CISCO NETWORKING ACADEMY PROGRAM CCNA 1 AND 2 LAB COMPANION

30 years ago by Robert Metcalfe and his coworkers at Xerox. The first Ethernet standard was published by a consortium of Digital Equipment Company, Intel, and Xerox (DIX) in 1980. Metcalfe wanted Ethernet to be a shared standard from which everyone could benefit. Therefore, DIX made the[r]

and EIA-530 WAN serial connection options.Several types of physical connections enable you to connect to serial WAN services. You must select the correct serial cable type to use with the router, depending on the physi-cal implementation that you choose or the physical implementation that you[r]

propagation delay A simple measurement of how long it takes for a signal to travel along the cable being tested.PSELFEXT (power sum equal-level far-end crosstalk (PSELFEXT) The combined effect of ELFEXT from all wire pairs.PSNEXT (power sum near-end crosstalk) Measures the cumulative effect of NEXT[r]

History and Evolution of Ethernet 259source device sends data out on a network, the data carries the MAC address of its intended destination. As this data propagates along the network medium, the NIC in each device on the network checks to see if its MAC address matches the physical des-tinat[r]

Ethernet Operation 269Figure 5-10 CSMA/CDNetworking devices are capable of detecting when a collision has occurred because the amplitude of the signal on the networking media increases (CD = collision detect). When a collision occurs, each device that is transmitting continues to transmit dat[r]

NICs.chpt_04.fm Page 222 Tuesday, May 27, 2003 9:01 AMLAN Connection Devices 223computer to another without a permanent cable connection. Wireless signals are elec-tromagnetic waves that travel through the air. No physical medium is necessary for wireless signals, making them a very versatile way to[r]

and determine where a cable terminates. You also verify PC NIC functionality.chpt_04.fm Page 201 Tuesday, May 27, 2003 9:01 AM202 Chapter 4: Cable Testing and Cabling LANs and WANsOther Test ParametersThe combination of the effects of signal attenuation and impedance disc[r]

■ STP cable combines the techniques of shielding, cancellation, and twisting of wires. ScTP cable is essentially a twisted pair wrapped in a metallic foil shield.■ UTP cable is a four-pair wire medium used in a variety of networks.■ Coaxial cable consists of four main parts: copper conductor,[r]

D. Spread spectrum creates little interference.1102.book Page 179 Tuesday, May 20, 2003 2:53 PM180 Chapter 3: Networking Media19. Which statement does not describe the features of direct-sequence spread spectrum (DSSS)?A. DSSS is reliable because each bit is represented by a string of[r]

275 m (853 feet) for 62.5 micro fiber; 550 m (1804.5 feet) for 50 micro fiberStar SC1000BASE-LX62.5/50 micro multimode fiber; 9-micron single-mode fiber440 m (1443.6 feet) for 62.5 micro fiber; 550 m (1804.5 feet) for 50 micro fiber; 3 to 10 km (1.86 to 6.2 miles) on single-mode fiberStar SCchpt_04.fm Page[r]

Ethernet Operation 279reach Station 1, it also truncates the current transmission and substitutes a 32-bit jam signal in place of the remainder of the frame being transmitted. Upon sending the 32-bit jam signal, Station 1 ceases all transmissions.A jam signal can be composed of[r]

Burst limit —*Interframe spacing stretch ratio 104 bits**** 10-Gbps Ethernet does not permit half-duplex operation, so parameters related to slot timing and collision handling do not apply.** The value listed is the official interframe spacing.*** The interframe spacing stretch ratio applies e[r]

signal between 2.)Figure 6-12 100BASE-TX Signal SampleDuring the initial process of establishing synchronization with the link partner to establish a link, the receiver circuit expects to see only 4B/5B idle code groups.The cable pinout for a 100BASE-TX connection is identical to the one for[r]

Gigabit, 10-Gb, and Future Ethernet 339Bit patterns from the MAC sublayer are converted into symbols, with symbols some-times controlling information (such as start frame, end frame, and medium idle condi-tions). The entire frame is broken up into control symbols and data symbol[r]

Ethernet Switching 359Figure 6-30 Transmitting Data to a Known StationThe original transmission indicated where that MAC address came from, enabling the switch to deliver traffic in the network more efficiently. MicrosegmentationAs technology improved, it became possible to build bridges with more cap[r]

Key Terms 369cut-through switching A packet-switching approach that streams data through a switch so that the leading edge of a packet exits the switch at the output port before the packet finishes entering the input port. A device using cut-through packet switch-ing reads, processes, and forw[r]

3 devices, as well as how data must be encapsulated to effectively make that journey. Remember that data is encapsulated at the network layer with an IP source and destina-tion address, and at the data link layer with a MAC source and destination address. The basic rule to follo[r]

Ethernet Operation 289first hears an FLP burst or some other signaling scheme. In the silent listening state, a portable computer is capable of conserving enough battery power to be quite worth-while, although this mode is not supported by the standard.Ethernet Duplex OperationTwo duplex modes exist:[r]