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  • Show Introduction Discuss the importance of having a good understanding of basic networking and the concepts evolving around a network.
  • The term topology, or more specifically, network topology, refers to the arrangement or physical layout of computers, cables, and other components on the network. Topology, is the standard term that most network professionals use when they refer to the network's basic design. Developing a sense of how the different topologies are used is one key to understanding the capabilities of the different types of networks. Computers have to be connected in order to share resources or perform other communication tasks. Most networks use cable to connect one computer to another. However, it is not as simple as just plugging a computer into a cable connecting other computers. Different types of cable, combined with different network cards, network operating systems, and other components require different types of arrangements. A network's topology implies a number of conditions. For example, a particular topology can determine not only the type of cable used but how the cabling is run through floors, ceilings, and walls. Topology can also determine how computers communicate on the network. Different topologies require different communication methods, and these methods have a great influence on the network.
  • The shape of a local-area network (LAN) or other communications system. There are three principal topologies used in LANs. Bus Topology: All devices are connected to a central cable, called the bus or backbone . Bus networks are relatively inexpensive and easy to install for small networks. Ethernet systems use a bus topology. Ring Topology : All devices are connected to one another in the shape of a closed loop, so that each device is connected directly to two other devices, one on either side of it. Ring topologies are relatively expensive and difficult to install, but they offer high bandwidth and can span large distances. Star Topology: All devices are connected to a central hub . Star networks are relatively easy to install and manage, but bottlenecks can occur because all data must pass through the hub. These topologies can also be mixed. For example, a bus-star network consists of a high-bandwidth bus, called the backbone, which connects a collections of slower-bandwidth star segments.
  • In a star topology each computer or computers have their own cable segment. With most HUB’s this allows for independent operation. ****************************************
  • This network that we have been working on in this class is both a network and a LAN. LANs’ can be rather large as well. Give an example of the 35th Signal Brigade Headquarters. Network - A group of two or more computer systems linked together. Local Area Network - A computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. Each node (individual computer ) in a LAN has its own CPU with which it executes programs , but it is also able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printers , as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions.
  • This network that we have been working on in this class is both a network and a LAN. LANs’ can be rather large as well. Give an example of the 35th Signal Brigade Headquarters. Network - A group of two or more computer systems linked together. Local Area Network - A computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. Each node (individual computer ) in a LAN has its own CPU with which it executes programs , but it is also able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printers , as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions.
  • This network that we have been working on in this class is both a network and a LAN. LANs’ can be rather large as well. Give an example of the 35th Signal Brigade Headquarters. Network - A group of two or more computer systems linked together. Local Area Network - A computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. Each node (individual computer ) in a LAN has its own CPU with which it executes programs , but it is also able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printers , as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions.
  • An example of a WAN is a network that would handle an entire state or in our case the entire 18th Airborne Corps ************************************************* Explain the concept: To effectively manage and ensure successful completion of packets being sent a heirachy is established to route traffic from one location to another. LAN example: If you had a letter to mail and it was addressed to your neighbor, you would probably deliver it yourself. MAN example: If that letter had to go across town you would mail it. It would then go through Fayettevilles’ post office to be delivered. WAN example: If the address was destined to go from the east coast to the west coast it would be sent to a postal service headquarters, (Memphis) possibly another HUB before arriving on the west coast. WAN Networking uses similar process to deliver packets. The only difference is we use what is called a router to perform this function. It is much faster and more accurate. Metropolitan Area Network - a data network designed for a town or city. In terms of geographic breadth, MANs are larger than local-area networks (LANs) , but smaller than wide-area networks ( WANs ) . MANs are usually characterized by very high-speed connections using fiber optical cable or other digital media. Wide Area Network - A computer network that spans a relatively large geographical area. Typically, a WAN consists of two or more local-area networks (LANs) . Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites. The largest WAN in existence is the Internet . Hub - A common connection point for devices in a network . Hubs are commonly used to connect segments of a LAN . A hub contains multiple ports . When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets. Routers - A device that connects any number of LANs . Routers use headers and a forwarding table to determine where packets go, and they use ICMP to communicate with each other and configure the best route between any two hosts.
  • The IEEE 802.3 includes different signaling modes, media types, physical topologies, and data rates. Speed represents the number of megabits that can be transmitted over the standard in a second. Type defines the data signaling method , such as BASE for baseband and BROAD for broadband. Length is the maximum length of any segment given in hundredths of meters. The Ethernet specification served as the basis for the IEEE 802.3 standard , which specifies the physical and lower software layers. Ethernet uses the CSMA/CD access method to handle simultaneous demands. It is one of the most widely implemented LAN standards. Carrier Sense Multiple Access / Collision Detection - a set of rules determining how network devices respond when two devices attempt to use a data channel simultaneously (called a collision ). Standard Ethernet networks use CSMA/CD. This standard enables devices to detect a collision. After detecting a collision, a device waits a random delay time and then attempts to re-transmit the message. If the device detects a collision again, it waits twice as long to try to re-transmit the message. This is known as exponential back off.
  • This network that we have been working on in this class is both a network and a LAN. LANs’ can be rather large as well. Give an example of the 35th Signal Brigade Headquarters. Network - A group of two or more computer systems linked together. Local Area Network - A computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. Each node (individual computer ) in a LAN has its own CPU with which it executes programs , but it is also able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printers , as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions.
  • Backbone - Another term for bus , the main wire that connects nodes . The term is often used to describe the main network connections composing the Internet . Node - a processing location. A node can be a computer or some other device , such as a printer .
  • An example of a WAN is a network that would handle an entire state or in our case the entire 18th Airborne Corps ************************************************* Explain the concept: To effectively manage and ensure successful completion of packets being sent a heirachy is established to route traffic from one location to another. LAN example: If you had a letter to mail and it was addressed to your neighbor, you would probably deliver it yourself. MAN example: If that letter had to go across town you would mail it. It would then go through Fayettevilles’ post office to be delivered. WAN example: If the address was destined to go from the east coast to the west coast it would be sent to a postal service headquarters, (Memphis) possibly another HUB before arriving on the west coast. WAN Networking uses similar process to deliver packets. The only difference is we use what is called a router to perform this function. It is much faster and more accurate. Metropolitan Area Network - a data network designed for a town or city. In terms of geographic breadth, MANs are larger than local-area networks (LANs) , but smaller than wide-area networks ( WANs ) . MANs are usually characterized by very high-speed connections using fiber optical cable or other digital media. Wide Area Network - A computer network that spans a relatively large geographical area. Typically, a WAN consists of two or more local-area networks (LANs) . Computers connected to a wide-area network are often connected through public networks, such as the telephone system. They can also be connected through leased lines or satellites. The largest WAN in existence is the Internet . Hub - A common connection point for devices in a network . Hubs are commonly used to connect segments of a LAN . A hub contains multiple ports . When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets. Routers - A device that connects any number of LANs . Routers use headers and a forwarding table to determine where packets go, and they use ICMP to communicate with each other and configure the best route between any two hosts.
  • SIGNAL TRANSMISSION
  • Attenuation - The reduction of signal strength as a result of the capacitance, resistance, impedance, and other wire characteristics. Cross Talk - Whenever you send a current through a wire, the current creates a magnetic field around the wire. Nearby wires will absorb some of that field, which creates a reverse current. The current leaks from one pair of wires to another.
