ___ capability to regular network links and upgrade existing LAN installations to ___. To upgrade a network connection, patch it through the ___ injector.
Miswired cable
Caused by incorrect wire positions on both connectors. Several wiring problems might exist: -A reverse connection is a cable wired using one standard on one end and another standard on the other end. *This creates a crossover cable & can cause problems when it is used instead of a straight-through cable. This will reverse the transmit and receive match up; the transmit pins on one end maps to the transmit pins on the other end when they should map to the receive pins on the other end* -Wiremapping is matching a wire with a pin on one end with the same pin on the other end. Ex. an error in the wiremapping results when the wire at pin 1 connects to pin 4. -A split pair condition is a single wire in two different pairs reversed at both ends. *ex. if instead of the solid green wire, the solid brown wire is matched with the green/white wire in pins 1 and 2. Not following correct T568A/B standards, or when you connect cables using a punch-down block, pairs are not split. *With a split pair configuration, the cable might still work (especially if it is short), but it could introduce crosstalk.
F-type connector
Coaxial cable uses this connector -Twisted onto the cable or installed using a compression tool. -Used to create cable and satellite TV connections. -Used to connect a cable modem to a broadband cable connection.
Electromagnetic interference (EMI)
External signal that interferes with normal network communications. Ex. nearby generators, motors (such as elevator motors), radio transmitters, welders, transformers, and fluorescent lighting -When working with the radio frequency spectrum, this is known as radio frequency interference (RFI). -To protect from it use STP or fiber optic (immune to it),
Damaged and mismatched cables (Fiber Optic Performance Factors)
Fiber optic cable can break from bending too tight. -Wavelength mismatch causes serious issues with fiber optic cables. You cannot mix and match types of cable. ex. use the same type of mode single or multi and same diameters.
Connectors (Fiber Optic Performance Factors)
For light to pass through a fiber optic connector, the fiber within the jack must line up perfectly with the fiber in the connector. Several issues can occur when you are working with fiber optic connectors. -Using the wrong connector will result in misaligned fibers -Dirty cables and connectors can also impede or disrupt the light signal Several cleaning methods can be used with fiber optic connectors: -connectors where the ferrule protrudes out of the connector, ex. FC connector, you can wipe the end of the ferrule with a lint-free cloth that has a small amount of denatured alcohol applied. Immediately wipe the ferrule dry with a dry lint-free cloth. - connectors where the end of the ferrule is less accessible, you must use a specialized cleaning tool to plug the fiber optic cable into the tool and clean it by pumping the tool's handle. -To clean the jacks use special tool
10 Gigabit Ethernet
If Cat 7 cabling is used for _____, the cables are terminated with GG45 or TERA connectors. -GG45 connectors require a special set of tools that are different from the RJ45 crimping tool. -TERA connectors can be installed without any special tools.
Crosstalk
Interference caused by signals within the twisted pairs of wires -can reduce by twisting wires into pairs, each pair is twisted at a different rate. -often introduced within connectors where the twists are removed to add the connector. -can also occur where wires are crushed or where the plastic coating is worn Several types: ~Near-end ____(NEXT) is measured on the same end as the transmitter ~Far-end ______(FEXT) is measured on the end without the transmitter ~Alien ______ is introduced from adjacent, parallel cables.
Twinaxial Cable (Twinax)
Similar to a coaxial cable but it has two inner conductors instead of one. It was initially created and used by IBM but it's becoming more popular in short-range scenarios due to its high-speed differential signaling applications (1 Mbit/s).
MDF, IDF, and Patch Panels
To Document ______, ___, ________ -Develop a naming convention for cables, wall jacks, patch panel ports, network devices, and racks. -Record names in tables and diagrams (location, installation dates, cable lengths, and cable grades.) -Consider using documentation software
Pinout
When connecting two devices using twisted-pair cabling, the ____ determines which wire goes to which pin of the connector.
10-Mbps Ethernet over twisted pair (10BASE-T) + 100-Mbps Ethernet over twisted pair (100BASE-TX)
____ and ____ , use only two of the twisted pairs of wires in a Cat 3, Cat 5, or Cat 5e cable. -following pins are used for a computer NIC: 1: Transmit + 2: Transmit - 3: Receive + 6: Receive -, Pins 4, 5, 7, 8 unused.
1000Base-T Gigabit Ethernet
_____ uses all 4 pairs of wires in Cat 5e or above cables. -There are positive (+) and negative (-) pins for each pair of wires. -Signals go in both directions over each pair of wires, so there are no dedicated transmit and receive pins. -The T568A and T568B wiring standards are still used.
Far-end crosstalk (FEXT)
measured on the end without the transmitter. -For example, when a signal is sent on one wire pair, it measures the interference on an adjacent wire pair at the opposite connector end.
Main distribution frame(MDF)
-A frame or rack that is used to interconnect and manage telecommunication wiring in a building. -It functions like an old-time telephone switchboard, where operators used connecting wires to route telephone calls. -___ can also refer to the room that houses the traditional ___ along with networking patch panels.
FC connector - Fiber Optic
-Is typically used with single-mode cabling. -Has a separate connector for each wire. -Uses a threaded connector. -Is designed to stay securely connected in environments where it may experience physical shock or intense vibration. -Mnemonics: "ferrule connector" or "fiber channel."
