Teaching Tip: The introduction to Chapter 6 runs beyond the cover page and includes the first two figures. This is a nice transition from the previous chapters, filled with facts to this chapter, also fact-filled, but packed with details on installing and troubleshooting a physical network. Inform the students that they will go beyond the neat and tidy “real-world” network shown in Figure 6.2 to inside telecommunications rooms, walls, and ceilings.
Teaching Tip While the Historical/Conceptual information is less than two pages, extending to the middle of Page 99, the first paragraph on Page 98 explains the scope of the CompTIA Network+ exam regarding designing and installing network cabling and other components. The hands-on ability to actually run cabling is more than is expected on the exam, but it will certainly give students a deeper understanding.
Teaching Tip Be sure to point out the Tech Tip on page 98, The Big Wireless Lie . Students new to networking may embrace the notion that wireless is the future and is more important than wired and they may have already asked questions about wireless at this point. This Tech Tip puts it in its place – for now. The significance (or lack) of wireless is reflected by how little of the Network+ objective list includes wireless topics. Assure students that they will learn about wireless networking in Chapter 16.
Teaching Tip If there is time, review the TIA/EIA 568 standards, per the Cross Check at the top of Page 99 before moving into the Test Specific content of the chapter. Also point out that students can explore the BICSI certifications (www.bicsi.org), as described in the Tech Tip on that page
Teaching Tip The Test Specific content begins here.
Teaching Tip Point out the fourth paragraph on Page 106 which explains that the TIA/EIA 568 specification only allows UTP cable lengths of 90 meters, although the standards for UTP previously studied have a maximum length of 100 meters. Make sure they understand that the “missing” 10 meters is to allow for the length added by the patch cables—both in the equipment room and in the work area.
Teaching Tip Summarize the section on Installing Structured Cabling by using the last paragraph on Page 121. This chapter does not prepare students for the highly skilled tasks required for installing structured cabling themselves. Rather, helps them gain an understanding of the process of installing structured cabling in order to work with most problems that come up in an installed structured cabling system.
Teaching Tip Discuss how to tell the difference between NICs because they look the same in some instances. The textbook does a good job of demonstrating this.
Teaching Tip Don’t overlook the BIOS Setup utility when troubleshooting a built-in NIC. Check to see that an onboard NIC is enabled. If it is enabled, then check for signs of failure. Seeing a lit indicator light on the port does not necessarily mean it is working. Dig around in the BIOS if the NIC is enabled, but does not appear to be working. Some BIOSs have an error log that may have captured the failure of the NIC. This confirms that you need to install a bus NIC in the computer to replace the failed built-in NIC.
Teaching Tip There is more than one way to detect the source of a problem. Point out the great real-world scenario on the bottom of page 128, in which they discovered that the manager of a building was turning off the power overnight. To detect this, they placed a voltage event recorder on a power outlet to track voltage over time. While it is a real cool use of a voltage event recorder, it is not the only way to discover that the server was shutting down every night. This is where a network tech needs to know a little secret about server operating systems: they all have log files. The network tech could have asked the server administrator to check out the log files on the server reporting that it was unable to connect to the Internet. Assuming there was no smart UPS to kick in with battery power, and communicate with the server when the power went off to initiate a controlled shutdown of the server, the System event log file would have shown no activity after the point in time when the power went off. The System event log file would have shown the server starting up in the morning, at which point an entry would have indicated that the last shutdown was abnormal (loss of power). That information alone may have been enough evidence that the power was turned off at night.