  • Consists of a central conductor surrounded by a physical jacket. This offers security, reliability, and speed. It is ideal for LANs, but distance limitations can be a problem for WANs. We’ll discuss four types of bound media: 1. Coaxial 2. Unshielded Twisted Pair - UTP 3. Shielded Twisted Pair - STP 4. Fiber Optics
  • Coaxial Cable - A type of wire that consists of a center wire surrounded by insulation and then a grounded shield of braided wire. The shield minimizes electrical and radio frequency interference. Coaxial cabling is the primary type of cabling used by the cable television industry and is also widely used for computer networks . Although more expensive than standard telephone wire, it is much less susceptible to interference and can carry much more data . Because the cable television industry has already connected millions of homes with coaxial cable, many analysts believe that they are the best positioned to capitalize on the much-heralded information highway . A form of baseband coaxial cable is RG-58. RG-58 is a 50-ohm cable used for Thin Ethernet LANs. Baseband Transmission - A type of digital data transmission in which each medium (wire) carries only one signal, or channel , at a time. In contrast, broadband transmission enables a single wire to carry multiple signals simultaneously. A form of broadband coaxial cable is RG-59. RG-59 is a 75-ohm cable used for cable TV. Broadband Transmission - A type of data transmission in which a single medium (wire) can carry several channels at once. Cable TV, for example, uses broadband transmission. In contrast, baseband transmission allows only one signal at a time.
  • A. Conducting core wire surrounded by insulation and braided metal shield and rubber, Teflon, or plastic shield outside B. Add foil shield around metal for double shielded C. Core can be copper(U) or stranded (AU) D. The shields protect from electrical noise and cross talk E. More resistant to interference and attenuation than twisted pair F. Attentuation is the loss of signal strength over distance G. Good choice for longer distance and higher data rates with low end hardware H. Transmit data, voice, and video Two types of coaxial cable: 1. Thin (thinnet) - The 10Base-2 standard (also called Thinnet ) uses 50 ohm coaxial cable (RG-58 A/U) with maximum lengths of 185 meters. This cable is thinner and more flexible than that used for the 10Base-5 standard. The RG-58 A/U cable is both less expensive and easier to place. 2. Thick(thicknet) - The original cabling standard for Ethernet that uses coaxial cables . The name derives from the fact that the maximum data transfer speed is 10 Mbps , it uses base band transmission , and the maximum length of cables is 5 00 meters. 10Base5 is also called thick Ethernet, ThickWire, and ThickNet.
  • RG-58 is the most popular coaxial cable in networking, because it is relatively low in cost. RG-58 is used in a Bus Topology and has a data rate of 10Mbps. It offers better immunity to Electromagnetic Interferance (EMI) than does twisted-pair, and it’s also relatively easy to install. RG-58 is also called thinnet and is about .25 inches thick; connects directly to the Nic(Network Interface Card). Network Interface Card - Often abbreviated as NIC, an expansion board you insert into a computer so the computer can be connected to a network . Most NICs are designed for a particular type of network, protocol , and media , although some can serve multiple networks. There are three types of end connectors that can be used for RG-58: 1. Compression 2. Crimp on 3. Screw on Connectors are the weakest link of a network
  • BNC Connectors: Used by thicknet and thinnet British Naval Connector or Bayonet Nut Connector or Bayonet Neill Concelman - a type of connector used with coaxial cables such as the RG-58 A/U cable used with the 10Base-2 Ethernet system . The basic BNC connector is mounted at each end of a cable. This connector has a center pin connected to the center cable conductor and a metal tube connected to the outer cable shield. A rotating ring outside the tube locks the cable to any receiving type connector. BNC T-connectors (used with the 10Base-2 system) are devices for connecting two cables to a network interface card (NIC) . A BNC barrel connector allows connecting two cables together. BNC connectors can also be used to connect some monitors , which increases the accuracy of the signals sent from the video adapter . Terminator - A device attached to the end-points of a bus network or daisy-chain . The purpose of the terminator is to absorb signals so that they do not reflect back down the line. Ethernet networks require a terminator at both ends of the bus, and SCSI chains require a single terminator at the end of the chain.
  • Thicknet uses a transciever to connect it to a drop cable Transceiver (transmitter-receiver) - a device that both transmits and receives analog or digital signals. The term is used most frequently to describe the component in local-area networks (LANs) that actually applies signals onto the network wire and detects signals passing through the wire. For many LANs, the transceiver is built into the network interface card (NIC) . Some types of networks, however, require an external transceiver. In Ethernet networks, a transceiver is also called a Medium Access Unit (MAU). Vampire tap connects the transceiver to the thicknet core Digital/Intel/Xerox (DIX) connector equivalent to AUI port connector and DB-15 connector. Attachment Unit Interface - the portion of the Ethernet standard that specifies how a cable is to be connected to an Ethernet card. AUI specifies a coaxial cable connected to a transceiver that plugs into a 15-pin socket on the network interface card (NIC) . Thicknet is expensive and hard to work with, but carries signal farther 1. Thin (thinnet) - The 10Base-2 standard (also called Thinnet ) uses 50 ohm coaxial cable (RG-58 A/U) with maximum lengths of 185 meters. This cable is thinner and more flexible than that used for the 10Base-5 standard. The RG-58 A/U cable is both less expensive and easier to place. 2. Thick(thicknet) - The original cabling standard for Ethernet that uses coaxial cables . The name derives from the fact that the maximum data transfer speed is 10 Mbps , it uses base band transmission , and the maximum length of cables is 5 00 meters. 10Base5 is also called thick Ethernet, ThickWire, and ThickNet.
  • Twisted Pair Cable - A type of cable that consists of two independently insulated wires twisted around one another. One wire carries the signal while the other wire is grounded and absorbs signal interference. Twisted-pair cable is used by older telephone networks and is the least expensive type of local-area network (LAN) cable. A. Two copper-insulated strands twisted to cancel electrical noise from adjacent pairs. B. If a pair has a shield, then it’s called a shielded twisted pair. C. Relatively easy to install. D. Unshielded twisted pair: Most widely used form of this cable.
  • Cat 1: Voice, not data; prior to 1983, all was Category 1. Cat 2: Certifies UTP for data transmission up to 4 Mbps; 4 twisted pairs Cat 3: Certifies UTP for data transmission up to 10 Mbps; 4 twisted pairs, 3 twists/foot Cat 4: Certifies UTP for data transmission up to 16 Mbps; 4 twisted pairs Cat 5:Certifies UTP for data transmission up to 100 Mbps; 4 twisted pairs
  • Registered Jack-45 , an eight-wire connector used commonly to connect computers onto a local-area networks (LAN) , especially Ethernets . RJ-45 connectors look similar to the ubiquitous RJ-11 connectors used for connecting telephone equipment, but they are somewhat wider. Registered Jack-11 , a four- or six-wire connector used primarily to connect telephone equipment in the United States. RJ-11 connectors are also used to connect some types of local-area networks (LANs) , although RJ-45 connectors are more common.
  • Modulate - To blend data into a carrier signal . At the receiving side, a device demodulates the signals by separating the constant carrier signals from the variable data signals. Fiber-optics use a technology called photonics. Photonics uses the properties of light instead of electricity to transmit data; therefore, it’s completely immune to EMI. Each fiber consists of two pieces of glass: an inner core and an outer core,or cladding. Data travels as impulses of light through the inner core. When the signal tries to escape, the cladding reflects it back. Think of the cladding as a cylindrical mirror surrounding the inner core. Fiber optics is a particularly popular technology for local-area networks . In addition, telephone companies are steadily replacing traditional telephone lines with fiber optic cables. In the future, almost all communications will employ fiber optics.