ST Connector - Fiber Optic
-Is used with single-mode and multi-mode cabling. -Has a keyed bayonet-type connector. -Is also called a push-in and twist connector. -Has a separate connector for each wire. -Is nickel-plated with a ceramic ferrule to ensure proper core alignment and prevent light ray deflection. -Mnemonics: "set-and-twist" or "straight tip".
Krone LSA-PLUS
A European-style telecommunications connector.
Open circuit
A condition that results from a cut in the wire preventing the original signal from reaching the end of the wire. -Electricity cannot flow because the path is disconnected.
Distribution Panel
A patch panel for fiber optic cabling is called a fiber ____.
Light-emitting diode (LED)
A two-lead semiconductor light source that emits visible light when an electric current passes through it.
Fiber-optic cabling Advantages and Disadvantages
Advantages: -Immune to electromagnetic interference (EMI) -Highly resistant to eavesdropping -Supports extremely high data transmission rates -Allows long cable distances without a repeater. Disadvantages: -Is very expensive to install -Is difficult to work with -Requires special training to attach connectors to cables.
Riser space
An area that connects multiple floors where cables can be run. This area cannot be a plenum space.
Demarc extension
Can be used to move the demarc to another location in a building -You are responsible for installing the demarc extension, but the LEC might do it for an additional charge
Solid Cables (Twisted pair cables)
Conduct electrical signals better, but are prone to break when they are repeatedly bent. Used in permanent and semi-permanent installations.
Phone cable
Connector: RJ11. Description: This cable is used to connect a PC to a phone jack in a wall outlet to establish a dial-up internet connection. It is also used to connect a DSL modem to a telephone network. It has two pairs of twisted cable (a total of 4 wires).
Cat 8
Connector: RJ45 Description: This is the fastest Ethernet cable with data transfer speed of up to 40 Gb and bandwidth support of up to 2 GHz. Uses shielded foiled twisted pair construction that includes shielding around each pair of wires within the cable to reduce near-end crosstalk. It also uses braiding around the group of pairs to minimize electromagnetic interference in crowded network installations.
Cat 5
Connector: RJ45 Description: supports 100-Mb Ethernet (100BASE-TX) and ATM networking. Specifications also support gigabit (1000 Mb) Ethernet.
BIX cross-connect system
Cross-connect system made of different sizes of punch down blocks, cable distribution accessories (such as moulded rings and strips), and a punch down tool -Certified for Cat-5e Composed of two parts: -The mounts -The connectors
Riser rated cables
Designed for installations that run between floors. Requirements are not as strict as plenum requirements.
Twisted Pair Advantages
Flexibility, cost, ease of use, and support for newer protocols
Shielded twisted pair(STP)
Has a grounded outer copper shield around the bundle of twisted pairs or around each pair. This provides added protection against EMI. Most of the cables have a special grounding wire called a drain wire.
Coaxial Cable Advantages
Highly resistant to electromagnetic interference (EMI). Highly resistant to physical damage.
fiber-optic glass
In ___, these longer wavelengths have lower attenuation or signal loss due to scattering. Attenuation in ___ due to light absorption for these (850 nm, 1300 nm, 1310 nm, and 1550 nm) wavelengths is almost zero.
Krone LSA-PLUS (punch down block)
Insulation-displacement connector for telecommunications. It's a European alternative to the 110 block. -Also used in broadcast systems with audio interconnections. Can be used with associated control systems as well. Multipair audio cables are specifically designed for it.
Coaxial Cable Disadvantages
More expensive than UTP. Inflexible construction (more difficult to install). Not supported by newer networking standards.
Stranded cables (Twisted pair cables)
More flexible than solid cables, but don't carry signals as well. Used for patch cords and frequently moved cables.
Plenum space
Part of a building that provides a pathway for the airflow needed by heating and air conditioning systems, such as above a dropped ceiling or below a raised floor.
T568A Standard
Pin 1: GW = White with green stripe Pin 2: G = Green Pin 3: OW = White with orange stripe Pin 4: B = Blue Pin 5: BW = White with blue stripe Pin 6: O = Orange Pin 7: BrW = White with brown stripe Pin 8: Br = Brown
T568B Standard
Pin 1: OW = White with orange stripe Pin 2: O = Orange Pin 3: GW = White with green stripe Pin 4: B = Blue Pin 5: BW = White with blue stripe Pin 6: G = Green Pin 7: BrW = White with brown stripe Pin 8: Br = Brown
Punch Down Blocks
Predecessors to patch panels. Used to support low-bandwidth Ethernet and telephony wiring.
intermediate distribution frame (IDF)
Smaller wiring distribution frame or rack within a building. Like an MDF, the room that houses the ____ along with networking patch panels and rack-mounted equipment is called an ____. -Usually located on the floor above the MDF but can be added as needed -When above the MDF they're connected using a vertical cross-connect (VCC) or wire bundles that run vertically -When a floor has multiple ___s they are connected with a horizontal cross-connect (HCC)
Twisted Pair Disadvantages
Susceptible to interference and Susceptible to eavesdropping
Demarcation point(demarc)
The line that marks the boundary between the telecommunications (telco) equipment and your private network or telephone system. -(aka the minimum point of entry (MPOE) or the end user point of termination (EU-POT)) -In businesses its typically on the bottom floor of a building & residential its often a small box on the outside of the house The _____ may be ~A box on the wall with a simple RJ45 connection ~A 50-pin RJ21 connector ~A fiber-optic connection ~A port on a network interface device (NID
punch down tool
Use a _______ to insert wires into 66, 110, or krone blocks. -pushes the wire into the block and cuts off the excess wire. -position the blade on the side of the clip toward the end of the wire -blade for a 66 block is straight but for a 110 block its notched
Plenum rated cables
Use insulation that is fire resistant and non-toxic when burned. Must be used in plenum spaces but can also be used in riser spaces.
