1. NETWORK CABLING Chapter 2
The focus of this chapter is local area network (LAN) cabling technologies, such as coaxial, twisted pair, and fiber optic. Students need to know how to identify them, install them, and recognize their strengths and weaknesses.
Focus on cabling types, connectors, and topologies that are used to build LANs. Make sure students understand the external and internal installation methods and when to use them. Also cover cabling and installation tools.

2. Chapter 2: NETWORK CABLING
TOPOLOGIES
There are three main local area network (LAN) topologies:
Bus
Star
Ring
Other network topologies include:
Mesh
Wireless
Make sure students understand that the data-link layer architecture dictates the topology and cabling that can be used. Students should be able to distinguish between topologies when they are given a schematic diagram or description. This is covered in exam objective 1.1.

3. Chapter 2: NETWORK CABLING
Bus Topology
Bus Topology Failure
BUS TOPOLOGY
The bus topology supports thick and thin coaxial segments.
Segments are connected by repeaters.
The bus topology uses the baseband signaling method.
Signals are broadcast in both directions simultaneously.
Both ends of each segment require termination to avoid reflection.
End systems connect to the segment in a linear manner.
Describe how end devices attach to the cabling segment. Explain the advantages and disadvantages of this topology. Explain how signals travel in both directions simultaneously along the cable. Also explain the function of terminators and signal reflection.

4. THICK AND THIN COAXIAL BUS
Chapter 2: NETWORK CABLING
THICK AND THIN COAXIAL BUS
Briefly introduce the connection hardware and termination devices. Cabling and connectors are covered in more detail later in this chapter.
Discuss how repeaters are used to extend the overall distance of the network. Repeaters are covered in Chapter 3, “Network Connection Hardware.” In the exam, students must be able to distinguish the type of network when they are given just a diagram. You might want to stress this point to them so they pay more attention.

5. Chapter 2: NETWORK CABLING
Star Topology
STAR TOPOLOGY
The star topology can use coaxial, twisted pair, or fiber optic cable.
A central device (hub) connects hubs and nodes to the network.
Each node connects to its own dedicated port on the hub.
Hubs broadcast transmitted signals to all connected devices.
You can connect multiple hubs to form a hierarchical star topology.
The star topology uses the baseband signaling method.
A coaxial star is rare. This type of configuration was used in ARCNet networks. The most common cable type used now is twisted pair. You can use fiber optic cable to extend the distance between segments.

6. Chapter 2: NETWORK CABLING
A SIMPLE STAR TOPOLOGY
You might want to mention that the maximum distance for twisted pair is 100 meters (328 feet). Make sure students understand that signals sent through a hub are broadcast (amplified and bit repeated) to all attached devices. Point out that layer 2 devices, such as a switch or a bridge, can direct the transmission to a specific port.

7. A HIERARCHICAL STAR TOPOLOGY
Chapter 2: NETWORK CABLING
A HIERARCHICAL STAR TOPOLOGY
Explain to students that a hierarchical star is simply a series of connected hubs, switches, or bridges. You might want to briefly cover how many hubs the half-duplex, 10-Mbps Ethernet and Fast Ethernet implementations allow in a single collision domain.
Also discuss how hubs are connected to form a hierarchical star. Full-duplex connections are not subject to collisions.

8. Chapter 2: NETWORK CABLING
Ring Topology
Ring Topology Failure
RING TOPOLOGY
The ring topology can use twisted pair or fiber optic cabling.
A central device (hub) connects hubs and nodes to the network.
Each node connects to its own dedicated port on the hub.
You can connect multiple hubs to form a larger ring.
The ring topology uses the baseband signaling method.
Frames are transmitted around the ring from node to hub to node.
Media Access Control (MAC) is used for token passing.
Give examples of this topology, such as Fiber Distributed Data Interface (FDDI) and Token Ring. Both of these topologies implement dual counter rotating rings for fault tolerance. One ring is used as the primary path for data. The second ring is used as a backup path, which is only used when the primary path fails. To achieve the full benefit of fault tolerance, the ring must not have an open end. There is a ring wrap function within the central hub or dual attachment station (DAS) in FDDI that allows the ring to continue to operate even when there is one open end.
Both of these technologies support token passing. With token passing, there are no collisions. There is only one token per ring at all times. The Early Token Release feature allows for the transmission of multiple frames on a ring and the early release of the token. This does not mean that there is more than one token on the ring.

9. Chapter 2: NETWORK CABLING
A RING NETWORK
You might want to talk about Multistation Access Units (MSAUs) and their functions in the network. Discuss how Token Ring MSAUs can be added to the network to form a bigger ring by using the RI (Ring In) and RO (Ring Out) ports. Now might be a good time to show the Ring Topology and Ring Failure videos.