  • Thin cylinder of glass (core) surrounded by glass cladding; so cable must have two strands in two jackets with kevlar fiber reinforcement. Optical fibers carry signals as pulses of light. Very secure, high speed (100 Mbps=2Gbps), high capacity, can carry pulse for miles.
  • Attentuation is the loss of signal strength over distance. Fiber optics has several advantages over traditional metal communications lines: Fiber optic cables have a much greater bandwidth than metal cables. This means that they can carry more data. Fiber optic cables are less susceptible than metal cables to interference. Fiber optic cables are much thinner and lighter than metal wires. Data can be transmitted digitally (the natural form for computer data) rather than analogically. The main disadvantage of fiber optics is that the cables are expensive to install. In addition, they are more fragile than wire and are difficult to split.
  • Backbone - Another term for bus , the main wire that connects nodes . The term is often used to describe the main network connections composing the Internet . Node - a processing location. A node can be a computer or some other device , such as a printer .
  • Local Area Wireless Network - A type of local-area network that uses high-frequency radio waves rather than wires to communicate between nodes .
  • Access Point: is a transceiver connecting wireless computers to the cabled network; usually wall mounted. Transceiver (transmitter-receiver) - a device that both transmits and receives analog or digital signals. The term is used most frequently to describe the component in local-area networks (LANs) that actually applies signals onto the network wire and detects signals passing through the wire. For many LANs, the transceiver is built into the network interface card (NIC) .
  • Short for t op- l evel d omain, and refers to the suffix attached to Internet domain names . There are a limited number of predefined suffixes, and each one represent a top-level domain.
  • Short for t op- l evel d omain, and refers to the suffix attached to Internet domain names . There are a limited number of predefined suffixes, and each one represent a top-level domain.
  • Most NICs are designed for a particular type of network, protocol , and media. Expansion Board - A printed circuit board that you can insert into a computer to give it added capabilities. For example, all of the following are expansion boards: 1. video adapters 2. graphics accelerators 3. sound cards 4. accelerator boards 5. internal modems Peripheral Component Interconnect - a local bus standard developed by Intel Corporation . Most modern PCs include a PCI bus in addition to a more general ISA expansion bus . PCI is a 64-bit bus, though it is usually implemented as a 32-bit bus. It can run at clock speeds of 33 or 66 MHz . Industrial Standard Architecture - The bus architecture used in the IBM PC/XT and PC/AT . Bus - A collection of wires through which data is transmitted from one part of a computer to another. Plug and Play - Refers to the ability of a computer system to automatically configure expansion boards and other devices . You should be able to plug in a device and play with it, without worrying about setting DIP switches , jumpers , and other configuration elements. Open System Interconnection - an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers. Layer 2 - Data Link Layer - Responsible for physical passing data from one node to another.
  • Registered Jack-45 (RJ-45) - an eight-wire connector used commonly to connect computers onto a local-area networks (LAN) , especially Ethernets . British Naval Connector or Bayonet Nut Connector or Bayonet Neill Concelman - a type of connector used with coaxial cables such as the RG-58 A/U cable used with the 10Base-2 Ethernet system . The basic BNC connector is mounted at each end of a cable. This connector has a center pin connected to the center cable conductor and a metal tube connected to the outer cable shield. A rotating ring outside the tube locks the cable to any receiving type connector. Attachment Unit Interface - the portion of the Ethernet standard that specifies how a cable is to be connected to an Ethernet card. AUI specifies a coaxial cable connected to a transceiver that plugs into a 15-pin socket on the network interface card (NIC) . Transceiver - transmitter-receiver - a device that both transmits and receives analog or digital signals. The term is used most frequently to describe the component in local-area networks (LANs) that actually applies signals onto the network wire and detects signals passing through the wire. For many LANs, the transceiver is built into the network interface card (NIC) . Some types of networks, however, require an external transceiver.
  • The Role of the Network Adapter Card Network adapter cards act as the physical interface or connection between the computer and the network cable. The cards are installed in an expansion slot in each computer and server on the network. After the card has been installed, the network cable is attached to the card's port to make the actual physical connection between the computer and the rest of the network. The role of the network adapter card is to: Prepare data from the computer for the network cable. Send the data to another computer. Control the flow of data between the computer and the cabling system.
  • Always use the latest driver. NT requires special NIC Drivers. Driver - A program that controls a device . Every device, whether it be a printer , disk drive , or keyboard , must have a driver program. Many drivers, such as the keyboard driver, come with the operating system . For other devices, you may need to load a new driver when you connect the device to your computer .
  • Local Area Wireless Network (LAWN) - A type of local-area network that uses high-frequency radio waves rather than wires to communicate between nodes . Nodes - In networks , a processing location. A node can be a computer or some other device , such as a printer .
  • Short for t op- l evel d omain, and refers to the suffix attached to Internet domain names . There are a limited number of predefined suffixes, and each one represent a top-level domain.
  • Short for t op- l evel d omain, and refers to the suffix attached to Internet domain names . There are a limited number of predefined suffixes, and each one represent a top-level domain.
  • Short for t op- l evel d omain, and refers to the suffix attached to Internet domain names . There are a limited number of predefined suffixes, and each one represent a top-level domain.
  • Short for t op- l evel d omain, and refers to the suffix attached to Internet domain names . There are a limited number of predefined suffixes, and each one represent a top-level domain.
  • Before data can be sent over the network, the network adapter card must change it from a form the computer can understand to another form which can travel over a network cable. Data moves through a computer along paths called buses. These are actually several data paths placed side by side. Because several paths are side by side (parallel), data can move along them in groups instead of a single (serial) data stream. Older buses, such as those used in the original IBM personal computer, were known as 8-bit buses because they could move data 8 bits at a time. The IBM PC/AT@ used a 16-bit bus, which means it could move data 16 bits at a time. Many computers use 32-bit buses. When data travels on a computer's bus, it is said to be traveling in parallel because the 16 or 32 bits are moving along side by side. Think of a 16-bit bus as being a 16-lane highway with 16 cars moving side by side (moving in parallel), each carrying one bit of data. On the network cable, data must travel in a single bit stream. When data travels on a network cable it is said to be traveling as a serial transmission because one bit follows another. In other words, the cable is a one-lane highway. The data on these highways always travel in one direction. The computer is either sending or receiving data. The network adapter card takes data traveling in parallel as a group and restructures it so that it will flow through the 1 -bit wide serial path of the network cable. This is accomplished through the translation of the computer's digital signals into electrical and optical signals that can travel on the network's cables. The component responsible for this is the transceiver.
  • When a computer first establishes connectivity on the network it sends out a message to all other computers letting them know it is on the network. Each computer will have a computer name and every other computer will have that name and their associated MAC address stored in memory or CACHE. CACHE - Pronounced cash , a special high-speed storage mechanism. It can be either a reserved section of main memory or an independent high-speed storage device . Media Access Control address , a hardware address that uniquely identifies each node of a network . Network Address Media Access Control (MAC) In addition to transforming data, the network adapter card also has to indicate its location, or address, to the rest of the network to distinguish it from all of the other cards on the network. Network addresses are determined by the IEEE (Institute of Electrical and Electronics Engineers, Inc.) committee. The committee assigns blocks of addresses to each network adapter card manufacturer. The manufacturers hardwire these addresses into chips on the card by a process know as burning the address into the card. With this process each card, and therefore each computer, has a unique address on a network.