66 block (punch down block)
Used primarily for telephone applications its a punch down block used to connect individual copper wires together. -25 rows of four metal pins There are two different configurations 1. 25-pair block (aka non-split block), all four pins are bonded (electrically connected.) Used to connect a single wire with up to three other wires. 2. 50-pair block (aka split block), each set of two pins in a row are bonded. Used to connect a single wire to one other wire. -w/ 50-pair block, use a bridge clip to connect the left two pins to the right two pins. Adding or removing the bridge clip is an easy way to connect wires within the row for easy testing -be sure to purchase ___ rated for cat 5 -keep twist when inserting
110 block (punch down block)
Used to connect individual wires together. Used primarily for telephone applications. Preferable over 66 blocks because less crosstalk. -various sizes (ex.50,100,300) -Has rows of plastic slots. Each plastic slot connects two wires together (brick pushes them down and shuts it) -C4 (4pairs) C5 (5pairs) -when connection wires are WBl,Bl,WOr,Or,WGr,Gr,WBr,Br For data applications buy ones that are certified for Cat 5, Cat 6 and Cat 6a
Transceiver mismatch
Well-madnetwork devices have interfaces that can be tailored to different cable types, protocols, and speeds. This is done by connecting a hot swappable transceiver to the interface. -When connecting one network device to another, you must use matching transceivers. For twisted pair cabling, a mismatch in speed is a common issue.
Electrical short
When an electrical signal takes a path other than the intended path. -With twisted pair wiring, a short means that a signal sent on one wire arrives on a different wire.
RJ45 Crimper
When creating a twisted pair cable using RJ45 connectors: -Use a crimping tool -Determine whether the cable wires have solid cores or stranded cores. -Use the correct RJ45 connector type, solid or stranded. -Solid core cables: used for longer runs inside walls or the ceiling. -Stranded core wires: used for patch cables and for drop cables where frequent movement occurs and flexibility is needed. (Cat 6- and Cat 6a-compliant cables may not perform at 10 Gbps if the pairs are not twisted right up to the connector.)
Media Converters
When working with fiber optic cabling, you can use ___ to switch between different network media. For example, you can convert: -Single-mode fiber to copper Ethernet wiring. -Multi-mode fiber to copper Ethernet wiring. -Single-mode or multi-mode fiber to coaxial wiring. -Single-mode fiber to multi-mode fiber.
UTP Cable substitution
You can substitute each type of UTP cable for any category below it, but never for a category above. For example: -You can substitute Cat 6 for a standard requiring Cat 5e. -You can't use Cat 5 in a situation where Cat 6 is required. -The exception is Cat 7 cabling, and then only when Cat 7 is terminated with TERA connectors.
Patch panels (aka Distribution Panels)
___ permit circuits to be arranged and rearranged by plugging and unplugging respective patch cords on a mounted hardware assembly. -used in an MDF/IDF instead of punch-down b. -usually uses 4 pair cables because of the sheildinig -In large applications, 25- and 100-pair cables can be used for VCCs or HCCs. They should be certified for the desired network speed. -Twisted pairs are connected at the rear of the panel w/ a special tool -At the front of the panel, patch cables are used between the ____ and network devices.
Bad connector
a damaged connector that is causing connectivity issues. ex. a broken locking tab on an RJ45 connector, a bent or damaged pin especially on female RJ45 connections, and the center wire of a coaxial cables.
Loopback plug
aka loopback adapter, reflects a signal from the transmit port on a device to the receive port on the same device. Use the loopback plug to verify that a device can both send and receive signals. -There are loopback plugs for both copper and fiber connections. -A failure in the loopback test indicates a faulty network card. -A successful loopback test means the problem is in the network cabling or another connectivity device. -can purchase pre-made loopback plugs, or you can make an inexpensive one by cutting the end of a cable and manually connecting the transmit wires to the receive wires (put wire from pin 1 to the wire at pin 3, and the wire at pin 2 to the wire at pin 6.)
Known good spares
are a set of components that you know are in proper functioning order. If you suspect a problem swap it out. if it doesn't fix it then troubleshoot other components.
Alien crosstalk
introduced from adjacent, parallel cables. -For example, a signal sent on one wire pair causes interference on a wire pair that is within a separate twisted pair cable bundle.
Near-end crosstalk (NEXT)
measured on the same end as the transmitter. -For example, when a signal is sent on one wire pair, it measures the interference on an adjacent wire pair at the same connector end.
Incorrect Termination
occurs when an incompatible or incorrect connector is used. This can result in reduced performance or complete connection loss.
Short
occurs when electrical signals take a path other than the intended path. -with twisted pair wiring, a ____ means that a signal sent on one wire arrives on a different wire. -occur when two wires touch. This can be caused by worn wire jackets, crushed wires, or a metal object piercing two or more wires.