10. Chapter 2: NETWORK CABLING
MESH TOPOLOGY
Typically uses fiber optic cabling for redundant wide area network (WAN) links
Provides multiple paths to destinations for fault tolerance
Supports baseband and broadband signals
Requires an enormous amount of cable
The mesh topology is used primarily as a backbone internetwork infrastructure for enterprise networks. Point out the advantages and disadvantages of using this topology in a LAN.

11. Chapter 2: NETWORK CABLING
LAN MESH

12. Chapter 2: NETWORK CABLING
ENTERPRISE MESH
A full mesh in the enterprise wide area network can be created by using point-to-point physical circuits from each site to every other site. However, it is far more common to use a logical full mesh of connectivity by connecting PVCs (using frame relay or ATM) at every site or by using an MPLS VPN, which provides full mesh connectivity through the carrier’s routed infrastructure.

13. Chapter 2: NETWORK CABLING
WIRELESS TOPOLOGY
Cell-based technology that uses unbounded media
Two wireless topologies:
Ad hoc
Infrastructure
Describe unbounded media and the two wireless LAN (WLAN) technologies used to implement wireless networks. Also describe range and basic service area (BSA) concepts.

14. Chapter 2: NETWORK CABLING
AD HOC WLAN
Consists of two or more wireless devices communicating directly with each other.
Signals generated are omnidirectional out to a range determined by environmental factors and equipment used (called the basic service area).

15. Chapter 2: NETWORK CABLING
INFRASTRUCTURE WLAN
Uses a wireless device called an access point as a bridge between wireless devices and a standard cabled network.
Wireless devices communicate only with the access point; they do not communicate with each other directly

16. Chapter 2: NETWORK CABLING
CABLING STANDARDS
Three organizations developed the T568-B cabling standards document:
American National Standards Institute (ANSI)
Electronic Industries Alliance (EIA)
Telecommunications Industry Association (TIA)
Cabling standards include
Performance levels
Topologies
Segment distance limitations
Connectors
Pinouts
Installation guidelines
Explain the relevance of the T568-B document for both voice and data. Describe the subsystems defined in the standard as they relate to cabling a building.

17. Chapter 2: NETWORK CABLING
LAN CABLE TYPES
Three cable types are used in LANs:
Coaxial
Twisted pair
Fiber optic
Discuss the similarities and differences of each of the cable types and discuss when to use each one.
It could be extremely helpful to the students if you can show them physical samples of the cabling and connector types discussed in this chapter. Pass them around and have the students examine them as you discuss each one. Students must be able to recognize the media connectors associated with each cable type. This is covered by exam objective 1.4.

18. Chapter 2: NETWORK CABLING
COAXIAL CABLE
Note that the cable type here is RG-62, not RG-8 (thick coaxial) or RG-58 (thin coaxial). RG-62 and RG-58 look very similar. You can briefly mention that RG-62 cable was originally used to connect IBM miniframes and mainframes and was also used in ARCNet LANs in a star topology. (Do not attempt to teach the students about miniframes, mainframes, or ARCNet.)
Point out that plenum cabling does not generate toxic gases when it burns. Thick coaxial cable was typically used as a backbone cabling system within a building or between building and outdoors because it can reach much farther distances than thin coaxial can. You can describe thick coaxial cable like this: it is somewhat like a frozen garden hose, and just as pliable.
Now is a good time to mention the distance limitations of coaxial cable for Ethernet. Thick coaxial segments are limited to 500 meters (1640 feet). Thin coaxial segments are limited to 185 meters (607 feet).

19. Chapter 2: NETWORK CABLING
Thin Ethernet
COAXIAL CABLE
RG-8
RG-58
Application
Thick Ethernet
AKA 10Base5
Thin Ethernet
AKA 10Base2
Thickness
0.405 inch
0.195 inch
Connector Type N
BNC with a T-fitting
Max cable length Segment
500 meter
200 meters (Actually 185)
Note that the cable type here is RG-62, not RG-8 (thick coaxial) or RG-58 (thin coaxial). RG-62 and RG-58 look very similar. You can briefly mention that RG-62 cable was originally used to connect IBM miniframes and mainframes and was also used in ARCNet LANs in a star topology. (Do not attempt to teach the students about miniframes, mainframes, or ARCNet.)
Point out that plenum cabling does not generate toxic gases when it burns. Thick coaxial cable was typically used as a backbone cabling system within a building or between building and outdoors because it can reach much farther distances than thin coaxial can. You can describe thick coaxial cable like this: it is somewhat like a frozen garden hose, and just as pliable.
Now is a good time to mention the distance limitations of coaxial cable for Ethernet. Thick coaxial segments are limited to 500 meters (1640 feet). Thin coaxial segments are limited to 185 meters (607 feet).