  • To begin communicating on a network one computer must put information on the wire which includes the destination computers MAC address. Each computer or host is constantly looking for data which contains its’ MAC. ************************************** Explanation of slide: In this case ABC sends a message with 123s’ MAC address. All the hosts on the network see the message but only the host matching that address will respond. The initial information is to determine a set of parameters in which they can communicate.
  • The receiving host replies: ************************************* Explanation of slide: The sending computer replies with a hand shake setting the guidelines for communications
  • If a newer, faster, more sophisticated card needs to communicate with an older, slower model, both cards need to find a common transmission speed each can accommodate. Some newer network adapter cards incorporate circuitry that allows the card to adjust to the rate of the slower card. Before the sending network adapter card actually sends data over the network, it carries on an electronic dialog, with the receiving card so that both cards agree on the following: Maximum size of the groups of data to be sent. The amount of data to be sent before confirmation. The time intervals between sending data chunks. The amount of time to wait before confirmation is sent. How much data each card can hold before it overflows. The speed of the data transmission.
  • Data tends to exist as rather large files. However, networks cannot operate if computers put large amounts of data on the cable at one time. There are two reasons why putting large chunks of data on the cable at one time slows down the network. First, large amounts of data sent as one large unit ties up the network and makes timely interaction and communications impossible because one computer is flooding the cable with data. The second reason networks reformat large chunks of data into smaller packages is in case there is an error in transmission. Only a small section of data is affected, so only a small amount of data must be resent, making it relatively easy to recover from the error. In order for many users at once to transmit data quickly and easily across the network, the data must be broken into small, manageable chunks. These chunks are called packets, or frames.
  • Packets are the basic units of network communications. With data divided into packets, individual transmissions are speeded up so that every computer on the network will have more opportunities to transmit and receive data. At the target (receiving) computer, the packets are collected and reassembled in the proper order to form the original data.
  • All packets have certain components in common. These include: - A source address identifying the sending computer. - The data that is intended for transmission. - A destination address identifying the recipient. - Instructions that tell network components how to pass the data along. - Information that tells the receiving computer how to connect the packet to other packets in order to reassemble the complete data package. - Error checking information to ensure that the data arrives intact.
  • Highlight the three areas and move to next slide
  • Header The header includes: An alert signal to indicate that the packet is being transmitted. The source address. The destination address. Clock information to synchronize transmission.
  • Trailer The exact content of the trailer varies depending on the communication method, or protocol. However, the trailer usually contains an error checking component called a cyclical redundancy check (CRC). The CRC is a number produced by a mathematical calculation on the packet at its source. When the packet arrives at its destination, the calculation is redone. If the results are the same, it indicates that the data in the packet has remained stable. If the calculation at the destination differs from the calculation at the source, it means the data has changed during the transmission. In that case, the CRC routine signals the source computer to retransmit the data.
  • Data This is the actual data being sent. This part of the packet can be of various sizes, depending on the network. The data section on most networks varies from 512 bytes to 4k. Because most original data strings are much longer than 4k, data must be broken into chunks small enough to be put into packets. It takes many packets to complete the transmission of a large file.
  • C arrier S ense M ultiple A ccess / C ollision D etection, is a set of rules determining how network devices respond when two devices attempt to use a data channel simultaneously (called a collision). Standard Ethernet networks use CSMA/CD. This standard enables devices to detect a collision. After detecting a collision, a device waits a random delay time and then attempts to re-transmit the message. If the device detects a collision again, it waits twice as long to try to re-transmit the message. This is known as exponential back off.
  • Protocol - An agreed-upon format for transmitting data between two devices . The protocol determines the following: the type of error checking to be used data compression method, if any how the sending device will indicate that it has finished sending a message how the receiving device will indicate that it has received a message
  • Open System Interconnection - an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers. OSI Model Layer Name Function 7 Application Layer Program-to-program communication. 6 Presentation Layer Manages data representation conversions. For example, the Presentation Layer would be responsible for converting from EBCDIC to ASCII. 5 Session Layer Responsible for establishing and maintaining communications channels. In practice, this layer is often combined with the Transport Layer. 4 Transport Layer Responsible for end-to-end integrity of data transmission. 3 Network Layer Routes data from one node to another. 2 Data Link Layer Responsible for physical passing data from one node to another. 1 Physical Layer Manages putting data onto the network media and taking the data off.
  • This model is the best known and most widely used guide to describe networking environments. Vendors design network products based on the specifications of the OSI model. It provides a description of how network hardware and software work to-ether in a layered fashion to make communications possible. It also helps with troubleshooting by providing a frame of reference that describes how components are supposed to function. .
  • Protocol Stack - A set of network protocol layers that work together. The OSI Reference Model that defines seven protocol layers is often called a stack, as is the set of TCP/IP protocols that define communication over the internet. The term stack also refers to the actual software that processes the protocols. So, for example, programmers sometimes talk about loading a stack, which means to load the software required to use a specific set of protocols. In Windows , the TCP/IP stack is implemented by the Winsock DLL .
  • The OSI Model and their basic functions
  • Packet - A piece of a message transmitted over a packet-switching network. One of the key features of a packet is that it contains the destination address in addition to the data.
  • Ethernet - A local-area network (LAN) protocol Token Ring - refers to the PC network protocol developed by IBM . The IBM Token-Ring specification has been standardized by the IEEE as the IEEE 802.5 standard .
  • Transmission Control Protocol/Internet Protocol - the suite of communications protocols used to connect hosts on the Internet . TCP-IP will be discussed latter.
  • If TCP/IP is bound first, then TCP/IP will be used to attempt a network connection. If the network connection fails, computer will transparently attempt to connect using the next protocol in the binding order. Binding Process - Another common phrase is binding a stack, which refers to linking a set of network protocols to a network interface card (NIC) . Every NIC must have at least one stack bound to it. Internetwork Packet Exchange ( IPX) - is a datagram protocol used for connectionless communications.
  • IP addressing provided the means for successfully routing packets from one location to another. Point out that MAC addressing is used only on a network segment, when you extend beyond your network another address is required. Short for Media Access Control address , a hardware address that uniquely identifies each node of a network . In IEEE 802 networks, the Data Link Control (DLC) layer of the OSI Reference Model is divided into two sublayers: the Logical Link Control (LLC) layer and the Media Access Control (MAC) layer. The MAC layer interfaces directly with the network media. Consequently, each different type of network media requires a different MAC layer. On networks that do not conform to the IEEE (Institute of Electrical and Electronics Engineers) 802 standards but do conform to the OSI Reference Model, the node address is called the Data Link Control (DLC) address.
  • Abbreviation for Transmission Control Protocol/Internet Protocol , the suite of communications protocols used to connect hosts on the Internet . TCP/IP uses several protocols , the two main ones being TCP and IP . TCP/IP is built into the UNIX operating system and is used by the Internet, making it the de facto standard for transmitting data over networks . Even network operating systems that have their own protocols, such as Netware , also support TCP/IP. UNIX Operating System - Pronounced yoo-niks, a popular multi-user , multitasking operating system developed at Bell Labs in the early 1970s. De facto standard - A format , language , or protocol that has become a standard not because it has been approved by a standards organization but because it is widely used and recognized by the industry as being standard. Netware - A popular local-area network (LAN) operating system developed by Novell Corporation . NetWare is a software product that runs on a variety of different types of LANs, from Ethernets to IBM token-ring networks . It provides users and programmers with a consistent interface that is independent of the actual hardware used to transmit messages.