Impedance
the measure of resistance within the transmission medium. -is measured in ohms (Ω). -All cables must have the same ___ rating. The rating for the cable must match the of the transmitting device. -mostly a factor in coaxial cables used for networking. Be sure to choose cables with the correct rating (50 or 75 ohm) based on the network type -When signals move from cables with different ratings, some of the signal is reflected back to the transmitter, distorting it (aka echo). With video (cable TV), its the ghosting of the image.
Multi-mode fiber cables
-Data transfers through the core using multiple light paths. -Core diameter is 50 to 100 microns. -There is more modal dispersion due to the multiple paths. -Cable lengths are limited in distance and are dependent on bandwidth. -Higher light-gathering capacity simplifies connections and allows lower-cost electronics. -It is optimized for 850 nm and 1300 nm light sources. (Multi-mode and single-mode fiber cables are not interchangeable)
TERA Connector
-Has eight connectors. -Supports four pairs of wires. -Is incompatible with RJ45 and GG45. -Does not require special tools to install.
When installing fiber optic cable
-Keep the area as clean as possible. -Cut the cable with a clean 90-degree cut. -Polish the end of the cable prior to adding the connector. Use special polishing film and tools for polishing the cable ends. -Glue or crimp the connector onto the cable. -Cover or cap any connectors that won't be hooked up immediately. -If necessary, directly splice two cable ends together. This requires expensive and specialized equipment.
XFP
A 10-Gigabit small form-factor pluggable transceiver that is similar to an SFP in size but is used for 10-Gigabit networking.
Wiring diagram
A map of the physical connections and physical layout of the electrical system/circuit in a building. It shows how the electrical wires are connected. It can also display where fixtures and components can connect to the system.
Firewall
A network security system (router) that monitors and controls incoming and outgoing network traffic based on predetermined security rules. -can be programmed with security rules to restrict the flow of traffic between networks. -A ___ can be either hardware devices or software installed onto operating systems. operates at the Network layer (Layer 3) of the OSI model. some operate at higher layers
Reverse Address Resolution Protocol (RARP)
A protocol that hosts use to find the IP address of a host with a known MAC address.
Layer 3 switch
A switch capable of reading Layer 3 (network) addresses and routing packets between subnets. -often provides better performance than a router, but it does not support as many features as a router.
Gigabit Interface Converter (GBIC)
A transceiver that converts electrical signals to optical signals and vice versa in fiber optic and Ethernet systems.
Small Form Factor Pluggable (SFP)
A transceiver that is similar to a GBIC but is smaller in size. An ___ is sometimes called a mini-GBIC.
Speed Test Website
An online tool that is used to test the bandwidth of your internet connection. Provides: -Connection latency (ping) -Download speed -Upload speed
Racks (Equipment Organization)
Can house multiple network devices in a vertical stack. Also, make it much easier to organize network cabling. In addition, it allows the following devices to share physical resources such as: -Cooling fans -Power supplies -Peripherals using a keyboard, video, and mouse (KVM) device
Cat 7
Connectors: GG45 or TERA Description: Standard was ratified years before the Cat 6a standard to support 10-Gbps Ethernet (10GBASE-T). It requires shielding on each twisted pair and the cable as a whole.
Main distribution frame (MDF)/intermediate distribution frame (IDF) documentation
Documentation relating to ____ and ___ includes the following: -Standard Operating Procedure (SOP): This document is a set of step-by-step instructions to help IT, and maintenance workers, with complex routine operations. The instructions are very detailed to minimize the chance of errors. -Policies can be created as a guide and documentation for ____ and ___ . Policies are usually placed in the organization's quality manual. Policies give a course of action to guide and influence decisions.
Repeater
It receives, regenerates, amplifies, and retransmits the electrical signals it receives. It also removes the effects of attenuation. -A hub can sometimes be called a ___ because its main function is to accept an electrical signal coming in on one port and forward that same signal out to all of the other ports. However, many other devices can also be used as a ___.
Optical time-domain reflectometer(OTDR)
Performs the same function as a TDR, but is used for fiber optic cables. An ___ sends light pulses into the fiber cable and measures the light that is scattered or reflected back to the device. The information is then used to identify specifics about the cable: -The location of a break. -Estimated cable length. -Signal attenuation (loss) over the length of the cable.
Logical (network diagram)
Shows how traffic flows across the network. It includes information such as IP addresses, admin domains, how domains are routed, control points, and so on. If you're using the OSI model, ___ diagrams are referred to there as L2.
hub
The central connecting point of a physical star. It uses a logical bus topology. They manage communication among hosts using the following method: 1 A host sends a frame to another host through the __. 2 The ___ duplicates the frame and sends it to every host connected to the ___. 3 The host to which the frame is addressed accepts the frame. Every other host ignores the frame. They are Layer 1 devices; they simply repeat incoming frames without examining the MAC address in the frame.
Blade devices (Equipment Organization)
They are very thin. They are designed to provide high device density and the most efficient use of available rack space.
Fiber optic cabling
To connect computers using ____, you need two fiber strands. One sends and one receives signals. Long-haul runs sometimes need only one fiber. The send and receive signals are transmitted over the same fiber. Components: -The core carries the signal. It is made of glass or plastic. -The cladding maintains the signal in the center of the core as the cable bends. -The sheathing protects the cladding and the core.
