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Other Network Architecture. Chapter 6. Chapter Objectives - I. Explain token ring topology Explain token bus topology Differentiate between token ring, token bus and Ethernet Explain FDDI Describe signaling and connection standards. Chapter Objectives - II. Understand ATM
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Other NetworkArchitecture Chapter 6
Chapter Objectives - I • Explain token ring topology • Explain token bus topology • Differentiate between token ring, token bus and Ethernet • Explain FDDI • Describe signaling and connection standards Chapter 6
Chapter Objectives - II • Understand ATM • Explain AppleTalk • Explain ARCNET • Explain MAN systems, SMDS and DQDB • Describe Ethernet alternatives Chapter 6
Recall • 10Base-T is the most commonly used Ethernet standard, which provide transmission speed up to 10 Mbps. • The 5-4-3 rule is designed for the number of repeaters and segments on shared access. • High speed Ethernet standards are: • Fast Ethernet (100Base Ethernet) • Gigabit Ethernet • 10-Gigabit Ethernet Chapter 6
Token Ring - I • Token Ring is a network architecture developed by IBM • Also known as IEEE 802.5 • Uses logical ring topology • Multiple MAUs can be connected to extend the ring Chapter 6
Token Ring - II • Data transfer is facilitated with the help of token passing mechanism Chapter 6
Token Ring - III • Speed is either 4 or 16 Mbps • Performance is significantly faster than Ethernet networks • Uses physical star topology • Hides logical ring inside a hub, known as Multistation Access Unit (MAU) • Unshielded Twisted Pair (UTP) or Shielded Twisted Pair (STP) cables are used connect nodes to the hub Chapter 6
Token Ring - IV • Advantages: • Data collision does not occur • Every station is allowed to transmit data • Time required to carry the amount of data can be calculated • Minimum cable requirement • Disadvantages: • System collapses if links between nodes are malfunctioning • No alternative link to transmit the data • Data transmission is through single direction • Performance degrades when junk data is transmitted Chapter 6
Token Ring Vs Ethernet Chapter 6
Token Bus • Defined by IEEE 802.4 • Uses bus topology as physical topology • Token passing mechanism is used for data transfer like token ring • Token is passed over a virtual ring within network Chapter 6
Token Ring Vs Token Bus Chapter 6
Fiber LAN • Uses different types of fiber optic cables for interconnection • Types of Fast Ethernet standards which use fiber optic cables: • 100BASE-FX – Uses two filaments of multi-mode optical fiber cable. Maximum cable length is 400m • 100BASE-SX – Uses two filaments of multi-mode optical fiber cable. Maximum cable length is 300m • 100BASE-BX – Uses single-mode fiber optic cable • FDDI – Supports 100 Mbps data rate over fiber optic cables Chapter 6
Fiber Distributed Data Interface(FDDI) • Provides high performance and multiple stations networking • Widely used in Metropolitan Area network • Based on token ring architecture Chapter 6
FDDI – Network Model • FDDI stations: • Single–Attached Station – Connected through a single connector called S-port • Dual–Attached Station – Connected through A-port and B-port • FDDI concentrators: • Single–Attached Concentrator – Connected to the FDDI network through a single connector • Dual–Attached Concentrator – Connected to the FDDI network through A-port and B-port Chapter 6
FDDI – Devices • The connectors used in FDDI are unique • Every FDDI device requires two connectors to support two rings • Using fiber optic cabling, FDDI segments could reach up to two kilometers between systems, with a maximum ring size of 100 kilometers Chapter 6
FDDI – Failure Recovery • Wrapping Process – Modify the structure of the network to recover from failure • Recovers network connectivity on failure of FDDI station • Recovers network connectivity on failure of cables between any two FDDI stations • Optical Bypass switch – Maintain the network connectivity by providing an optical connection that bypasses the failed station Chapter 6
Copper Distributed Data Interface (CDDI) • Version of FDDI • Uses twisted-pair copper cable instead of fiber optic cable • Official name - Twisted-Pair Physical Medium-Dependent (TP-PMD) • Only two types of cables are supported by ANSI standard for CDDI: • STP • UTP Chapter 6
Signaling and Connection Standards • Ensure that equipments to be used for creating networks can work together Chapter 6
Case Study The accounts department of Money Maker Bank in Mumbai is integrated using FDDI technology. One of the computers have become non functional and a segment of cable has worn out. The computer needs to be isolated from the network and the connectivity of the network needs to be maintained. Chapter 6
Problem Unable to identify failure recovery method Chapter 6
Suggested Solution Use of optical bypass switches is needed to isolate the computer from the network. The cable fault can be rectified with wrapping. Chapter 6
Asynchronous Transfer Mode (ATM) • Network protocol which converts the data traffic into stream of fixed size cell before transmission • Designed to transfer data simultaneously from multiple sources • Can be employed in both LAN and WAN environments • Can provide a maximum data speed of 622 Mbps Chapter 6
ATM – Protocol Reference Model • ATM protocol reference model describes the functions of different types of layers and organizational units that act on data when it is transmitted using ATM technology. Chapter 6
ATM – Performance • Throughput – Rate at which ATM cells depart from the ATM switch • Connection Blocking Probability – Defines the probability of Non-availability of enough resources for generating physical connections between inlet and outlet • Cell Loss Probability – Defines a no. of data cell that can be handled by a switch queue • Switching Delay – Time required for cell to pass through the ATM switch • Cell Delay Variation – Probability that the switching delay of the ATM switch exceeds the certain value Chapter 6