  • TCP: Manages the assembling of a message or file into smaller packets that are transmitted over the internet and received by a layer that reassembles the packets into the original message. IP: Handles the address to see where to forward the message. During this process some packets are routed differently than others, but are reassembled at their destination.
  • Discuss slide briefly, inform students it will be discussed in much further detail in the following class.
  • The TCP/IP protocol route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address. Within an isolated network, you can assign IP addresses at random as long as each one is unique. However, connecting a private network to the Internet requires using registered IP addresses (called Internet addresses) to avoid duplicates. The four numbers in an IP address are used in different ways to identify a particular network and a host on that network
  • They are issued by Network Administrators. Allows routing devices to efficiently map and connect to hosts or other computer devices.
  • Explain that an IP address is broken into octets or groups ranging from 0-255, and this addressing scheme gives you millions of addresses. Every computer must have an address to communicate in a network. An octet is 8 bits. It is equivalent to a byte, as long as the byte is also 8 bits. Bytes range from 4 - 10 bits, but octets are always 8 bits.
  • The IP Address is just four 8 bit binary numbers. Each number is called an Octet, because it is 8 bits long Two parts of the IP Address, Network and Host
  • The IP Address is just four 8 bit binary numbers. Each number is called an Octet, because it is 8 bits long Two parts of the IP Address, Network and Host
  • On a TCP/IP Network the IP Address is the unique address that will identify networks and hosts. Attached to the data packet It is the 3 rd OSI Layer (network layer)
  • Each network must have a network IP Address and a broadcast IP Address. These do not work for users and are automatically recognized in the router based on the subnet mask. The first IP Address in a network will always be the network address The last IP Address in a network will always be the broadcast address All of the remaining IP Addresses are for users
  • Each network must have a network IP Address and a broadcast IP Address. These do not work for users and are automatically recognized in the router based on the subnet mask. The first IP Address in a network will always be the network address The last IP Address in a network will always be the broadcast address All of the remaining IP Addresses are for users
  • Each network must have a network IP Address and a broadcast IP Address. These do not work for users and are automatically recognized in the router based on the subnet mask. The first IP Address in a network will always be the network address The last IP Address in a network will always be the broadcast address All of the remaining IP Addresses are for users
  • Making smaller networks out of larger networks Use the 172.16.0.0 (class B network) as an example Put yourself in the role as the senior network manager and your students are the subordinate network managers
  • This is an example of a non subnet masked network. All 65,534 users sharing this whole network.
  • Now it is being broken up (subnet masked) into smaller networks. You can now apply the example of you being manager of the class B network 172.16.0.0 and the students being any subnet of that network Subnet – 172.16.1.0 Subnet – 172.16.2.0 And so on
  • Authorization - The process of granting or denying access to a network resource. Most computer security systems are based on a two-step process. The first stage is authentication , which ensures that a user is who he or she claims to be. The second stage is authorization, which allows the user access to various resources based on the user's identity. Driver - A program that controls a device . A driver acts like a translator between the device and programs that use the device. IP Address - An identifier for a computer or device on a TCP/IP network . Networks using the TCP/IP protocol route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. Subnet Mask - A mask used to determine what subnet an IP address belongs to. An IP address has two components, the network address and the host address. Gateway - In networking , a combination of hardware and software that links two different types of networks. Gateways between e-mail systems , for example, allow users on different e-mail systems to exchange messages. WINS - Short for Windows Internet Naming Service, a system that determines the IP address associated with a particular network computer. This is called name resolution. WINS supports network client and server computers running Windows and can provide name resolution for other computers with special arrangements. Domain Name - A name that identifies one or more IP addresses .
  • Device Manager - Device Manager is an OS feature that lets you view and change the properties of all devices attached to your computer . To get to the device manager in Windows , right click on the My computer icon, choose properties, then click on the device manager tab. From there you can select a variety of management options. IRQ - Abbreviation of i nterrupt r e q uest line, and pronounced I-R-Q. IRQs are hardware lines over which devices can send interrupt signals to the microprocessor . When you add a new device to a PC , you sometimes need to set its IRQ number by setting a DIP switch . This specifies which interrupt line the device may use. Input/Output Addresses - Input/output addresses (usually called I/O addresses for short) are resources used by virtually every device in the computer. Conceptually, they are very simple; they represent locations in memory that are designated for use by various devices to exchange information between themselves and the rest of the PC. The diagnostic program for the SMC EtherPower II 10/100 Ethernet Driver is accessed from DOS by typing EZSTART.
  • Packet Internet Groper (PING) - a utility to determine whether a specific IP address is accessible. It works by sending a packet to the specified address and waiting for a reply. Trace Route (Tracert) - A utility that traces a packet from your computer to an Internet host , showing how many hops the packet requires to reach the host and how long each hop takes. If you're visiting a Web site and pages are appearing slowly, you can use traceroute to figure out where the longest delays are occurring. Windows Internet Protocol Configuration (WINIPCFG) - Displays network properties. Network Status (NETSTAT) - Provides network and individual performance status.
  • Packet Internet Groper (PING) - a utility to determine whether a specific IP address is accessible. It works by sending a packet to the specified address and waiting for a reply. Trace Route (Tracert) - A utility that traces a packet from your computer to an Internet host , showing how many hops the packet requires to reach the host and how long each hop takes. If you're visiting a Web site and pages are appearing slowly, you can use traceroute to figure out where the longest delays are occurring. Windows Internet Protocol Configuration (WINIPCFG) - Displays network properties. Network Status (NETSTAT) - Provides network and individual performance status.
  • Here, we pinged computer name of ACD4. We received a reply from the packets sent out, indicating that the connectivity and cables to this point are good.
  • Here, we pinged the ip address of 147.51.17.23. We received a request timed out indicating the packet of data is not making a full connection and something is wrong.
  • Packet Internet Groper (PING) - a utility to determine whether a specific IP address is accessible. It works by sending a packet to the specified address and waiting for a reply. Trace Route (Tracert) - A utility that traces a packet from your computer to an Internet host , showing how many hops the packet requires to reach the host and how long each hop takes. If you're visiting a Web site and pages are appearing slowly, you can use traceroute to figure out where the longest delays are occurring. Windows Internet Protocol Configuration (WINIPCFG) - Displays network properties. Network Status (NETSTAT) - Provides network and individual performance status.
  • 18 CONFIG.SYS - The configuration file for DOS systems . Whenever a DOS computer boots up , it reads the CONFIG.SYS file (if it exists) and executes any commands in it. The most common commands are BUFFERS= and FILES= , which enable you to specify the buffer size and the number of files that can be open simultaneously. Configuration File - A file that contains configuration information for a particular program . When the program is executed , it consults the configuration file to see what parameters are in effect. The configuration file for DOS is called CONFIG.SYS . Older versions of the Windows operating system stores configuration information in files with a. INI extension . The two most important configuration files are WIN.INI and SYS.INI. Starting with Windows 95 , most configuration information is stored in MIF files and in the Registry . Buffer - A temporary storage area, usually in RAM . The purpose of most buffers is to act as a holding area, enabling the CPU to manipulate data before transferring it to a device . AUTOEXEC.BAT - automatically executed batch file, the file that DOS automatically executes when a computer boots up . This is a convenient place to put commands you always want to execute at the beginning of a computing session. For example, you can set system parameters such as the date and time, and install memory-resident programs .

