1 / 39

CIS 153 Networking Essentials

CIS 153 Networking Essentials Week 3 – Chapter 3 From last week A few of you are not turning in your quizzes online Student success form Read the book! Article Reviews Select an article from a computer journal or magazine about Networking

betty_james
Download Presentation

CIS 153 Networking Essentials

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CIS 153Networking Essentials Week 3 – Chapter 3

  2. From last week • A few of you are not turning in your quizzes online • Student success form • Read the book!

  3. Article Reviews • Select an article from a computer journal or magazine about Networking • Topics listed are just to give you ideas – there are certainly more possibilities • Written report should be one to two pages (please attach article with report or include link.) • Must present orally for 3-5 minutes • Be ready for questions

  4. What is… • Ad-Hoc and Infrastructure Mode? • Access Point? • What does a client do? • What does a server do?

  5. Chapter 3 – Networking Media • Bandwidth Rating - Cables can only carry a limited amount of information at a time • Common bandwidth ratings are Category 3, Category 5, Category 6 (higher the better) • Maximum segment length (attenuation) – Can only carry a signal so far • Like how DSL is distance limited

  6. General Cable Characteristics • Maximum number of segments per network (latency) – If you have too many routers and switches between end points the network will become slow or unusable (timeout) // Minimize hops • Interference – Avoid placing cable near interference sources (motors, transformers, fluorescent lights, and other electrical activity) • Many cable types are shielded to some extent • Twisted Pair

  7. General Cable Characteristics • Plenium-rated – Whether the plastic cladding is fire-rated to be placed in an office’s false ceiling • Otherwise conduit is needed • Bend radius – How far you can bend a cable before you break it • Especially problematic for fiber-optic and coax

  8. Baseband - Broadband • A baseband signal uses the entire wire to transmit or receive • One way at a time (half-duplex) • How most LAN’s work • In broadband multiple channels are modulated onto one wire • How most broadband internet works

  9. Baseband - Broadband

  10. Cable Types • Twisted Pair • Individual insulated copper wires are twisted to protect the signals from interference • Unshilded twisted pair (UTP) just has the twists in it • Prone to crosstalk • Shielded twisted pair (STP) has an extra foil shield between the wires and the external sheath

  11. Shielded and Unshielded Twisted-Pair

  12. Common sights in Twisted Pair Installations • Cables use RJ-45 plugs • Patch panels are often used in wiring closets to organize wiring • See table 3-1 on p.83

  13. Making Twisted-Pair cable connections • Wire cutters • Wire stripper • Crimp tool • RJ-45 plugs

  14. Side A – Side B

  15. Fiber optic • Virtually immune to electronic eavesdropping • Extremely high bandwidth (up to 200Gbps) • Extremely long runs (miles) • Each light conducting core can only send signals in one direction • Cables contain multiple strands-each of those strands are within an inner sheath • Usually all of those are combined within an outer sheath (or jacket)

  16. Notice it does not bend well

  17. Fiber Optic connectors • Multiple connector types are available for Fiber-optic • Straight tip (ST) – used most often in backbone Ethernet networks • ST locks onto the jack when twisted • Straight connection (SC) – Push on one piece component (has a notch to ensure correct orientation) • easy to install, less space for attachment, can be used when splicing

  18. Fiber Optic connectors • Locking Connection (LC) – push on and pull off using a latching mechanism similar to RJ-45. Half the size of SC • Medium interface connector (MIC) – Used in FDDI, one piece • Mechanical transfer registered jack (MT-RJ) – looks similar to RJ, high density, two fiber in one jack, ease of installation

  19. Fiber Optic installation • Fiber is still more difficult to install, but much easier than it used to be • Becoming almost as easy as copper • Now being used almost exclusively for backbone connections

  20. Single or Multimode? • Single-mode fiber optic cables • Only one glass fiber at the core • Cost more • Works with laser-based emitters • Used for long distances • Multimode fiber optic cables • Two or more glass fibers at the core • Cost less • Works with LED’s (light emitting diode) • Shorter distance