20. AUI (ATTACHMENT UNIT INTERFACE) CABLE
Chapter 2: NETWORK CABLING
AUI (ATTACHMENT UNIT INTERFACE) CABLE
Describe how an AUI cable connects to the AUI port on a node or repeater. You might mention that this is an example of the cabling covered in slide 2 of this chapter.

21. THIN ETHERNET HARDWARE
Chapter 2: NETWORK CABLING
THIN ETHERNET HARDWARE
Describe all the hardware in the diagram. Terminators are 50 ohm.

22. UNSHIELDED TWISTED PAIR (UTP) CABLE
Chapter 2: NETWORK CABLING
UNSHIELDED TWISTED PAIR (UTP) CABLE
Explain the reason for the twists in UTP cable. Point out that this type of cabling can be used in both data and voice networks. Data networks typically use two of the four pairs, while voice networks only use a single pair. One of the pairs transmits and the other receives. Ethernet networks use pins 1 and 2 to transmit and pins 3 and 6 to receive.

23. Chapter 2: NETWORK CABLING
UTP CONNECTORS
RJ-45 Connector
Point out that RJ-45 connectors are used for data networks. RJ-11 connectors are used for voice networks.

24. Chapter 2: NETWORK CABLING
UTP CABLE GRADES
Category
Frequency
Primary Application 1
Up to 0 MHz
Voice networks 2
Up to 1 MHz
Voice and low-speed data networks less than 4 Mbps 3
Up to 16 MHz
Voice and data networks from 4 to 100 Mbps 4
Up to 20 MHz
16-Mbps Token Ring 5
Up to 100 MHz
100-Mbps Fast Ethernet 5e
1000-Mbps Gigabit Ethernet 6
Up to 250 MHz
Describe how cable grades are defined. Stress the importance of selecting the appropriate cable for an installation. Also, make sure students understand that all connecting hardware must support the same grade or category cable to achieve the specific grade level.
The Category 3 (CAT3) 100-Mbps rating applies only to 100Base-T4 and 100VG AnyLAN. 100Base-T4 requires the use of all four pairs.
Focus on CAT3, 5, 5e, and 6. The only cable grades worth mentioning for shielded twisted pair (STP) are Type 1a and Type 6a. They are both 2-pair, 22-gauge cables with extra shielding to reduce interference and crosstalk. Type 1a is used for backbones and horizontal wiring, and Type 6a is used for patch cables. These STP cables were found in Token Ring networks. You might want to have students go to Table 2-1 in the textbook and follow along here.

25. Chapter 2: NETWORK CABLING
FIBER OPTIC CABLE
Explain the differences between multimode and singlemode fiber.
Differences include thickness of core and cladding (62.5/125 microns vs. 8.3/125 microns, respectively)
The primary differences are that singlemode fiber uses a single-wavelength laser as a light source, can carry signals for extremely long distances, is relatively expensive, and better suited to WAN environments. Multimode fiber uses a light-emitting diode (LED) that carries multiple signals, can carry signals a shorter distance, is less expensive, and better suited for LAN environments.

26. STRAIGHT TIP (ST) CONNECTOR
Chapter 2: NETWORK CABLING
STRAIGHT TIP (ST) CONNECTOR
The term "stab-and-twist" is sometimes used to describe how the ST connector connects.

27. SUBSCRIBER CONNECTOR (SC)
Chapter 2: NETWORK CABLING
SUBSCRIBER CONNECTOR (SC)
The term "stab-and-clip" is sometimes used to describe how the SC connector connects.

28. Chapter 2: NETWORK CABLING
PULLING CABLE
Two methods for pulling cable in LANs:
External installation
Internal installation
Focus on UTP cabling. Briefly describe the main characteristics of external and internal installations. Identify the advantages and disadvantages of each method.

29. EXTERNAL INSTALLATION PROCESS
Chapter 2: NETWORK CABLING
EXTERNAL INSTALLATION PROCESS
To successfully perform an external installation:
Identify the locations for computers and hubs.
Plan the cabling route.
Measure the route and leave some slack.
Buy prefabricated cables.
Lay cables out loosely without connecting or securing them.
Secure cables and avoid kinks.
Plug in the cables and turn on the hub or switch.
Describe and give examples of the external installation process.

30. A SIMPLE EXTERNAL INSTALLATION
Chapter 2: NETWORK CABLING
A SIMPLE EXTERNAL INSTALLATION
This installation uses prefabricated UTP cables run from each computer to a hub near where the equipment is located. Note that the installation does not require cabling through walls, ceilings, or floors. Note than an external installation is portable, not permanent. The drawback to an external installation is that cables are visible in the open, although you can make up for this by using raceways or cable fasteners.