25U11F01.PPT 25U11F01.PPT Presentation Transcript

  • 25U10 F01-LP1 Perform Signal Support Procedures for a Local Area Network
  • LOCAL AREA NETWORKS
    • Identify network types and their common designs.
    • Finally, Achieve a minimum score of 70 percent on a written exam.
    LEARNING OBJECTIVES
    • Identify common network devices and their use.
    • Install and trouble shoot a Local Area Network.
  • LOCAL AREA NETWORKS
    • As a 25U you will be required to:
    • Install A Networks
    • Troubleshoot Networks
  • The term topology, or more specifically network topology, refers to the physical layout of computers, cables, and other components on the network. Network Layout Topology
    • All network designs stem from three basic topologies:
        • Bus : Computers are connected in a row along a single cable segment.
        • Star : Computers are connected to cable segments that branch out from a single point.
        • Ring : Computers are connected to a series of cables that forms a loop.
    Network Layout
  • Network Layout BUS TOPOLOGY
  • STAR TOPOLOGY Network Layout
  • RING TOPOLOGY Network Layout
    • There are four different types
    • of networks
    • Local Area Network (LAN )
    • Metropolitan Area Network (MAN)
    • Wide Area Network (WAN)
    • The Internet
    Types of Networks
  • A network of computers intended to serve an area of only a few square kilometers (or less). Usually a LAN will service an office or building. Local Area Network Types of Networks
  • Metropolitan Area Network (MAN) Although a MAN is based on a LAN standard, it is a network that services a large area like a city, military post, or school campus. Types of Networks
  • Wide Area Network (WAN) A WAN is a network that covers a greater distance. It can be a collection of LAN’s and MAN’s networked over a large area or two computers networked over a large area. Types of Networks
  • The Internet The Internet, sometimes referred as a Global Area Network. To be more specific, The Internet is a network of networks. Types of Networks
    • Although there are four different
    • types of networks based on size, they
    • all stem from two general types of Networks.
    • Local Area Network (LAN)
    • Wide Area Network (WAN)
    Types of Networks
  • A backbone is a media used to connect smaller networks, or nodes, together to create larger networks. BACKBONE
  • 35th 1st COSCOM 82nd Airborne 18th Airborne Corps Ft. Bragg MAN LAN LAN Ft. Drum MAN Ft. Stewart MAN Ft. Campbell MAN LAN WAN LAN LAN LAN LAN LAN LAN LAN LAN Network Design Wide Area Network (WAN)
  • QUESTIONS
  • CHECK FOR LEARNING What is a Topology? Answer: The physical layout of networking components. Name the three basic topologies. Answer: Bus, Star and Ring Which network is intended to serve a few kilometers or less? Answer: Local Area Network (LAN) Which media is used to connect smaller networks together to create larger networks? Answer: Backbone
  • SIGNAL TRANSMISSION
  • Electrical Properties : Rules for how the message travels over transmission media.
    • Attenuation
    • Cross-talk
    • Bandwidth
    Terms To Understand SIGNAL TRANSMISSION
    • Attenuation:
    • The reduction of signal strength.
    • Cross Talk:
    • Induction of an unwanted signal from one circuit into another.
    Simply an advanced form of noise! SIGNAL TRANSMISSION
    • Bandwidth:
    • The capacity of a particular media, the range of frequencies supported in cycles per second.
    • The capacity varies with changes in distance and based on the signaling. Capacity is discussed in bits per second (Bps).
    SIGNAL TRANSMISSION
  • QUESTIONS
  • CHECK FOR LEARNING What is attenuation? Answer: The reduction of signal strength
    • Bound:
    • Consists of a central conductor surrounded by a physical jacket. This offers security, reliability, and speed.
    • Bound Media (Cable):
    • Coaxial
    • Unshielded Twisted Pair - UTP
    • Shielded Twisted Pair - STP
    • Fiber Optics
    CABLE TYPES
  • A. Coaxial B. Twisted Pair: 1. Shielded 2. Unshielded C. Fiber Optic PRIMARY CABLE TYPES
  • Coaxial Cable
  • Baseband RG-58 Broadband COAXIAL CABLE
  • RG-58 COAXIAL CABLE Baseband Broadband A type of digital data transmission in which each medium (wire) carries only one signal, or channel , at a time. A broadband transmission enables a single wire to carry multiple signals simultaneously
  • RG-58 COAXIAL CABLE
      • Most Popular
      • Low Cost
      • 10 MBPS Data Rate
      • Immunity to EMI
      • Easy to Install
      • Thinnet .25 inch
      • Connects Directly to Network Interface Card (NIC)
    RG-58 COAXIAL CABLE
  • Screw-on Crimp-on Compression RG-58 COAXIAL CABLE CONNECTORS
  • Connectors are the weakest link of a network! T-Connector Terminator COAXIAL CONNECTION HARDWARE
  • THINNET THICKNET Coaxial Cable
    • Coaxial Thinnet
      • Can Carry signal up to approximately 185 meters, before attenuation occurs.
      • Family of RG-58/AU (stranded) or /U(solid) cable has 50-ohm impedance
    • Coaxial Thicknet
      • About .5 inch thick; 500 meter segments
      • Often used as a backbone
      • Hard to work with but carries the signal farther
    COAXIAL CABLE
  • Twisted Pair
      • Comprised of pairs of twisted wire.
      • Twisted to cancel electrical noise from adjacent pairs.
      • Easy to Install.
      • If shielded then call shielded twisted pair.
      • Most Widely Used today .
      • Identified for use by categories.
    TWISTED PAIR CABLE
    • Cat 1:
      • Voice Only
    • Cat 2:
      • Data Transmission - 4 MBS
    • Cat 3:
      • Data Transmission - 10 MBS / 3 Twists per foot
    • Cat 4:
      • Data Transmission - 16 MBS
    • Cat 5:
      • Data Transmission - 100 MBS
    UNSHIELDED TWISTED PAIR (UTP) CABLE CATERGORIES
  • This is a wiring diagram that shows how the wires are installed in the RJ-45 connector. RJ45 CONNECTOR - (UTP)
    • To reduce sensitivity to electrical noise, STP has shielding.
    • Prevents cross talk with foil wrap between and around pairs and internal twisting of the pairs.
    • Uses RJ-45 connectors (8 wire)
    SHIELDED TWISTED PAIR (STP)
  • FIBER OPTICS
    • A technology that uses glass (or plastic) threads
    • (fibers) to transmit data.
    • A fiber optic cable consists of a bundle of
    • glass threads, each of which is capable of
    • transmitting messages modulated onto
    • light waves.
    FIBER OPTICS
  • FIBER OPTIC CABLES BREAKDOWN
  • Advantages
    • Has data rates from 100 MBS to over 2 GBS
    • No attenuation and is immune to EMI
    • Disadvantages
    • Very Expensive
    • Not easy to install
    FIBER OPTICS
    • Use when data must be transmitted at very high speeds over long distances in a very secure media.
    • Expensive.
    • Difficult to install.
    FIBER OPTICS CONSIDERATIONS
  • A backbone is a media used to connect smaller networks, or nodes, together to create larger networks. BACKBONE
  • WIRELESS NETWORKS
    • The Wireless Environment: Emerging Technology
    • Wireless Capabilities:
        • Temporary connections to an existing, cabled network.
        • Backup to existing network.
        • Portable.
        • Extends networks beyond limits of cables.
    • Local area networks: use transmitters and receivers.
    • Extended local area networks.
