SMU MBA ASSIGNMENTS

Answer : Fast Ethernet Technology Fast Ethernet, or 100BaseT, is conventional Ethernet but faster, operating at 100 Mbpsinstead of 10 Mbps. Fast Ethernet is based on the proven CSMA/CD Media Access Control (MAC) protocol and can use existing10BaseT cabling (See Appendix for pinot diagram and table). Data can move from 10Mbps to 100 Mbps without protocol translation or changes to application and networkingsoftware.Data- Link Layer Fast Ethernet maintains CSMA/CD, the Ethernet transmission protocol. 

However, Fast Ethernet reduces the duration of time each bit is transmitted by a factor of 10, enabling the packet speed to increase tenfold from 10 Mbps to 100 Mbps. Data can move between Ethernet and Fast Ethernet without requiring protocol translation, because Fast Ethernet also maintains the 10BaseT error control functions as well as the frame format andlength.Other high-speed technologies such as 100VG-AnyLAN, FDDI, and Asynchronous Transfer Mode (ATM) achieve 100 Mbpsor higher speeds by implementing different protocols that require protocol translation when moving data to and from 10BaseT. This protocol translation involves changes to the frame that typically mean higher latencies when frames are passed through layer 2 LAN switches.

Physical Layer Media Options Fast Ethernet can run over the same variety of media as 10BaseT, including UTP,shielded twisted-pair (STP), and beer. The Fast Ethernet specification dense separate physical sub layers for each media type:- 100BaseT4 for four pairs of voice- or data-grade Category 3, 4, and 5 UTP wiring- 100BaseTX for two pairs of data-grade Category 5 UTP and STP wiring- 100BaseFX for two strands of 62.5/125-micron multimode beer In many cases, organizations can upgrade to 100BaseT technology without replacing existing wiring. However, for installations with Category 3 UTP wiring in all or part of their locations, four pairs must be available to implement Fast Ethernet. The MII layer of 100BaseT couples these physical sub layers to the CSMA/CD MAC layer (see Figure 1). The MII provides a single interface that can support external transceivers for any of the 100BaseT physical sub layers. For the physical connection, theme is implemented on Fast Ethernet devices such as routers, switches, hubs, and adapters, and on transceiver devices using a 40-pin connector (See Appendix for pinoutand connector diagrams). Cisco Systems contributed to the MII specification.PublicCopyright © 1999 Cisco Systems, Inc. All Rights Reserved. Physical Layer Signalling Schemes Each physical sub layer uses a signalling scheme that is appropriate to its media type.100BaseT4 uses three pairs of wire for 100-Mbps transmission and the fourth pair for collision detection. This method lowers the 100BaseT4 signalling to 33 Mbps per pair, making it suitable for Category 3, 4, and 5 wiring.100BaseTX uses one pair of wires for transmission (125-MHz frequency operating at 80- percent efficiency to allow for 4B5B encoding) and the other pair for collision detection and receive. 100BaseFX uses one beer for transmission and the other beer for collision detection and receive. The 100BaseTX and 100BaseFX physical signalling channels are based on FDDI physical layers developed and approved by the American National.

Standards Institute (ANSI) X3T9.5 committee. 100BaseTX uses the MLT-3 line encoding signalling scheme, which Cisco developed and contributed to the ANSIcommittee as the specification for FDDI over Category 5 UTP. Today MLT-3 also issued as the signalling scheme for ATM over Category 5 UTP.Gigabit Ethernet: Gigabit Ethernet is a 1-gigabit/sec (1,000-Mbit/sec) extension of the IEEE 802.3 Ethernet networking standard. Its primary niches are corporate LANs, campus networks, and service provider networks where it can be used to tie together existing 10-Mbit/sec and100-Mbit/sec Ethernet networks. Gigabit Ethernet can replace 100-Mbit/sec FDDI (Fibber Distributed Data Interface) and Fast Ethernet backbones, and it competes with ATM(Asynchronous Transfer Mode) as a core networking technology. Many ISPs use Gigabit Ethernet in their data centers.Gigabit Ethernet provides an ideal upgrade path for existing Ethernet-based networks. It can be installed as a backbone network while retaining the existing investment in Ethernet hubs, switches, and wiring plants. In addition, management tools can be retained, although network analyzers will require updates to handle the higher speed. Gigabit Ethernet provides an alternative to ATM as a high-speed networking technology. While ATM has built-in Quos (quality of service) to support real-time network traffic, Gigabit Ethernet may be able to provide a high level of service quality by providing more bandwidth than is needed.

Gigabit Ethernet features and specification

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Gigabit Ethernet modes and functional elements

Gigabit Ethernet committees and specifications, including:

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1000Base-LX (IEEE 802.3z)

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1000Base-SX (IEEE 802.3z)

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1000Base-CX (IEEE 802.3z)

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1000Base-T (IEEE 802.3ab)

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10-Gigabit Ethernet (IEEE 802.3ae)

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Gigabit Ethernet switches

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Network configuration and design

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Flat network or subnets

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Gigabit Ethernet backbones

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Switch-to-server links

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Gigabit Ethernet to the desktop

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Switch-to-switch links

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Gigabit Ethernet versus ATM

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Hybrid Gigabit Ethernet/ATM Core Network

10-Gigabit Ethernet

As if 1 Grits/sec wasn’t enough, the IEEE is working to define 10-Gigabit Ethernet(sometimes called “10 GE”). The new standard is being developed by the IEEE 802.3aeWorking Group. Service providers will be the first to take advantage of this standard. It is being deployed in emerging metro-Ethernet networks. See “MAN (Metropolitan Area  Network)” and ” Network Access Services.”As with 1-Gigabit Ethernet, 10-Gigabit Ethernet will preserve the 802.3 Ethernet frame format, as well as minimum and maximum frame sizes. It will support full-duplex operation only. The topology is star-wired LANs that use point-to-point links, and structured cabling topologies. 802.3ad link aggregation will also be supported.

The new standard will support new multimedia applications, distributed processing, imaging, medical, CAD/CAM, and a variety of other applications-many that cannot even be perceived today. Most certainly it will be used in service provider data centres and as part of metropolitan area networks. The technology will also be useful in the SAN(Storage Area Network) environment. Refer to the following Web sites for more information.

 

Q.2 Differentiate the working between pure ALOHA and slotted ALOHA. [10 Marks]

 

Q.3 Write down distance vector algorithm. Explain path vector protocol. [10 Marks]

Q.4 State the working principle of TCP segment header and UDP header. [10 Marks]

Q.5 What is IP addressing? Discuss different classes of IP Addressing. [10 Marks]

Q.6 Define Cryptography. Discuss two cryptographic techniques. [10 Marks]