Networking Chapter 6
Installing a Physical Network Chapter 6
Objectives• Recognize and describe the functions of basic components in a structured cabling system• Explain the process of installing structured cable• Install a network interface card• Perform basic troubleshooting on a structured cable network
• Set of TIA/EIA standards• Details on every aspect of cabled network – Type of cabling – Position of wall outlets – And more…
• Goal – Create a safe, reliable cabling infrastructure• Applies to – Networks – Telephone – Video – Anything that needs low-power, distributed cabling
• Three important issues – Cable basics – Network Components – Assessment of connections leading outside the network
• Cable Basics – A Star is Born – Most basic network • A switch • UTP cable • Some PCs
Figure 6.3 A switch connected by UTP cable to two PCs
• Problems in keeping it simple (a switch in middle of office space) – Exposed cables are vulnerable to physical damage – Signals exposed to electrical interference – Limits ability to make changes to network
• Better installation design – Provides safety – Provides hardware to organize and protect cabling• Flexibility of cabling standard allows for growth• Solution: TIA/EIA standards for structured cabling
• Structured Cable Network Components – Telecommunications room – Horizontal cabling – Work area
• Horizontal cabling – From work area to telecommunications room – CAT5e or better – Solid core • Better conductor than stranded core • Will break if mishandled – Stranded core • Not as good a conductor • Stands up to handling without breaking
• Horizontal cabling – Number of Strands – Four-pair UTP assumed – High-end telephone setups use 25- or 100-pair
• Choosing Your Horizontal Cabling – CAT 5e or CAT 6 UTP – CAT 6a for 10GBaseT – Install higher-rated cable for future technologies – Contract network installers will bid with intention of installing lowest grade possible
• The Telecommunications Room – Heart of basic star – Intermediate distribution frame (IDF) – Endpoint of all horizontal runs from all work areas – Central component is equipment rack
• Equipment Rack – Safe, stable platform for hardware components – Network equipment comes rack-mounted – 19 inches wide – Varies in height • U = 1.75” • 1U, 2U, 4U
• Patch Panel box (continued) – Label cable connections on panel • Use a simple labeling scheme • TIA/EIA 606 is confusing – Wide variety of configurations • UTP, STP, or fiber ports • 8, 12, 24, 48, or more ports • UTP patch panels come with UTP ratings
• Cables – Connect patch cables to ports on front of panel • Short (two to five feet) • Premade UTP offer benefits – Stranded rather than solid cable – Different colors to help organize – Reinforced (booted) connector
• Work Area – Wall outlet • Female jack with CAT rating to accept cabling • Mounting plate, and faceplate – Connect PC to wall outlet with patch cable – Work area is source of most network failures
Figure 6.22 Typical home network interface box
• Structured Cable – Beyond the Star (cont.) – Typical building-wide network • High-speed backbone runs vertically • Backbone connects to multispeed switch on each floor • Dedicated telephone cabling backbone runs alongside • Demarc (demarcation point)
• More on Demarcs – Connection to outside world – Dividing line of responsibility – Network interface unit (NIU) • DSL or cable modem serves as a demarc in a home • Smart jack in NIU enables remote testing
• Structured Cable – Beyond the Star (cont.) – Connections inside the demarc • Network and telephone cables connect to demarc extension – Multiplexer for telephones – LAN switch for a network » Connects to a main patch panel—a vertical cross-connect
• Structured Cable – Beyond the Star (cont.) – Main distribution frame (MDF) • Another name for telecommunications room
• Getting a Floor Plan – Key to proper planning – Determine potential locations for telecommunications rooms – Locate physical firewalls – Gives an overall feel for scope of job – If no floor plan, create one
• Mapping the Runs – Determine the length of cable runs – Determine the route of cable runs – Determine location of each cable drop
• Mapping the Runs (cont.) – Talk to users, management, etc. • Determine future plans • Add extra drops – Begin to determine cost – Decide if cable runs will be inside or outside wall • Raceways install outside walls
• Pulling Cable (cont.) – Good cable management important for fast networks – Follow local codes, TIA/EIA, and NEC – Vertical drops most difficult – Install a low-voltage mounting bracket to hold faceplate – Use cable guides to help organize equipment closet
