1 Chapter 2: LAN Standards, Physical Connectivity, and Media Access.

Slides:



Advertisements
Similar presentations
Shape of a Network.
Advertisements

Network Hardware and Physical Media
Introduction to Network
Networks Terminology and Hardware. Network A network is a group of connected computers that can communicate with each other to share information and equipment,
Computer Networking (Appendix C) Objectives
1 Chapter 9 Computer Networks. 2 Chapter Topics OSI network layers Network Topology Media access control Addressing and routing Network hardware Network.
Telecommunications Chapter 5 Chapter 5 Telecommunications
1 LANs are Subnet Standards Only Physical and Data Link Layer standards Implemented by the NICs:NICs Application Transport Internet LAN Subnet (NIC) Application.
CMPE 80N - Introduction to Networks and the Internet 1 CMPE 80N Winter 2004 Lecture 8 Introduction to Networks and the Internet.
Ethernet: CSMA/CD (Carrier Sense Multiple Access with Collision Detection) Access method: method of controlling how network nodes access communications.
Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. McGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies,
Computer Network 實踐資管 Wang-Jiunn Cheng 2004 PART IV-1 Local Area Networks (LANs) Topology.
Understanding Networks II. Objectives Compare client and network operating systems Learn about local area network technologies, including Ethernet, Token.
Lesson 4 – UNDERSTANDING NETWORK CABLING. Network topologies Network cabling Installing and maintaining Network cabling Selecting and installing a SOHO.
1 LAN Topologies, Access methods (Week 1, Wednesday 1/10/2007) © Abdou Illia, Spring 2007.
Core 3: Communication Systems. On any network there are two types of computers present – servers and clients. By definition Client-Server architecture.
COMPUTER NETWORKS.
Topologies – A topologies is an arrange of cables in a LAN. The most common topologies are,star, ring, bus and also a hybrid that got all of the mixtures.
1 Computer Networks Course: CIS 3003 Fundamental of Information Technology.
Network Topologies An introduction to Network Topologies and the Link Layer.
Chapter 10 LAN Wiring, Physical Topology, and Interface Hardware Network Interface Card (fig 10.2)(fig 10.2) Ethernet wiring schemes – Thicknet – Thinnet.
The Ethernet Prepared by: Amer Al-Qadri Ahmad Abdul-Rahman Ismail khistah
Chapter 6 High-Speed LANs Chapter 6 High-Speed LANs.
Chapter 20 Networks. 4 Questions that need to be answered concerning networks? –How will each computer be identified? –What kind of wire should you run.
Hardware Concepts Chapter 4.
Network Design Essentials
Chapter 5 Networks Communicating and Sharing Resources
Computer Network: It is group of interconnected computers and devices which are sharing the same communication infrastructure and communication protocols.
Lecture 2 Computer Communications and Networks Boriana Koleva Room: C54 Phone:
NETWORK CABLING Chapter 2
Chapter 9A Network Basics.
Networking Technologies Here are a few of the big questions: How will each computer be identified? If two or more computers want to talk at the same time,
SIMS-201 Computer Networks. 2 Introduction to Computer Networks Chapter 19 The Local Area Network  Overview.
Networks LANS,. FastPoll True Questions Answer A for True and B for False A wireless infrastructure network uses a centralized broadcasting device, such.
ACM 511 Chapter 2. Communication Communicating the Messages The best approach is to divide the data into smaller, more manageable pieces to send over.
Introduction network Protocol
Network Technologies Chapter 2. Approaches to Network Communication Connection-Oriented –Circuit-switched –A dedicated connection (circuit) is formed.
Network Hardware and Software. What is a network? A network consists of two or more computers that are linked in order to: share resources (such as printers.
SYSTEM ADMINISTRATION Chapter 1 Logical and Physical Network Topologies.
CT1303 LAN LECTURE 15.
Access to Shared Media - Media Access Control protocols RD-CSY10171.
1 Data Link Layer Lecture 22 Imran Ahmed University of Management & Technology.
LANs No. 1  Seattle Pacific University Small Local Area Networks: Single Collision-Domain Networks Kevin Bolding Electrical Engineering Seattle Pacific.
Lecture 11 Network Basics. 2 Network Definition Set of technologies that connects computers –Hardware, software & media Allows users to –communicate and.
Day10 LAN. Why? Allow more than one machine to share –Resources –Internet connectivity –Information.
5 SECTION A 1 Network Building Blocks  Network Classifications  LAN Standards  Network Devices  Clients, Servers, and Peers  Physical Topology  Network.
IST 126 Computer Networks Day 2. Server Security Only one password needed to access network Associated with the account is permission to access certain.
Networking Topology 1.BUS Topology 2.RING Topology 3.STAR Topology
CSC 116 – Computer Networks Fall 2015 Instructor: Robert Spengler.
Business Data Communications, Fourth Edition Chapter 9: Local Area Networks.
Lesson 4—Networking BASICS1 Networking BASICS Network Architectures Unit 2 Lesson 4.
IEEE 802.X Standards The Institute of Electrical and Electronics Engineers (IEEE) has developed a series of networking standards to ensure that networking.
 Describe the basic and hybrid LAN physical topologies and their uses, advantages, and disadvantages  Describe the backbone structures that form the.
Shape of a Network 10/10/07. Topology  The way the computers are cabled together  Four different layouts  Logical topology describes the way data travels.
Simple LAN Topologies  Terminators stop signals after they have reached their destination  Signal bounce –Phenomenon in which signals travel endlessly.
NETWORK. To connect a computer with a network we need NETWORK ADAPTER.
Local Area Networks: Topologies. 2 Packet Identification & MAC Addresses Each packet specifies an intended recipient with an identifier. – Demultiplexing.
COMPUTER NETWORKS Lecture-8 Husnain Sherazi. Review Lecture 7  Shared Communication Channel  Locality of Reference Principle  LAN Topologies – Star.
© 2015 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 1 Chapter 7: Networking Concepts IT Essentials v6.0.
Chapter 4: Network Access
SIMS-201 Computer Networks.
Network Protocols.
Local Area Networks: Topologies
Introduction to Computers
Introduction To Computers
Chapter 4: Network Access
Guide to Networking Essentials, 6th Edition
SIMS-201 Computer Networks.
SYSTEM ADMINISTRATION Chapter 3
Presentation transcript:

