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
Token Ring - II• Data transfer is facilitated with the help of token passing mechanism
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
Token Ring - IV• Advantages: Disadvantages: – Data collision does not System collapses if occur links between nodes – Every station is allowed are malfunctioning to transmit data No alternative link to – Time required to carry transmit the data the amount of data can Data transmission is be calculated through single direction – Minimum cable Performance degrades requirement when junk data is transmitted
Token Ring Vs Ethernet Token Ring EthernetToken Ring network uses token passing Ethernet network use CSMA/CD mechanism. mechanism.Physical star topology is used. Any topology can be used as physical topology.Defined by IEEE 802.5 standard. Defined by IEEE 802.3 standard.Devices in token ring may transmit only at Devices can transmit as soon as the specific time. medium is free.Support heavy network traffic and The performance of the Ethernet network maintains the network performance. degrades as network traffic increases.Token Ring network is deterministic. Ethernet network is not deterministic as token ring.Token ring network provides bandwidth Ethernet network provides bandwidth efficiency up to 90%. efficiency up to 40%.The network setup and maintenance of The cost of network equipment is lower for token ring is expensive than Ethernet. Ethernet.
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
Token Ring Vs Token Bus Token Ring Token BusDesigned for offices. Designed for large factories.Star topology is used as physical topology. Bus topology is used as physical topology.A token is passed over the physical ring A virtual ring is formed over which the token itself. is passed.Defined by IEEE 802.5 standard. Defined by IEEE 802.4 standardIn Token ring the maximum time that a In Token Bus network the maximum time token will take to reach the end station that a token will take to reach the end can be calculated. station cannot be calculated.
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
Fiber Distributed Data Interface (FDDI)• Provides high performance and multiple stations networking• Widely used in Metropolitan Area network• Based on token ring architecture
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
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
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
Copper Distributed Data Interface (CDDI)• Version of FDDI• Uses twisted-pair copper cable instead of fiber optic cable• Supports 100 Mbps DTR and 100m segment length• Official name - Twisted-Pair Physical Medium-Dependent (TP-PMD)• Only two types of cables are supported by ANSI standard for CDDI: – 150 Ohm STP – CAT5 UTP
Signaling and Connection Standards• Ensure that equipments to be used for creating networks can work together Signaling Standards FDDI FOIRL 10Base - F
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• A high speed transfer technology for voice, video and data over public networks
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.
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
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
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
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
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• Cost effective solutionfor connecting local workgroups• Allows 32 active nodes within 300m area
ARCNET• Attached Resource Computer NETwork (ARCNET)• First LAN system introduced by Datapoint Corporation• Uses a Token Passing bus structure similar to Token Ring• 255 nodes per network and supports speed up to 20 Mbps• Supports segment length up to 600 meters• Still it is popular in robotics and industrial controls markets
ARCNET – Devices• Active Hub – Collection of 8 or 16 ports and use BNC female connectors for connecting devices. Isolates the port electrically• Passive Hub – Splits signals and consists of 4 ports• 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
ARCNET - Cables• Coaxial Cable – Uses RG62 coaxial cable• Unshielded Twisted Pair (UTP) – Uses RJ11 or RJ45 connectors and maximum segment length is 400m• Fiber Optic – Uses both SM and MM fibre cable
MAN• MAN connects different LANs• Cover large distances to function across city MAN Systems Switched Distributed Multimegabit Queue Data Dual Bus (DQDB) Service (SMDS)
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• Standard speed is 45 Mbps• Uses a connectionless service and less expensive as compared to leased line
SMDS Network Components• Provide high-speed data transmission service Network Components Customer Subscriber Premises Carrier Network Equipment Equipment Interface (CPE) (SNI)
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
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
Wireless LANs• Wireless networks enable the user to move around the house and use the computer.
Phone Line Networks - I• Phone line networks provide satisfactory performance at a much lower cost than wireless systems.
Phone Line Networks II• Carries data at the rate of 1 or 10 Mbps• Intel’s AnyPoint are used in this network• Computers are interconnected through parallel port
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