Multistation access units maus
Sponsored Links
This presentation is the property of its rightful owner.
1 / 53

Multistation Access Units (MAUs) PowerPoint PPT Presentation

  • Uploaded on
  • Presentation posted in: General

Multistation Access Units (MAUs). Connect workstations in a logical ring through a physical star topology Move the token and packets around the ring Amplify data signals Connect in a daisy-chained manner to expand a token ring network Provide orderly movement of data.

Download Presentation

Multistation Access Units (MAUs)

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

Multistation Access Units (MAUs)

  • Connect workstations in a logical ring through a physical star topology

  • Move the token and packets around the ring

  • Amplify data signals

  • Connect in a daisy-chained manner to expand a token ring network

  • Provide orderly movement of data

Multistation Access Units (MAUs)

  • A passive hub connects nodes in a star topology, performing no signal enhance-ment as the packet moves from one node to the next through the hub.

  • An active hub connects nodes in a star topology, regenerating, retiming, and amplifying the data signal each time it passes through the hub.

Ring-in (RI) connection

Ring-out (RO) connection


MAU with Eight Connections

Type 6 patch cable





Type 6 patch cable



MAUs Connected Using the RI and RO Ports

To Draw the Network Diagram

  • Drawing the token ring network in Microsoft Paint


  • A multiplexer is a switch that divides a communication medium into multiple channels so several nodes can communicate at the same time.

  • A signal that is multiplexed must be demultiplexed at the other end.



  • Work at the OSI physical level, switching from channel to channel using one of three physical methods:

    • Time division multiple access (TDMA)

    • Frequency division multiple access (FDMA)

    • Statistical multiple access


  • TDMA enables multiple devices to communi-cate over the same communications medium by creating time slots in which each device transmits.

  • FDMA creates separate channels on one communication medium by establishing different frequencies for each channel.

  • Statistical multiple access multiplexing allocates the communication resources according to what is needed for the task.


  • A repeater amplifies and retimes a packet-carrying signal so it can be sent along all cable segments.

  • As used in this context, a segment of cable is one cable run within the IEEE specifications.

How Repeaters Are Used

  • To extend a cable segment

  • To increase the number of nodes beyond the limit of one segment

  • To sense a problem and shut down a cable segment

  • To amplify and retime a signal (as a component in other network devices)

Research lab

Research lab


President’s office

Business office

Using a Repeaterto Extend a Network


  • An attached unit interface (AUI) connects coax or fiber-optic backbone cable to a network node, such as a repeater.

  • A partitioned segment is one that has been shut down because a portion of the segment is malfunctioning.

To Diagram the Interoffice Network

  • Microsoft Paint diagram of two rooms connected by a repeater


  • A bridge is a network device that connects different LAN segments using the same access method.

How Bridges Are Used

  • To extend a LAN when the maximum connection limit has been reached

  • To extend a LAN beyond the length limit

  • To segment LANs to reduce data traffic bottlenecks

  • To prevent unauthorized access to LAN (for security)


Bridged Network


  • A network device that operates in promiscuous mode reads frame destination address information before sending a packet onto other connected segments of the network.

Types of Bridges

  • A local bridge connects networks in close proximity and is used to segment a portion of a network to reduce problems caused by heavy traffic.

  • A remote bridge joins networks across the same city, between cities, and between states to create one network.

Important Functions of a Bridge

  • Learning

  • Filtering

  • Forwarding


Bridge A


Bridge B


Cascaded Network Segments

Token Ring Bridging

  • Token ring bridges use source routing to forward packets on the network.

  • Hops are the number of times a packet travels point-to-point from one network to the next.

Source route bridging


  • A router connects networks having the same or different access methods.

  • It forwards packets to networks by using a decision-making process based on:

    • Routing table data

    • Discovery of the most efficient routes

    • Preprogrammed information from the network administrator

How Routers Are Used

  • To efficiently direct packets from one network to another, reducing excessive traffic

  • To join neighboring or distant networks

  • To connect dissimilar networks

  • To prevent network bottlenecks by isolating portions of a network

  • To secure portions of a network from intruders

A Router Forwarding a Frame to the Right Network

Static and Dynamic Routing

  • Static routing involves control of routing decisions by the network administrator through preset routing instructions.

  • In dynamic routing, the router constantly:

    • Checks the network configuration

    • Automatically updates routing tables

    • Makes its own decisions about how to route frames

Routing Tables and Protocols

  • Routers maintain information about node addresses and network status in databases.

    • The routing table database contains the addresses of other routers and each end node.