AppleTalk • AppleTalk protocol suite was developed by Apple Computers for use on Macintosh computers • Developed to allow the multiple users to share resources • AppleTalk protocol suite is also compatible with Ethernet, Token Ring and FDDI network architectures • AppleTalk is an early implementation of distributed client-server networking system Chapter 6
AppleTalk – Network Components • Sockets – Location in AppleTalk node which is recognized by a unique address • Nodes – Device which is a part of an AppleTalk network e.g. computer, printer or router • Networks – Consists of a cable with multiple nodes connected to the cable • Zones – Constitutes a group of nodes and network which are logically associated Chapter 6
AppleTalk – Network Address • AppleTalk uses addressing to identify and recognize every device on a network similar to other common protocols • Address is broadcast to all other nodes to determine whether it has been already utilized • Fields in AppleTalk network address: • Network number • Node number • Socket number Chapter 6
LocalTalk • LocalTalk is obsolete but its relation to Appletalk, a popular piece of networking software is found on every Apple brand computer • Supported by AppleTalk network protocol for Macintosh computers • Implemented at the data link-layer • Uses network bus topology Chapter 6
ARCNET • Attached Resource Computer NETwork (ARCNET) • First LAN system introduced by Datapoint Corporation • Uses a Token Passing bus structure similar to Token Ring • Logical structure is always a bus • 255 nodes per network and supports speed up to 20 Mbps • supports segment lengths up to 600 meters Chapter 6
ARCNET – Devices • Active Hub – Splits and amplifies the signal, isolates the port electrically • Passive Hub – Splits signals • ARCNET Card - Different types of network interface card (NIC) can be used depending upon the type of network topology • BNC Terminator – Prevent signal reflection in network Chapter 6
ARCNET - Cables • Coaxial Cable – Inexpensive and provide high propagation factor • Unshielded Twisted Pair (UTP) – Twisted pair cables are easy to terminate • Fiber Optic – Lower propagation factor than coaxial cable Chapter 6
MAN • MAN connects different LANs • Cover large distances to function across city Chapter 6
Switched Multimegabit Data Service (SMDS) • High speed packet-switched MAN technology used for communication over public data networks (PDNs) • SMDS is the first broadband service that was provided to the public • Packets transferred are of variable length and contains the source and destination address • Allows the packets to flow from one LAN to another • Standard speed is 45 Mbps Chapter 6
SMDS Network Components • Provide high-speed data transmission service Chapter 6
SMDS Interface Protocol (SIP) • Connectionless service • Used for communication between CPE and SMDS carrier equipment • Based on IEEE 802.6 Distributed Queue Dual Bus (DQDB) standards • Consists of three levels: • SIP Level 3 • SIP Level 2 • SIP Level 1 Chapter 6
IEEE 802.6 Standard • Mainly developed for MANs • Uses the Distributed Queue Dual Bus (DQDB) network form • DQDB is Data-link layer communication protocol • Used for data, voice and video transmission based on cell switching technology • DQDB can cover distance up to 30 miles and supports transfer rate ranging from 34 Mbps to 154 Mbps • DQDB consists of two unidirectional buses Chapter 6
Alternatives to Ethernet • Sometimes it is impossible to run Ethernet cabling so “no new wire” networking technologies can be used • In alternatives to Ethernet two or more computers can be connected into a LAN without running a wire • Three networking technologies are: • Wireless LANs • Phone line networks • Power line networks Chapter 6
Wireless LANs • Wireless networks enable the user to move around the house and use the computer. Chapter 6
Phone Line Networks • Phone line networks provide satisfactory performance at a much lower cost than wireless systems. Chapter 6
Power Line Networks • Power Line Networks are attached to the PC through parallel port and by using existing wiring to carry networking data • Use radio signals which are easily affected by interference • Offer performance of 350 Kbps Chapter 6
Summary - I • The network arrangement and data communication is given by logical topology • Token ring and token bus are the two logical topologies • A token passing mechanism is used in both token ring and token bus • 100Base-FX, 100 Base SX and 100BaseBX and FDDI are types of fiber LAN • Single-attached station (SAS) and Dual-attached station (DAS) are the different types of FDDI stations • SAS is connected to the FDDI network through a single connector called S-port Chapter 6
Summary - II • Asynchronous Transfer Mode (ATM) network protocol converts data into a stream of fixed size cell before transmission • Apple Computers has designed a protocol suite known as AppleTalk • The network components of AppleTalk are sockets, nodes, network and zones • Attached Resource Computer NETwork (ARCNET), the first LAN system and supports up to 255 nodes • The different types of devices used in ARCnet are, active hub, passive hub, ARCnet card and BNC terminator Chapter 6
Summary - III • The most prominently used type of cabling for ARCnet are, coaxial cables, UTP and fiber optic • Point-to-point, distributed star, bus, daisy chain are the different topologies which are suitable for ARCnet • MAN uses Switched Multimegabit Data Service (SMDS) and Distributed Queue Dual Bus (DQDB) systems • SMDS is a connectionless, high speed packet-switched technology used for communication over public networks • DQDB is a Data-link layer communication protocol • IEEE 802.6 standard uses DQDB network form • The Ethernet alternatives are, Wireless LANs, Phone line networks and Power line networks Chapter 6