  21. Which should I choose? • Some ways to sort out which cable technologies to use • Bandwidth – How much do you need? • Budget – How much do you have? • Capacity – How much traffic? • You may want to separate the light and medium users from the heavy network users • You will want to separate your backbone traffic from your local traffic

  22. Which should I choose? • Environmental considerations • An environment that is electrically noisy or requires high data security will likely dictate fiber above other considerations • Placement – How will you get the cables there? • With more difficult cable runs TP or wireless becomes more desirable • Distance • Local building and fire codes • Existing cable plant

  23. Which should I choose? • Where money is no object and speed or long distance is greatly needed • Fiber • Where quick, cheap, and easy cable based networking • Unshielded Twisted Pair (UTP) • Combination Fiber/UPT • Fiber backbone and unshielded twisted pair to switches and devices • Mobility is king or wiring is difficult • Wireless

  24. Structured Cabling • Structured cabling is cabling organized in a logical and tidy manner • Usually include: • Work area (where computer is) • Horizontal wiring (run from wall jack to telco closet) • Telecommunications Closet • Connects to computer equipment in nearby area (in smaller networks also the entrance facility and sometimes the equipment room)

  25. Structured Cabling • Equipment rooms – where the servers and other major network equipment resides • May be main cross-connect for backbone cabling for the entire network • Might connect backbone between buildings • Backbone cabling (vertical cabling) • interconnects telco closets and equipment rooms. • Usually fiber but UTP ok if less than 90m

  26. Structured Cabling • Entrance Facility – LAN meets world

  27. Wireless • What’s it good for? • Temporary connections to existing wired networks • Backup connectivity to existing wired networks • Extend the network beyond the bounds wire or fiber in existing buildings • Allow mobility • See p.93

  28. How wireless networks operate

  29. Wireless characteristics • Quick note: an access point connects both wired and wireless networks. It does not have to be a router. • Higher frequency = lower distance • Higher frequency = higher bandwidth • Higher frequency technologies often use tight beam broadcasts and require line of sight

  30. Wireless technologies • Infrared – usually to sync PDA’s with computers or print to printers • Not used often except in specialized situations • Laser – used between buildings • Susceptible to rain fade • Line of sight (good and bad) • Narrowband (single-frequency) radio • Spread-spectrum – frequency hopping

  31. Wi-fi • 802.11b – 11Mbps • Most commonly found • 802.11g – 54Mbps • Most common higher speed system • 802.11a – 54Mbps • Lives at 5Ghz (less interference) • More expensive • Not very common • MIMO – 108Mbps • Soon to be 802.11n • Backwards compatible with b and g

  32. Wireless bridges • Connects two offices • Uses laser or broadcast technologies • You own the equipment not the telco • This type is unregulated (no FCC fee)

  33. WiMax 802.16 (Wireless MAN) • Two versions – fixed and mobile • Envisioned to provide Internet access without needing the cable or phone companies • Can deliver up to 70Mbps up to 30 miles • More likely speeds for an individual subscriber would be similar to current broadband and at a distance of approximately 10 miles

  34. WiMax 802.16 (Wireless MAN) • Fixed is here now • Mobile can not transmit as far as fixed can • Mobile allows roaming • Mobile became a standard about 9 months ago • Intel wants to integrate WiMax mobile in laptops (get internet access across vast geographic areas) • Sprint wants to implement it nationwide

  35. Microwave • Microwave • Higher transmission rates • Requires FCC approval • 5.8 GHz unlicensed • Expensive • Line of sight

  36. Microwave • Microwave can be terrestrial (land based) or satellite • Terrestrial can span contenental distances through relay towers • These relay towers are often placed on mountain tops • Across sparse areas this can be cheaper than laying wire • Satellite aims high at a geosynchronous satellite (22,300 Miles above earth) • Can have a latency of half a second between request and response

  37. Hands-On Exercises • In groups • Hands-On Project 3-3, 3-5, 3-6

More Related