    • Mobile computing: uses public carriers.
    TYPES OF WIRELESS NETWORK
  • 1) Busy areas. (lobbies, reception area) 2) People who must travel while working. 3) Isolated areas and buildings. 4) Departments that move frequently. 5) Structures that are difficult to cable. USES FOR A WIRELESS NETWORK
  • QUESTIONS
  • CHECK FOR LEARNING What are the three primary types of cables? Answer: Coaxial, Twisted Pair and Fiber Optics Name the RG-58 coaxial connectors? Answer: Screw On, Compression and Crimp On True or False A Thicknet coaxial cable can carry a signal 650 meters before attenuation occurs. Answer: False
  • PRACTICAL EXERCISE # 1 CABLE CREATION
  • INTRODUCTION TO NETWORKING DEVICES Network Devices Network devices are equipment that is used to connect networks together and/or enhance network performance.
  • INTRODUCTION TO NETWORKING DEVICES Network Interface Card An expansion card installed in your computer that puts the data on the network media.
  • An expansion board you insert into a computer so the computer can be connected to a network. Can be either PCI or ISA and optional Plug and Play NETWORK INTERFACE CARDS (NIC)
  • Comes in 3 basic Connector types: RJ-45 – Twisted Pair – Star Topology RJ is abbreviated for Registered Jack BNC – Coaxial Cable – BUS Topology The acronym BNC is British Naval Connector. NETWORK INTERFACE CARDS (NIC)
  • ROLE OF THE NETWORK ADAPTER CARD
    • Prepares data from the computer for the network cable.
    • Sends the data to another computer.
    • Controls the flow of data between the computer and the cabling system.
  • NIC DRIVERS
    • Each Network Card has it’s own drivers.
    • Operating systems such as Windows often have generic drivers.
    • Has a connector for fiber optic connections.
    • Can be either PCI or ISA.
    FIBER OPTICS NETWORK CARD                                               
  • WIRELESS LAN ADAPTERS Wireless LAN adapters allow you to network computers without a direct connection or they can be directly connected.
  • Networking Devices HUB A device used in a star topology as the central point to connect all the computers together.
  • STACKING HUBS If you may need to add more Users to your network and do not have enough ports on your hub to support this, you may stack hubs to add more ports to your network. This is done by using a Crossover cable.
  • Repeater A device in a bus topology used to strengthen a signal and extend the network. Networking Devices
  • Router A network device, commonly referred as a smart link, used to connect networks together. A router will route data through networks to reach it’s destination. A Router uses a Rollover cable to connect from the Router to the computer or hub. Networking Devices
  • Network Switch A device, similar to a hub, used on a star topology to send a signal through to it’s destination. Networking Devices
  • QUESTIONS
  • CHECK FOR LEARNING Name the central point of a Star topology. Answer: Hub What device is used to strengthen the signal of the network? Answer: Repeater What does BNC stand for? Answer: British Navel Connector
  • Practical Exercise # 2 Design a Network
  • Before data can be sent over the network, the network adapter card must change it from a form the computer can understand to another form which can travel over a network cable. PREPARING THE DATA
  • NETWORK ADDRESSES
    • The network adapter card also has to indicate its location, or address, to the rest of the network distinguishing it from all other cards on the network.
    • That address is referred to as the Media Access
    • Control (MAC) or MAC address.
    1234567 ABCDEFG
  • 1234567 ABCDEFG MAC ADDRESS LOOKING FOR
  • 1234567 ABCDEFG MAC ADDRESS SEND REPLY
  • SENDING AND CONTROLLING DATA Each card signals to the other indicating its parameters and accepts or adjusts to the other card's parameters. When all of the communication details have been determined, the two cards begin sending and receiving data.
  • PACKET CONSTRUCTION
  • Data tends to exist as rather large files. However, networks cannot operate if computers put large amounts of data on the cable at one time. THE FUNCTIONS OF PACKETS IN NETWORK COMMUNICATIONS
  • PACKET STRUCTURE
    • Packets may contain several types of data including:
    • Information, such as messages or files.
    • Certain types of computer control data and commands.
    • Session control codes, such as error correction, that indicate the need for a retransmission.
  • PACKET COMPONENTS
    • All packets have certain components in common.
    • These include:
    • A source address (Sender)
    • Data that is intended for transmission.
    • A destination address (Recipient)
    • Instructions (How to pass data)
    • Information(Connect/Reassemble packets)
    • Error checking information
  • Packet Construction HEADER DATA TRAILER
  • HEADER The HEADER includes: - An alert signal to indicate that the packet is being transmitted. - The source address. - The destination address. -Clock information to synchronize transmission .
  • TRAILER The exact content of the TRAILER varies depending on the communication method, or protocol. However, the trailer usually contains an error checking component called a cyclical redundancy check (CRC). The CRC is a number produced by a mathematical calculation on the packet at its source. When the packet arrives at its destination, the calculation is redone.
  • DATA This is the actual data being sent. This part of the packet can be of various sizes depending on the network. The data section on most networks varies from 512 bytes to 4k.
    • C arrier S ense M ultiple A ccess / C ollision D etection
    • Protocol for how Network devices respond when two devices attempt to use a data channel at the same time.
    • After detecting a collision, a device waits a random delay time and then attempts to re-transmit the message .
    CSMA / CD
  • QUESTIONS
  • CHECK FOR LEARNING What are the three parts of Packet Construction? Answer: Header, Data and Trailer Where does the MAC address come from? Answer: It is factory written on the network interface card What is the purpose of CSMA / CD? Answer: To detect and prevent collisions of data packets on the network.
  • PROTOCOLS
    • Protocols are rules and procedures for communicating across a network.
  • PROTOCOLS
    • How protocols work:
    • (1) Data transmission is a step-by-step process.
    • (2) Each step has its own protocol, or rules.
  • THE OSI MODEL In 1978, the International Standards Organization (ISO) released a set of specifications that described a network architecture for connecting dissimilar devices. In 1984, the ISO released a revision of this model and called it the Open Systems Interconnection (OSI) reference model.
  • THE OSI MODEL
    • Protocols in a Layered Architecture
    • Protocols have to work together to ensure data is prepared, transferred, received, and acted upon.
    • Protocol stacks:
    • (a) Each OSI layer has its own protocol (rules).
    • (b) Combination is called a protocol stack.
    • (c ) Lower layers determine how vendors design hardware.
    • (d) Upper layers define rules for communication.
    • (e) The higher the layer is in the stack, the more complex its tasks and their associated protocols.
  • PACKET APPLICATION (OSI MODEL) 1 PHYSICAL LAYER 2 DATA LINK LAYER 3 NETWORK LAYER 4 TRANSPORT LAYER 5 SESSION LAYER 6 PRESENTATION LAYER 7 APPLICATION LAYER C Converts data to a program format Completion of packet transmission Performs error checking of data(protocols) Contains destination IP address Contains destination MAC address Receives raw data from the wire Places packets into a file format
  • PROTOCOLS
    • Sending computer:
    • Its protocol breaks data into packets that the protocol can handle.
    • Adds addressing information.
    • Prepares and sends data out onto the network cable.
    • Receiving computer:
    • Must use same protocol to take packet off the cable.
  • PROTOCOLS
    • Both computers must process packets following exactly the same procedures.
    • Rules for communicating in a particular LAN environment, such as, Ethernet are known as Network Protocols .
  • PROTOCOLS
    • ROUTABLE vs. NONROUTABLE Protocols:
    • Data sent from one LAN to another is routed.