Coaxial Cable Grade RG-6
Uses: Cable TV, satellite TV, and cable networking Resistance Rating: 75 ohms
Polishing (Fiber Optic Performance Factors)
insertion loss: Whenever a connector is installed on the end of fiber optic cable, a degree of signal loss occurs. -Additionally, some of the light that is lost is reflected directly back into the cable, toward the source. This is called back-reflection or optical return loss (ORL). Polish ratings -Physical contact (PC): polishing is usually used with single-mode fiber. The ends of the fiber are polished with a slight curvature so that when the cable end is inserted into the connector, only the cores of the fiber touch each other. -Super physical contact (SPC) and ultra physical contact (UPC) polishing use a higher grade of polish and have more of a curvature than PC polishing. -Angled physical contact (APC) polishing is used to reduce back reflection as much as possible. (An APC connector has an eight-degree angle cut into the ferrule. The angle cut prevents reflected light from traveling back into the fiber can only use with other APC connectors.
RJ45 connector
-Has eight connectors. -Supports up to four pairs of wires. -Uses a locking tab to keep the connector secure in an outlet. -Is used for Ethernet and some Token Ring connections. (This connector type is almost identical to RJ45. It uses the same connector as an RJ45, but it is wired differently. It is used for specific WAN connections, such as a T1 line.)
Smartjacks
A More intelligent NID that may be provided by the LEC _____S: -Maintained by the LEC. -Used for more complex services, like a T1 line. -Can provide signal conversions, buffer signals, and regenerate signals. -May provide diagnostic capabilities for the LEC. -The loopback capability can be used to test signals by transmitting them back to the LEC. -Alarm indicators can report trouble to the LEC. -Indicator lights can show the configuration and status of the ____. -Internet provider can test connection and send commmands -When you contact a WAN service provider for assistance they may test it -A successful test indicates that the problem is within the customer premises equipment (CPE).
Coaxial cable
A Relatively old technology that is usually implemented with a bus topology. It is not suitable for ring or star topologies because the ends of the cable must be terminated. It has the following components: -Two concentric metallic conductors. The inner conductor is a solid wire made of copper or copper-coated tin. -The outer mesh conductor (shield) is made of aluminum or tin-coated copper. -A PVC plastic insulator that surrounds the inner conductor and insulates the signal from the mesh conductor. -A PVC plastic cable sheath (jacket) that surrounds and protects the wire.
Rack diagram (aka rack elevation)
A ___ is a map of the layout of IT equipment within a server rack. It's used to manage and track data center assets. Just as with the floor plan diagram, there are software options available to help you create a ___ more easily.
Floor plan
A ____ diagram shows the physical location of each piece of network equipment within the company's premises. Making a network ___ is often done using software that creates the diagrams. The software creates a visual representation of physical components along with a clearly defined set of principles and procedures.
Building Industry Cross-Connect (BIX)
A cross-connect system. It consists of various sizes of punch down blocks, cable distribution accessories, and a punch down tool to terminate wires on the punch down block.
Labeling
A hardware/wiring configuration that makes perfect sense when you initially put it together may be mystery a year later when you try to troubleshoot problems with it. Consider ___: -Switch ports -Patch panel connections -Wall jacks -Electrical circuits -Devices and systems Define (and abide by) a naming convention to uniquely identify each component. It will vary based upon the network and the organization's needs. Consider the following: -All file servers are named FSx (such as FS1, FS2, and so on) -All printers are named PTRx -All workstations are named WSx -All switches are named SWx -All routers are named RTRx
Cat 6a
Connector: RJ45 Description: Designed to provide better protection against EMI and crosstalk than Cat 6 cabling. Provides better performance than Cat 6, especially when used with 10-Gbps Ethernet (10GBASE-T).
Cat 6
Connector: RJ45 Description: Supports 10-Gbps Ethernet (10GBASE-T) and high-bandwidth broadband communications. In most cases, Cat 6 cables include a solid plastic core that keeps the twisted pairs separate and prevents the cable from being bent too tightly.
Cat 5e
Connector: RJ45 Description: similar to Cat 5 but provides better EMI protection. It supports 100-Mb (100BASE-T) and gigabit (1000BASE-T) Ethernet
Signal loss (Fiber Optic Performance Factors)
Light signals being transmitted through a fiber optic cable experience attenuation, or ____, as they pass through the cable due to: -reflection: A measurable amount of light is reflected when it hits the ends of the cable -Refraction - If the light hits the boundary between the core and the cladding at too steep of an angle, the light is refracted into the cladding instead of reflected back into the core, causing signal loss. -Scattering - Impurities in the fiber core can cause light to scatter. -Absorption - Impurities in the fiber can also absorb the light, converting it to another form of energy, such as heat. This is a major cause of signal loss. Several physical cable attributes can contribute to signal loss: -Cable length, Connectors, splices, and bends You can estimate how much signal loss (measured in dB) you should reasonably expect in a given run of fiber optic cabling. -calculated by summing the average loss of all the components used in the cable run to generate an estimate of the total attenuation called a loss budget -When calculating a loss budget for a segment of fiber optic cable, use the following guidelines. *Connectors: 0.3 dB loss each. *Splices: 0.3 dB loss each. Multi-mode cabling: *3 dB loss per 1000 meters when using an 850 nm light source. *1 dB loss per 1000 meters when using a 1300 nm light source. Single-mode cabling: *0.5 dB loss per 1000 meters when using a 1310 nm light source. *0.4 dB loss per 1000 meters when using a 1550 nm light source. The total attenuation should be no more than 3 dB less than the total power at the transmission source. This is called the link-loss margin.