1 Chapter 2: LAN Standards, Physical Connectivity, and Media Access

2 LAN Standards Standards are required so that different manufacturers can create equipment that will interoperate without special configuration. Standards groups include: ISO. International Organization for Standardization establishes standards for networking operation. ANSI. American National Standards Institute is the US representative to ISO. EIA/TIA. Electronics Industries Alliance/Telecommunications Industry Association is an industry based standards group. IEEE. Institute of Electrical and Electronics Engineers is an international professional organization that sets communications standards. IEEE Project 802 sets standards for cabling and data transmission on local area networks.

3 Physical Connectivity Network Interface Card (NIC). Also known as Network Card or Ethernet Adapter. Transmits and receives signals to the LAN. Computers can not communicate on LAN without this device. Each Network Card has a Media Access Control (MAC) address. This is also known as the physical address or Ethernet address. MAC address is a unique 12 digit hexadecimal number that is hard coded into each network interface. The first half of a MAC address is the manufacturer’s ID. The second half a serial number. -F3-1C-D4 Serial number AC Manufacturer ID

4 Cable and Wireless Physical cabling is also known as bounded media. Transmissions are bound to the physical media. To communicate, hosts must be physically connected to that media. Physical cabling is usually located in a building’s plenum. Wireless network is known as unbounded media. Transmissions are not bound to a physical cable. To communicate, hosts do not need to be physically connected.

5 Coaxial Cable Coaxial cable is often used in older LANs. Known as RG58, Thinnet, and 10Base2. Maximum bandwidth of 10 Mbps. Maximum segment length of 185 meters (605 feet). Maximum of 30 hosts per segment.

6 Coaxial Cable Hosts on an RG58 network require a network card with an RG58 adapter. To add the host to the network, the cable section must have an RG58 connector on both ends with a “T” piece fitted between them. Both ends of the segment should be terminated using a a piece of equipment known as a terminator. A terminator stops signals on the network echoing back when they reach the end of the segment.

7 Twisted Pair Cable The most common cabling technology in use today. Consists of four pairs of copper wires twisted around each other. Twists are used because they reduce interference. Maximum length: 100 meters (328 feet). Maximum bandwidth: 1000 Mbps.

8 Twisted Pair Cable Connect to networking devices such as network interface cards and switches using RJ45 connectors. One end must connect to a host, the other to a networking device such as a switch. You can only connect two computers together if you use a crossover cable, which uses different wiring.

9 Fiber Optic Cable Fiber optic cable has better data security than twisted pair or RG58. You can’t intercept the signals without breaking the cable. Fiber optic cable is immune to electromagnetic interference, something that can cause problems for twisted pair or RG58. The disadvantages of fiber optic cable is that it is very expensive and that it is not very flexible. Bend it too far and it will break the core, rendering the cable useless. Fiber optic cable is mostly use as a backbone to connect LANs together, rather than connecting hosts together on a LAN.

10 Wireless Wireless networks do not require physical infrastructure like cables. Wireless networks have short range. Wireless networks have limited bandwidth. Transmissions can be intercepted easily by a person outside building with a wireless access device.

11 LAN Topologies Physical topology is the actual location and arrangement of physical connections between devices on the network. Logical topology is the path that a given datagram travels between two devices. Often there is more than one way to get from one host to another.

12 Bus Topology All network devices connected to a common cable in logical linear fashion. Transmissions are sent along the length of the bus segment. Adding hosts to the network requires breaking the network. Failure of one host can cause failure of network.

13 Star Topology Connection from each device to a central location, usually a switch. Most commonly used physical topology. Failure of one cable does not bring down network.

14 Ring Topology Network is connected in an endless loop. No termination required. Uncommon topology today, more common in 1980s.

15 CSMA/CD Stands for Carrier Sense Multiple Access with Collision Detection. Each device listens to media for transmissions. When media is clear, initiates transmission and listens for collision. If collision occurs, device waits for random amount of time before attempting transmission again. Commonly used on physical networks. Wait for network silence Wait for network silence Begin Transmission COLLISION! Wait random amount of time Wait random amount of time Begin Transmission

16 CSMA/CA Stands for Carrier Sense Multiple Access with Collision Avoidance. Each device listens to media for transmissions. When media is clear, device sends an intent to transmit signal. As this signal is small, chances of collision are minimized. Used often in wireless networking. Wait for network silence Signal Intent to Transmit

17 Summary Standards are set by industry, professional and government organizations to ensure that devices can interoperate. NICs have MAC addresses and are needed to communicate with other devices on the LAN. RG58 cable has a maximum bandwidth of 10 Mbps and is found in older LANs. Twisted pair is commonly used today and connects using an RG58 connector. Star Topologies are most commonly used today. A switch often sits at the center of a star topology. CSMA/CD transmits and then listens to see if there was a collision. CSMA/CA sends an intent to transmit message.

18 Discussion Questions  What is the difference between a physical and a logical network?  What is the difference between a bus and a star topology?  Which media access method sends an intent to transmit signal?  What are the benefits of using twisted pair over RG58?  What is a MAC address?