Review Media Connections and Collisions n Various networking

Review - Media, Connections, and Collisions n Various networking media u UTP, n STP, Coax, Fiber LAN media specifications/standards u TIA/EIA n Standards Ethernet u Layer 1 components u Collision domain n Network topologies 1

n What are five physical media used in networks? u STP, n UTP, Coax, Optical Fiber, and Wireless. What are the maximum length the cables? u STP: 100 m; UTP: 100 m; Coax: 500 m or 185 m; Fiber: 2 km. n What is the advantage of an STP cable? u Greater n protection from interference. What are the disadvantages of an STP cable? u Thick, expensive, hard to install. 2

n What are the advantages of a UTP cable? u Cheap, thin, easy to install, fastest copper-based medium. n What are the disadvantages of a UTP cable? u More n prone to noise, short unboosted run. What are the advantages of a Coaxial cable? u Relatively inexpensive, run unrepeated longer than UTP, better noise rejection characteristics. n What are the disadvantages of a Coaxial cable? u Thick, improper grounding will cause problems. 3

n What are the advantages of a Fiber-optic cable? u Longest unboosted run, does not transmit electricity, not susceptible to electromagnetic interference. n What are the disadvantages of a Fiber-optic cable? u Most n expensive medium, hard to handle. What is a feature of a Fiber-optic cable? u It is capable of higher data rates than other types of networking media. n Which cable is the most frequently recommended and installed? u Category 5 UTP cables. 4

n What are standards? u Sets of rules or procedures that are either widely used, or officially specified. n Standards ensure ______ between the various network devices. u compatibility n Name four organizations that issue standards for networking media! u IEEE, n and interoperability. UL, EIA, and TIA. Which organization(s) had the greatest impact on networking media standards? u EIA and TIA. 5

n Name two most widely used standards for technical performance of networking media! u TIA/EIA-568 -A n and TIA/EIA-569. List the maximum cable runs for horizontal cabling according to TIA/EIA-568 -A! u Horizontal cabling: 90 m; Patch cord at horizontal cross-conect: 6 m; Patch cord at work-area: 3 m. 6

n 10 Base. T uses _____ cable as standard. u UTP. n What does the twisting of the wires do in a Cat 5 UTP cable? u Limits signal degradation by “self-shielding” (cancellation). n Cat 5 UTP cables are terminated using _____. u RJ-45 n connectors. RJ-45 connectors has _____ conductors. u 8. 7

n A patch panel has _____ on one side, and _____ on the other side. u RJ-45 n jacks; punch-down blocks. What is one purpose of a repeater? u Extends n the physical length of a network segment. The networking term for a device that is the center of a star topology network is a _____. u hub. n A hub is also known as a _____. u Multi-port repeater. 8

n What is a collision? u. A problem situation that occurs when two bits (packets) propagate at the same time on the same network media. n What happens to data packets during a collision? u They n will be destroyed, bit by bit. What is a collision domain? u The area within the network where data packets originate and collide. n Name one characteristic of a collision domain! u All computers/hosts are on a single shared access media. 9

n What do repeaters (and hubs) do to a collision domain? u Repeaters (and hubs) extends the collision domain. n What does the “Four Repeater Rule” states? u No more than four repeaters or repeating hubs can be between any two computers on the network. n The Four Repeater Rule is also known as the ______. u The 5 -4 -3 -2 -1 Rule of Thumb. 10

n How many collision domains exist in a network containing one repeater AND one hub? u One. n What is the networking term for reducing the size of a collision domain by breaking it up into smaller domains? u Segmentation. n What networking devices are used for segmentation? u Bridges, switches, and routers. 11

n Name nine network topologies! u Bus, Ring, Dual Ring, Star, Extended Star, Hierarchical/Tree, Mesh/Full, Cellular, Irregular. n What is the difference between a physical topology and a logical topology? u. A physical topology describes the plan for wiring physical devices; A logical topology describes how information flows through a network. 12

n Describe the bus topology! u All of its nodes are connected directly to one physical link, and there is no other connection between nodes. n What is the advantage of bus topology? u (1) All hosts are connected to each other, and thus can communicate directly. (2) Every networking device can see all signals from all devices. n What is the disadvantage of bus topology? u. A break in the cable/physical link will disconnect hosts from each other. 13

n Describe the star topology! u Central node with all links to other nodes radiating from it. n What is the advantage of star topology? u (1) All nodes can communicate with each other, conveniently. (2) Security and restricted access reasons. n What is the disadvantage of star topology? u Needs lots of network media and the network would be susceptible to problems at central node. 14

n Describe the extended star topology! u LAN topology in which each of the end nodes of the core topology are acting as the center of its own star topology. n What is the advantage of extended star topology? u (1) Keeps wiring runs shorter. (2) Limits the number of devices that need to interconnect to a central node. 15

n What is a characteristic of mesh topology? u Every n node is linked directly to each other. What is a characteristic of cellular topology? u There are no physical links, only electromagnetic waves. n What is a characteristic of irregular topology? u No obvious patterns to the links and nodes. 16

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