Messaging (Process)
Steps of the ___ process: 1 The sending host prepares a packet to be sent. The host uses its own IP address as the source Network layer address and the IP address of the final receiving device as the destination Network layer address. 2 The sending host creates a frame by adding its own MAC address as the source Physical layer address. For the destination Physical layer address, the host uses the MAC address of the default gateway router. 3 The sending host transmits the frame. 4 The next hop router reads the destination MAC address in the frame. Because the frame is addressed to that router, it processes the frame. 5 The router strips off the frame header and examines the packet destination address. It uses the routing table to identify the next hop router in the path. 6 The router repackages the packet into a new frame. It uses its own MAC address as the source Physical layer address and the MAC address of the next hop router as the destination Physical layer address. 7 The router transmits the frame. 8 The next hop router repeats steps 4 - 7 as necessary until the frame arrives at the last router in the path. 9 The last router in the path receives the frame and checks the destination IP address contained in the packet. 10 Because the destination device is on a directly connected network, the router creates a frame using its own MAC address as the source Physical layer address and the MAC address of the destination device as the destination Physical layer address. 11 The router transmits the frame. 12 The destination device receives the frame. Inside the packet, it finds that the destination Network layer address matches its own IP address, and the source IP address is that of the original sending device. Note the following: -Both Data Link layer physical addresses and Network layer logical addresses are used to send packets between hosts on different subnets. -IP (Network layer) addresses are contained in the IP header; MAC (Data Link layer) addresses are contained in the Ethernet frame header. -Data Link addresses in the frame change as the frame is delivered from hop to hop. At any point in the process, the Data Link destination address indicates the physical address of the next hop on the route. The Data Link source address is the physical address of the device sending the frame. -Network addresses remain constant as the packet is delivered
Fusion splicer
Tool that uses heat to join two optical fibers together. It fuses them together end-to-end. This is done when the cable is broken or too short for the purpose it's being used for. -eliminates (as much as possible) any light being scattered or reflected back by the splice. -The source of heat used by the fusion splicer is usually an electric arc, but could also be a laser, a gas flame, or a tungsten filament through which current is passed.
Twisted Pair Standards
Two copper conductors form a path for an electrical signal with each wire carrying an equal but opposite signal. The wires are twisted to reduce crosstalk (the absorbed signals from another pair). The conductors are 22- to 24-gauge in thickness and are covered in plastic insulation. Pairs are color-coded, bundled together, and covered in a plastic jacket or sheath. Most cables contain four twisted pairs. Cables may contain 25 or 100 pairs when used in larger wiring applications. Each pair within a length of cable is given a different number of twists to further reduce the effects of crosstalk.
Unshielded twisted pair(UTP)
Two twisted wires that carry the data signals (one conductor carries a positive signal; one carries a negative signal). Twisting the cables reduces the effects of electromagnetic interference (EMI) and crosstalk. Cheaper and Easier than STP
Coaxial Cable Grade RG-58
Uses: 10Base2 Ethernet networking (also called thinnet) Resistance Rating: 50 ohms
Power over Ethernet (PoE) Cabling
_____ technologies allow network cables to carry electrical power. -Helpful for remote devices where no external power is available. Including digital telephone systems where handsets are powered through the Ethernet cable. -Power can be supplied through one of the unused pairs of wires in 10- and 100-Megabit Ethernet or by using one of the data wires. -Many network switches have the option to supply -____injection devices can be added to the middle of the cable span.
Toner probe
composed of two devices used together to trace the end of a wire from a known endpoint to the termination point in the wiring closet. to use one: -Connect the tone generator to one end of the wire. It will send a signal on the wire. -In the wiring closet, touch the ____ to wires or place the ___ close to wires. A sound at the ___ indicates that the generated tone has been detected and the wire that you are touching is the termination point for the wire you are tracing.
Multimeter
device used to test various electrical properties. A ___ can measure several parameters: -AC and DC voltage -Current (amps) -Resistance (ohms) -Capacitance -Frequency
RJ11 Connector
-Has four connectors. -Supports up to two pairs of wires. -Uses a locking tab to keep the connector secure in an outlet. -Is used primarily for telephone wiring.
crossover cable
-If a network device such as a hub or switch does not have an uplink port, use a ____ when connecting it to another network device. -You can also connect one computer directly to another using a ___. -It maps the transmit pins on one end of the cable with the receive pins on the other end -You can easily create a ___ as follows: ~Use the T568A standard to attach an RJ45 connector to one end. ~Use the T568B standard to attach an RJ45 to the other end.
Local exchange carrier(LEC)
-In the United States, ___ is a term used for a public telephone company that provides local services. -Sometimes called telcos.