  • Routers regularly exchange information about network traffic, the network topology, and the status of network lines.

  • Routers exchange information by using one or more routing protocols.

Local and Remote Routers

  • A local router joins networks in the same building or between buildings in close proximity.

  • A firewall is software and/or hardware employed to restrict who has access to a network, to specific network segments, or to certain network resources (such as servers).

  • A remote router joins networks across large geographical areas, such as between cities, states, and countries.

A Local Router Connecting Networks in Adjacent Buildings

Business building

Manufacturing building



  • A brouter, also called a multiprotocol router, is a network device that acts like a bridge or a router, depending on how it is set up to forward a given protocol.

  • It is used on networks that operate with several different protocols.

How Brouters Are Used

  • For efficient packet handling on a multiprotocol network with some protocols that can be routed and some that cannot

  • To isolate and direct network traffic to reduce congestion

  • To join networks

  • To secure a certain portion of a network by controlling who can access it


  • A hub is a central network device that connects network devices in a star topology.

  • It is also referred to as a concentrator (or switch), which is a device that can have multiple inputs and outputs all active at one time.

Services Offered by Hubs

  • Provide a central unit from which to connect multiple nodes into one network

  • Permit large numbers of computers to be connected on single or multiple LANs

  • Reduce network congestion through centralizing network design

  • Provide multiprotocol services

Types of Hubs

  • MAUs

  • 10BASE-T hubs

  • 100BASE-X hubs

  • Intelligent and modular hubs

10BASE-T Hubs

  • One of the simplest hubs

  • Popular way to connect workgroups on small and large LANs

  • Uses physical star topology to connect PCs to the central hub

  • Additional hubs are added by connecting one hub to the next.

Switching Hubs

  • Permit significant increase in the throughput capability of an existing 4 Mbps, 10 Mbps, or 16 Mbps network by taking full advantage of exiting bandwidth capabilities

  • Allow an existing network to be separated into multiple smaller segments, each independent of the others

  • Can be installed on LANs in a WAN where specific LANs are experiencing increased network traffic

100BASE-X Hubs

  • Multimedia, video, and GUI client/server applications have fostered the need for high-bandwidth, high-speed technologies.

Intelligent and Modular Hubs

  • An intelligent hub has network management and performance monitoring capabilities.

  • A modular hub, also called a chassis hub, contains a backplane into which different modules can be inserted.

  • A backplane is the main circuit board in modular equipment, containing slots as plug-ins for modular cards. It provides connections between the modular boards, a power source, and grounding.

To Diagram 10BASE-T Star Topology on Two Floors

  • Network diagram of 10BASE-T network segments connected to an intelligent hub


  • A gateway enables communications between two different types of networked systems, such as between complex protocols or between different e-mail systems.

How Gateways Are Used

  • To convert commonly used protocols to a specialized protocol

  • To convert message formats from one format to another

  • To translate different addressing schemes

  • To link a host computer to a LAN


How Gateways Are Used

  • To provide terminal emulation for connections to a host computer

  • To direct e-mail to the right network destination

  • To connect networks with different architectures

Systems Network Architecture (SNA)

  • SNA is a layered communications protocol used by IBM for communications between IBM mainframe computers and terminals.

  • It employs seven-layered communications that are similar to the OSI model, but there are differences in the way the services are grouped within the layers.

SNA gateway

IBM/Mainframe Connected through an SNA Gateway

ATM Switches

  • An ATM switch determines the network channel used to transmit an ATM cell received from a node, taking into account the type of information in the cell (voice, video, data) and the transmission speed needed.

Capabilities of ATM Switches

  • Provide high-speed communications on a network backbone

  • Provide cell transmissions directly to the desktop

  • Enable high-speed communication between network hubs

  • Centralize network design for better management


Capabilities of ATM Switches

  • Connect to very high speed networks, such as SONET

  • Enable network design around workgroup members at dissimilar locations (virtual LANs)

  • Reduce network bottlenecks through high-speed communications and efficient traffic management through workgroups

ATM switch

ATM Switch

Virtual LANs (VLANs)

  • A virtual LAN (VLAN) uses switches, routers, and internetworking software to configure a network into subnetworks of logical workgroups, independent of the physical network topology.

Advantages of VLANs

  • VLANs enable a network to operate at the most efficient level; it is not limited by physical topology.

  • Network resources can be managed based on the actual work groupings of users.

  • VLANs can be reconfigured to move a user from an old workgroup to new one.

VLAN Workgroups through ATM Switching

ATM switch

ATM switch

Central ATM switch

Networking Devices and the OSI Model

  • Login