1 / 67

Network Transmission Equipment

Network Transmission Equipment. Chapter 4. Learning Objectives. Describe the purpose of LAN network transmission equipment: NICs, repeaters, MAUs, hubs, bridges, routers, brouters, switches, and gateways Explain how LAN network equipment works. continued…. Learning Objectives.

varsha
Download Presentation

Network Transmission Equipment

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Network Transmission Equipment Chapter 4

  2. Learning Objectives • Describe the purpose of LAN network transmission equipment: • NICs, repeaters, MAUs, hubs, bridges, routers, brouters, switches, and gateways • Explain how LAN network equipment works continued…

  3. Learning Objectives • Describe the purpose of WAN network equipment: • Multiplexers, channel banks, private telephone networks, types of modems, ISDN adapters, access servers, and routers • Explain how WAN network equipment works

  4. NICs Repeaters MAUs Hubs Bridges Routers Brouters Switches Gateways LAN Transmission Equipment

  5. NIC • Enables network device to connect to network • Network connection requirements • Appropriate connector for network medium • Transceiver • Controller to support MAC sublayer of Data Link layer • Protocol control firmware

  6. A Combination NIC

  7. Role of MAC Controller Unit • Works with firmware to correctly encapsulate: • Source and destination address information • Data to be transported • CRC error control information

  8. Transport andTransmission Options • Transport options • Combined transport options make it easy to upgrade a network for high-speed communication • Transmissions options • Half-duplex transmissions • Full-duplex transmissions

  9. FDDI NICs • Connect host systems/file servers to FDDI network equipment using single attachment • Attach network equipment to FDDI cabling via dual attachment

  10. ATM NICs • Connect ATM switches or servers to an ATM network • Available to desktop • Relatively expensive

  11. Wireless NIC • Modes • Ad hoc peer-to-peer communication with another wireless NIC • Communication with an access point • Provide flexibility and convenience

  12. Buses and NICs • Industry Standard Architecture (ISA) • Extended Industry Standard Architecture (EISA) • Microchannel Architecture (MCA) • Peripheral Computer Interface (PCI) • SPARC Bus (SBUS) • NuBus • Universal Serial Bus (USB) • VESA local bus (VL-bus)

  13. Choosing a NIC • For host computer, server, or workstation? • Network media and network transport methods in use? • Manufacturer? • Computer or network equipment bus type? • Operating system used by the computer? • Use of half- or full-duplex communications? • How does it attach to network (for special application)?

  14. Repeater • Amplifies and retimes a packet or cell-carrying signal so that it can be sent along all outgoing cable segments attached to that repeater • Filters out signal disturbance or noise

  15. Repeaters Are Used to… • Extend cable segment • Increase number of nodes beyond limit of one segment • Sense network problem and shut down cable segment (partitioning) • Connect to components in other network devices continued…

  16. Repeaters Are Used to… • Connect segments that use different media • Extend backbone cable segments in LANs and WANs • Extend long, fiber-optic cable segments • Increase communications distance of T-carrier lines

  17. A Multiport Repeater

  18. Repeaters • Advantage • Inexpensive way to extend a network • Disadvantage • Can create excessive amount of network traffic

  19. Multistation Access Unit (MAU) • Central hub that links token ring nodes into a topology that physically resembles a star but in which data signals are transferred in a logical ring pattern

  20. MAUs Are Used to… • Connect workstations into a logical ring through physical star topology • Move token and frames around the ring • Amplify data signals • Connect in a daisy-chained manner to expand token ring network • Provide for orderly movement of data • Shut down ports to malfunctioning nodes

  21. MAUs • Passive hub • Active hub • Patch cables and lobe cables

  22. Ring In and Ring Out Ports

  23. Token Ring MAU Specifications

  24. Hub • Central network device used in star topology to join networks

  25. Hubs Are Used to… • Provide a central unit from which to connect multiple nodes into one network • Permit many computers to be connected on single or multiple LANs • Provide multiprotocol services • Consolidate network backbone • Provide connections for different media types • Enable centralized network management and design

  26. Types of Network Hubs • Unmanaged hubs • Dual-speed hubs • Workgroup hubs • Stackable hubs • Chassis hubs

  27. Bridge • Connects different LANs or LAN segments using the same access method • Operates in promiscuous mode; can look at frame addresses (unlike repeaters) • Operates at MAC sublayer of OSI Data Link layer • Protocol independent; only look at MAC address

  28. Bridges Are Used to… • Extend a LAN when maximum connection limit has been reached • Extend a LAN beyond the length limit • Segment LANs to reduce data traffic bottlenecks • Prevent unauthorized access to a LAN

  29. Bridged Network

  30. Bridge Functions • Learning • Filtering • Forwarding

  31. Cascade Bridging

  32. Advantages of Bridges • Limit traffic to certain network segments; enhance performance • Can use as a firewall to keep intruders out of a network

  33. Types of Bridges • Local bridge • Connects networks in close proximity • Can be used to segment a portion of a network to reduce heavy traffic problems • Remote bridge • Joins networks across the same city, between cities, and between states to create one network

  34. Bridge • Token ring source-route bridge • Incorporated into 802.5 token ring LAN specification • Performs routing at OSI Network layer • Spanning tree algorithm • Ensures that frames are not transmitted in an endless loop • Enables frames to be sent along most cost-effective network path

  35. Bridge Protocol Data Units (BPDUs) Frame Format

  36. Router • Connects networks having the same or different access methods and media • Forwards packets to networks by using decision-making process based on: • Routing table data • Discovery of most efficient routes • Preprogrammed information from network administrator • Connects LAN at Network layer of OSI model

  37. Routers Are Used to… • Efficiently direct packets from one network to another, reducing excessive traffic • Join neighboring or distant networks • Connect dissimilar networks • Prevent network bottlenecks by isolating portions of a network • Secure portions of a network from intruders

  38. Static and Dynamic Routing • Static routing • Controls routing decisions by network administrator through preset routing instructions • Dynamic routing • Constantly checks network configuration • Automatically updates routing tables • Makes decisions about how to route packets

  39. Routing Tables and Protocols • Routing tables • Contain addresses of other routers • Routing protocols • Routing Information Protocol (RIP) • Communicates entire contents of routing tables to other routers • Open Shortest Path First (OSPF) protocol • Communicates information about immediate links to other nodes

  40. Advantages of OSPF Protocol • Sends only the portion of routing table that pertains to its most immediate router links • Packages routing information in more compact format that RIP • Only updated routing table information is shared among routers, rather than the entire routing table

  41. Brouter • Acts as a bridge or a router, depending on how it is set up to forward a given protocol

  42. Brouters Are Used to… • Handle packets efficiently on a multiprotocol network that includes some protocols that can be routed and some that cannot • Isolate and direct network traffic to reduce congestion • Join networks • Secure a certain portion of a network by controlling who can access it

  43. Switch • Links network segments • Forwards and filters frames between segments • Provides bridging capacity and the ability to increase bandwidth on existing networks

  44. Switching Techniques • Cut-through switching • Store-and-forward switching (buffered switching)

  45. Gateway • Enables communications between two different types of networked systems

  46. Gateways Are Used to… • Convert commonly used protocols to a specialized protocol • Convert message formats • Translate different addressing schemes • Link a host computer to a LAN • Provide terminal emulation • Direct electronic mail to the right network destination • Connect networks with different architectures

  47. Gateway

More Related