LC Connector - Fiber Optic
-Is used with single-mode and multi-mode cabling. -Is composed of a plastic connector with a locking tab that is similar to a RJ45 connector. -Has a single connector with two ends to keep the two cables in place. -Uses a ceramic ferrule to ensure proper core alignment and to prevent light ray deflection. -Is half the size of other fiber optic connectors. -Mnemonics: "lift-and-click" or "little connector."
straight-through cable
-Most twisted pair cables are manufactured as _______s -Connects computers to a hub or switch -The pinout order on a computer's network interface card (NIC) is different than the pinout order on the hub or switch port. -Transmit pins of the NIC map to the receive pins on hub or switch and vice versa.
RJ45 Wiring Conventions
-There are two Telecommunications Industry Association (TIA) standards for creating straight-through cables. It doesn't matter which standard you use, T568A or T568B. -Once you choose a standard, you should use the same one for all cables to avoid confusion when troubleshooting.
1Wire Stripper, 2Snips, 3Crimpers
1___ remove the protective sheath of a cable in order to expose the conductive wire. -rated to specific gauge ranges. most are combo tools that can strip, cut, and crimp cables. Almost all have multiple holes for specific cable sizes. 2____cutting tools used to cut cables or wires to a specific length or to remove damaged sections. A diagonal cutter is an example. 3___ is used to attach connectors to wires. Some are designed for power connections. A special one is used to attach RJ45 connectors to twisted pair cables.
Bridge
A device that connects two (or more) media segments on the same subnet. It filters traffic between both segments based on the MAC address in the frame. It builds a database based on MAC addys to use for making forwarding decisions. -Starts by examining the source MAC of an incoming frame. If the source addy is not in the forwarding database, an entry for the addy is made in the database, associating the MAC with the media segment. -The destination addy is then examined. *If the destination addy is not in the database, the frame is sent out on all segments except for the one on which it was received. *If the destination addy is in the database, the frame is forwarded to the appropriate segment if the segment is different from the one on which it was received. *Broadcast frames are forwarded to all segments except the one on which they were received. You should be aware of the following regarding bridges: -They are used to separate one part of a subnet from another. This eliminates unnecessary traffic between segments -All segments connected to a ___ are on the same subnet and share a common subnet address. -They can connect two segments that use different types of network architecture. -They are Layer 2 devices; they read the MAC addys contained in a frame to make forwarding decisions. -Frame forwarding happens independently of the upper-layer protocols (such as TCP/IP).
Router
A device that connects two or more network segments or subnets. -Each subnet has a unique logical network address. -can be used to connect subnets within a single LAN, or they can be used as gateways to connect multiple LANs together. -can be used to connect networks with different architectures (for example, connecting an Ethernet network to a token ring network). They maintain information about other networks in a database called a routing table. The routing table typically contains the address of all known networks and the next router in the path used to reach the destination network. The routing table is used in the process of forwarding packets. operates at the Network layer (Layer 3) of the OSI model
Network Interface Card (NIC)
A hardware device that connects a computer to the network medium. It is responsible for converting binary data into a format that can be sent on the network medium. A ___ is also called a network adapter. -A transceiver is responsible for converting digital data into digital signals to be sent on the medium. (A fiber optic NIC = light signals, a wired NIC = electronic signals on a wire, and a wireless NIC = radio signals.) -To receive signals, the transceiver converts digital signals from the network to digital data for the PC -A modem converts binary data to analog waves on the sending end (modulation) and then converts the analog waves back to binary data on the receiving end (demodulation). -some comps come with built in nics and others you have to plug -Network interface cards are Layer 1 devices because they send and receive signals on the network medium. They are also Layer 2 devices because they must follow the rules for media access and because they read the physical address in a frame -Older network interface cards used an external transceiver
Wireless access point (WAP)
A hub for a wireless network. As with a hub, a message sent to any wireless host connected to it can be received by all other wireless hosts. -its a Layer 2 device; it can read the Data Link layer address in a frame. -It is often configured as a bridge, connecting a wireless segment to a wired segment. Both wireless and wired hosts are on the same subnet. -Some are combination devices that include a wired switch and even a router.
Cable certifier
A multi-function tool that verifies that a cable or an installation meets the requirements for a specific architecture implementation. ex: you would use a ___ to verify that a drop cable meets the specifications for 1000BaseT networking. -very important for Cat 6 cable used with bandwidths at or above 1000 Mbps. slight errors can cause speed of 100mbps -can also validate the bandwidth capabilities of network interface cards and switches -include features of a toner probe, TDR, and cable tester -very $$$
Switch
A multi-port bridge that performs filtering based on MAC addresses and provides additional features not found in a bridge. -While most bridges can process only a single frame at a time, ___ can process multiple frames simultaneously -___ offer guaranteed bandwidth to each switch port. -It can make additional forwarding decisions based on the MAC address. ex: It can be configured to accept frames from specific MAC addresses. -Like bridges, it operates at Layer 2. -Unmanaged switches are autonomous in their function, requiring no port management or configuration. Managed switches allow administrators to change the port configurations, including the following: *Port speed, Duplexing, Filters based on network adapter MAC addresses, and VLAN assignment*
Address Resolution Protocol (ARP)
A protocol that hosts use to discover the MAC address of a device from its IP address. Before two devices can communicate, the MAC address of the receiving device must be known. If the MAC address isn't known, ARP does the following to find it: 1. The sending device sends out a broadcast frame. -The destination MAC address is all Fs (FFFF:FFFF:FFFF). -The sending MAC address is its own MAC address. -The destination IP address is the known IP address of the destination host. -The sending IP address is its own IP address. 2 All hosts on the subnet process the broadcast frame, looking at the destination IP address. 3 If the destination IP address matches its own address, the host responds with a frame that includes its own MAC address as the sending MAC address. 4 The original sender reads the MAC address from the frame and associates the IP address with the MAC address, saving it in its cache. Once the sender knows the MAC address of the receiver, it sends data in frames addressed to the destination device. These frames include a cyclic redundancy check (CRC) that is used to detect frames that have been corrupted during transmission.