31. SECURING EXTERNAL CABLES
Chapter 2: NETWORK CABLING
SECURING EXTERNAL CABLES
Secure and protect cabling by
Installing rubber cable protectors
Stapling cables to walls and doorways
Tying cables in place with plastic or fabric ties
Installing a raceway

32. RUBBER CABLE PROTECTOR
Chapter 2: NETWORK CABLING
RUBBER CABLE PROTECTOR

33. Chapter 2: NETWORK CABLING
CABLE STAPLING
Make sure students understand that a household staple gun and staples are not appropriate for this task.

34. Chapter 2: NETWORK CABLING
CABLE TIES

35. Chapter 2: NETWORK CABLING
RACEWAY

36. INTERNAL INSTALLATION COMPONENTS
Chapter 2: NETWORK CABLING
INTERNAL INSTALLATION COMPONENTS

37. INTERNAL INSTALLATION PROCESS
Chapter 2: NETWORK CABLING
INTERNAL INSTALLATION PROCESS
To successfully perform an internal installation:
Identify the locations for network devices, hub, and patch panels.
Plan the cabling route.
Label bulk cable runs, starting at the patch panel.
Pull cabling to the destination wall plate.
Secure cabling along the route.
Label cables at terminating wall plates.
Attach cabling connectors.
Connect cabling to network devices, hubs, and patch panels.
Describe and give examples of the internal installation process. Give students tips, like using coat hangers and balls of string to pull cables. Remind students not to exceed the distance limitations of the cabling they are installing. They must calculate the entire run from hub to node, including all obstacles. Exceeding distance limitations is generally not a factor when you are using prefabricated cables.

38. Chapter 2: NETWORK CABLING
CABLE PULLING TOOLS
Professional tools used to pull cable include
Cable puller
Telepole
Fish tape
Explain some of the innovative methods, such as coil and throw. Mention unconventional tools like coat hangers, a ball of string, a tennis ball, a collapsible fishing rod, any telescoping rod with a hook on the end, and any others you can think of.
Remind students to adhere to building and fire codes and to avoid electromagnetic interference (EMI) obstacles like fluorescent lights.

39. Chapter 2: NETWORK CABLING
CABLE PULLERS

40. Chapter 2: NETWORK CABLING
TELEPOLE

41. Chapter 2: NETWORK CABLING
FISH TAPE

42. STRAIGHT THROUGH AND CROSSOVER WIRING
Chapter 2: NETWORK CABLING
STRAIGHT THROUGH AND CROSSOVER WIRING
Wiring within a twisted pair cable is configured as either
Straight through, where each wire (or pin) is attached to the same contact point at each end
Crossover, where transmit contacts on each end of the cable are connected to the receive contact at the other end

43. STRAIGHT THROUGH WIRING
Chapter 2: NETWORK CABLING
STRAIGHT THROUGH WIRING
It’s important to explain that Universal Service Order Codes (USOC) standards apply strictly to telecommunication standards. Also make sure students understand that they should not use silver satin cables.

44. Chapter 2: NETWORK CABLING
CROSSOVER WIRING
Make sure students know the difference between crossover and straight through cable and when to use each.

45. Chapter 2: NETWORK CABLING
INTERNAL CABLING
Point out each physical link and specify whether it requires a straight through or crossover cable. Describe the link pulse signal, the autonegotiation process, and the purpose of the uplink port and light-emitting diodes (LEDs) on the hub. Also discuss the internal crossover circuit in the hub, and its function.

46. Chapter 2: NETWORK CABLING
PATCH PANEL
Patch panels are passive devices.

47. Chapter 2: NETWORK CABLING
THE PUNCH DOWN PROCESS
To punch down wiring:
Strip some of the insulating sheath off the cable end to expose the wires.
Separate the twisted-pair wires.
Strip a small amount of insulation off each wire.
Insert the wires into the contact points within the jack.
Press the bare wire down between the metal contacts.
Cut off excess wire.

48. Chapter 2: NETWORK CABLING
PUNCH DOWN WIRING
The process of securing wiring to an RJ-45 connector is called punching down, even though it uses a crimping tool. Note that for exam objective 4.5, students must be able to select the appropriate tool when they are given a wiring task. You might want to demonstrate how to use a crimping tool if you have one available.

49. Chapter 2: NETWORK CABLING
SUMMARY
The three basic LAN topologies are bus, star, and ring. WLANs are becoming more popular. Mesh networks are not typically used in LANs.
The primary cable types used in LANs are coaxial, twisted pair, and fiber optic.
External installations are best suited for small networks using prefabricated cable.
Internal installations are best suited for large networks using bulk cable, wall plates, patch panels, and hubs.
Professional cabling tools, such as telepoles, fish tape, cable pullers, punch down tools, and crimpers make complex installation projects easier.
Summarize the information presented in this chapter. Direct students to the questions at the end of the chapter.