• Rolling Your Own Patch Cables – Use stranded UTP cable matching CAT level of horizontal runs – Use special crimp for stranded cable • RJ-45 crimper with built-in stripper • Pair of wire snips • Follow great instructions on Page 114 in Chapter 6
• Test the Cable Runs – Verify each cable run can handle network speed – Advanced network testing tools are $5,000- $10,000 – Lower-end tools work for basic network testing • Length of cable • Broken wires • Location of break • Wires terminated in correct place • Locate electrical or radio interference • Test for crosstalk
• Tools to use – Cable tester • Verifies cable and terminated ends are correct • Low-end are continuity testers • Better testers run wire map test to pick up shorts, crossed wires, etc. • Multimeter tests continuity
Figure 6.51 A typical cable certifier – a Microtest OMNIScanner (photo courtesy of Fluke Networks)
• Testing Fiber – Termination process is more involved • Stripping, polishing end of tiny fiber cable, gluing, inserting connector • Requires lots of tools and skill – Problems both like and unlike those of UTP cabling • Fiber does not experience crosstalk • Fiber does break – test with optical time domain reflectometer (OTDR)
• Testing Fiber (cont.) – TIA/EIA has complex requirements for testing fiber runs – Fiber certifiers test for • Attenuation – diffusion of light distance • Light leakage – occurs when fiber is bent too much • Modal distortion – unique to multimode fiber-optic cable
Figure 6.53 An optical time domain reflectometer (photo courtesy of Fluke Networks)
Figure 6.54 Light leakage – note the colored glow at the bends but the dark cable at the straight
tudents for the highly skilled tasks required for installing structured cabling themselves. Rather, helps them gain an understanding of the NICs
• Recognize different types of NICs on sight• Know how to install and troubleshoot NICs
• UTP Ethernet NICs – All use RJ-45 connector – Cable runs from NIC to hub or switch
• Fiber-optic NICs – Come in a wide variety – Multiple standards use same connector types – Must see documentation to determine what standard card supports
• Buying NICs – Recommend name-brand NICS • 3Com or Intel – Better made – Easy to replace missing driver – Recommend multispeed NICs – Stick with same model for all systems
• Physical Connections – Physically install the NIC – Many computers have built-in NICs
• Physical Connections (cont.) – Expansion Slots • Peripheral Component Interconnect (PCI) • PCI Express (PCIe) – PCIe x1 and PCIe x2 • USB – Convenient – Limited to max speed of 480 Mbps – Carry one in toolkit to test for failed NIC • PC Card only on laptops
• Drivers – Insert driver CD when prompted – OS may have a driver, but CD has extras – Verify driver install • Windows Device Manager • Linux Administration menu Network applet • Macintosh System Preferences Network utility
Figure 6.56 Typical fiber NIC (photo courtesy of 3Com Corp.)
• Link Lights – UTP NICs have LEDs for state of link – One to four link lights per card – Lights give clues about what’s happening – Check link lights when troubleshooting – Many fiber-optic NICs don’t have lights
• Diagnostics and Repair of Physical Cabling – Diagnosing Physical Problems (in order) • Remove software network issues – If one application fails, try another • Resolve hardware issues – “No server is found” error – No computers visible in Network app in Windows – Multiple systems failing to access the network
• Diagnostics and Repair of Physical Cabling – Check your lights (if available) – Check the NIC itself – Look for network status icon in the Notification Area in Windows – Check for failed switch
• Diagnostics and Repair of Physical Cabling – Check shared resources (servers) – Visually check cabling – Plug system into a known good outlet • If this works, suspect structured cabling running from drop to switch • Confirm with continuity test
• Diagnostics and Repair of Physical Cabling – Check the NIC • Detect bad NIC with operating system utility • Use available NIC diagnostic software • Loopback test on NIC – Internal only checks circuitry – External (with loopback plug) tests connector
• Diagnostics and Repair of Physical Cabling – Cable Testing • Most problems occur at the work area • After eliminating work area problems, go deeper • Use a time domain reflectometer (TDR) • Check problems in telecommunications room – Start at one end, placing stickers to track progress – Power concerns – Temperature concerns
Figure 6.67 An excellent voltage event recorder (photo courtesy of Fluke Networks)
• Diagnostics and Repair of Physical Cabling – Cable Testing • Toners – Trace cable runs – Two separate devices » Tone generator » Tone probe – Fox and Hound by Triplett Corporation – Advanced toners include phone jacks for communication