QSFP
A quad (4-channel) small form-factor compact hot-pluggable transceiver that is also used for data communication applications
Media Access Control (MAC)
A unique identifier burned into the ROM of every Ethernet NIC. The first half of the ___ address (the first six digits) is assigned to each manufacturer. The manufacturer determines the rest of the address, assigning a unique value that identifies the host address. -12-digit (48-bit) hexadecimal number (each number ranges from 0-9 or A-F). -often written as 00-B0-D0-06-BC-AC or 00B0.D006.BCAC. Dashes, periods, and colons can be used to divide the address parts. -Devices use the ___ address to send frames to other devices on the same subnet.
Attenuation
The loss of signal strength from one end of a cable to the other. aka: dB loss. -The longer the cable, the more ___. Never exceed the maximum cable length defined by the networking architecture -Cables at a higher temperature experience more ___ -A repeater regenerates the signal
Transceiver module (Network Interface Card Components)
Used to change the media type of a port on a network device, such as a switch or a router. The following are the most common types of ___: -A gigabit interface converter (GBIC) is a large one that fits in a port slot and is used for gigabit media, including copper and fiber optic. -A small form-factor pluggable (SFP) is similar to a GBIC, but is a smaller size. An SFP is sometimes called a mini-GBIC. -SFP+ is a newer version of the SFP. SFP+ supports data rates as high as 10 Gbit/s, 8 Gbit/s Fiber Channel, 10 gigabit Ethernet, and the Optical Transport Network (OTU2 standard). -A 10 gigabit small form-factor pluggable (XFP) is similar to an SFP in size, but is used for 10 gigabit networking. -Quad (4-channel) SFP is a compact hot-pluggable that is also used for data communication applications.
Media converter (Network Interface Card Components)
Used to connect network interface cards that are using different media types. ex. could be used to connect a server with a fiber optic Ethernet NIC to a copper Ethernet cable. -___ work at the Physical layer (Layer 1) and do not read or modify the MAC address in any way. -They convert one media type to another within the same architecture (such as Ethernet). It cannot translate between two different architectures. This must be done using a bridge or a router. Converting from one architecture to another requires modifying the frame contents to modify the Data Link layer address.
Environmental monitor
does what its name implies, it monitors the environmental conditions of a specific area or device. -often used to track the conditions within server rooms, ex. temperature, humidity, water, smoke, motion, and air flow. -Typically, computers (especially servers) have an internal monitor that measures fan speed and CPU temperature -many sound an alarm if a specified temperature or other environmental condition is reached
Media adapters and transceivers (Fiber Optic Performance Factors)
lots of network switches and routers allow you to insert a transceiver like a gigabit interface converter (GBIC) in an empty slot to convert the interface from copper wiring to fiber optic. -Other devices use a small form-factor pluggable (SFP) transceiver to accomplish the same goal. Several issues can occur when using these and other fiber optic media adapters: -Some GBIC/SFP modules use multimode fiber; others use single-mode -Media adapter modules malfunction on occasion
Throughput
the rate that signals are processed and delivered over a communication channel. Some facts about ____: -Each circuit module has a specified link bandwidth and estimated ___. Larger number designations usually mean more bandwidth. -Most modern wireless access points can be configured to run in the 5-gigahertz mode, 2.4-gigahertz mode, or mixed mode. The access point supports both standards, meaning that one radio runs 5-gigahertz, and the other runs 2.4-gigahertz. Be aware: ~Support for both modes is convenient because it supports a wide range of devices. It also presents a problem because you can't use a 2.4-gigahertz radio for your 5-gigahertz communications ~You can turn the 2.4-gigahertz off and use that extra radio and antenna for your 5-gigahertz clients and increase ____ using MIMO. -Another factor is the antenna used to transmit the signal. Just as there are differences between access points, there are also differences between antennas. ex. if you buy a cheap antenna, then ____is impacted and your range is reduced.
Voltage event recorder
tracks voltage conditions on a power line. -Basic ___track only undervoltage or overvoltage conditions. -More advanced devices track conditions over time and create a graph, saving data from a program running on a computer. -Some UPS systems include a __. Use a ___ to identify periods of low or high voltage that can adversely affect network components.
cable tester (line tester)
verifies that the cable can carry a signal from one end to the other and that all wires are in the correct positions. -High-end ones can check for various miswire conditions such as wire mapping, reversals, split pairs, shorts, or open circuits. -can use it to quickly identify a crossover and a straight-through cable. -most have a single unit that tests both ends of the cable at once. also a second unit that can be plugged into one end of a long cable run to test the entire cable.
Tap splicer
vinyl plastic wire termination device with a sharp metal insert that cuts through the plastic insulating jackets of two wires and crimps them together. -use it to make quick splices or connections