    • Routable protocols can navigate to a specific address, i.e. TCP/IP.
    • Non-routable protocols broadcast to everyone.
  • PROTOCOLS
    • Allows network protocols and card to be mixed.
    • Two or more protocols can be bound to one card.
    • Operating System (OS) will attempt to use the protocols in the order they are bound.
    The Binding Process
  • PROTOCOLS
    • IP (Internet Protocol): TCP/IP protocol for packet forwarding and routing.
    • Protocols are implemented and removed in much the same way that drivers are added and removed.
  • QUESTIONS
  • CHECK ON LEARNING What are protocols? Answer: They are rules or standards that allow computers to communicate with each other. Which OSI layer performs error checking of data? Answer: Layer 4 (The Transport Layer). How many layers does the OSI model consist of? Answer: 7
  • TRANSMISSION CONTROL PROTOCOL / INTERNET PROTOCOL TCP/IP
  • TCP/IP
    • Basic communication language or protocol for the internet.
    • Two layered program:
    • 1)Transmission Control Protocol
    • 2) Internet Protocol
  • TCP/IP
    • Two Layers
    • T ransmission C ontrol P rotocol/ I nternet P rotocol:
    • TCP: Manages the assembling of a message or file.
    • IP: Handles the address to see where to forward the message.
  • IP ADDRESSES 148.43.200.16 LET’S TALK IP ADDRESSES
  • IP ADDRESSES Think of an IP address like you would your mailbox address. It represents your computer across a network like your house address represents you across the country. 148.43.200.16
  • IP ADDRESSES
    • IP address: An address used to determine a location of a host or other computer device.
    148.43.200.16
  • IP ADDRESS BREAKDOWN This address is broken down into what we call octets. Each octet has a possible 256 numbers ranging from 0-255. 148.43.200.16 0-255 0-255 0-255 0-255 148 43 200 16
  • IP Addressing In a TCP/IP network there are 5 classes of IP address. Each is identified by the number in the first octet. Class A: 1-126 Class B: 128-191 (The military uses class B) Class C: 192-223 Class D: 224-239 (Experimental purposes) Class E: 240-255 (Experimental purposes) NOTE: 127 IS RESERVED AS A LOOPBACK ADDRESS FOR TESTING PURPOSES
  • IP Addressing 148.17.56.16 10010100.00010001.00111000.00010000 NETWORK HOSTS IP addresses are broken down into 2 parts; the Network portion and the Host/User. The computer reads these IP addresses as a series of 1’s and 0’s.
  • IP Addressing
    • 64 32 16 8 4 2 1
    • 1 0 0 1 0 1 0 0
    1’s are considered ON and 0’s are OFF ADD the numbers turned on to get the number for that octet. 128 + 16 + 4 = 148
  • IP Addressing 148.43.202.3 148.43.202.2 148.43.202.1 148.43.202.4 148.43.201.2 148.43.201.1 148.43.200.4 148.43.200.3 148.43.200.2 148.43.200.1 Each Device must have a unique number to identity itself
  • 147.51.175.0 Network Address 147.51.175.1 Hosts/Users 147.51.175.254 147.51.175.255 Broadcast 255.255.255.0 Sub mask Every network must have a network IP Address and a broadcast IP Address. The Network and Broadcast IP addresses are not issued to the Users, but must encapsulate all User IP addresses. IP Addressing
  • IP Addressing exercise Network Network IP Broadcast IP 197.10.100.0 thru ? ? 197.10.100.255 147.55.126.16 thru ? ? 147.55.126.31 192.18.0.0 thru ? ? 192.18.255.255
  • IP Addressing answers Network Network IP Broadcast IP 197.10.100.0 thru 197.10.100.0 197.10.100.255 197.10.100.255 147.55.126.16 thru 147.55.126.16 147.55.126.31 147.55.126.31 192.18.0.0 thru 192.18.0.0 192.18.255.255 192.18.255.255
  • Subnet Masking A subnet further breaks down the block of IP’s that you have been given from the ISP. Example: If a company is given 172.16.0.0 as their block of IP addresses, they may elect to connect all their computers to the single network, which can result in poor network performance. What is subnet masking?
  • One option of networking is to connect all workstations to one network. Subnet Masking Network 172.16.0.0 172.16.0.0
  • If you break down the network, you could limit the traffic on the other networks. Subnet Masking Network 172.16.0.0 172.16.1.0 172.16.2.0 172.16.3.0 172.16.4.0
  • Subnet Masking: RULES 1. Bits=Number of bits turned on in the Host/User octet 2. Subnet=Sum of mask bits turned on in each octet 3. Mask Bits=Number of bits turned on in all Octets 4. # of Subnets=2 to the power of the number of bits turned on, minus 2(network & broadcast) 5. Host/User=Number of users minus 2 (network & broadcast)
  • Subnet Masking
    • 64 32 16 8 4 2 1
    • 64 32 16 8 4 2 1
    • 64 32 16 8 4 2 1
    • 64 32 16 8 4 2 1
    When starting to Subnet, to make things easier, draw this chart out first. This chart represents each octet of your IP address.
  • Subnet Masking Bits Subnet Mask Mask Bits # of Subnets # of Host/User # of Bits turned on in the Host/User octet of the IP address Sum all Bits turned on in each octet # of Bits turned on in all 4 octets Formula: 2 to the power Bits turned on in the Host/User octet Minus 2 The first Bit turned on in the Host/User octet minus 2 (Network and Broadcast) NOTE: After drawing the previous chart, draw this chart.
  • 192.50.100.0 255.255.255.0 25 Users Using your 2 charts drawn from the previous slides, we will subnet this one IP Address and get the required amount of Host/User IP addresses and Subnet Mask. Subnet Masking
  • Bits Subnet Mask Mask Bits # of Subnets # of Host/User 3 255.255.255.224 /27 6 30 NETWORK 192.50.100.32 USERS 192.50.100.33 192.50.100.62 BROADCAST 192.50.100.63 Subnet Masking answers
  • QUESTIONS
  • CHECK FOR LEARNING What is an IP address? Answer: An address used to determine a location of a host or other computer device. What is the range of each octet in an IP address? Answer: Each octet of an IP address has a range of 0-255. What are the 2 parts of an IP address? Answer: Network and Hosts.
  • CHECK FOR LEARNING What does the acronym TCP/IP stand for? Answer: Transmission Control Protocol / Internet Protocol TCP/IP is made up of how many layers? Answer: 2 The number 192 in the first octet of an IP address signifies what class of IP address? Answer: Class C
  • Practical exercise # 3 192.100.50.0 255.255.255.0 50 Users
  • INSTALLING A NETWORK INTERFACE CARD (NIC) DRIVER
  • PREPARATION
    • Authorization - User Name and Password
    • Network Card Drivers - Floppy Disk or CD-ROM
    • IP Addresses - Computer, Subnet Mask, Gateway, DNS Service Search Order, and WINS Server
    • Computer Name - Name that computer will be known as across network
    • Workgroup Name or Domain Name
    Items to have ready prior to installation:
  • NETWORK CARD IRQ AND I/O
    • Windows NT does not have a Device Manager to resolve hardware conflicts or to make changes to the IRQ or I/O range.
    • To change the IRQ and/or the I/O range of a device, you must run the diagnostic program for the device.
  • METHOD OF INSTALLING EXPANSION BOARD DRIVERS
    • Almost all expansion board drivers can be installed on Windows NT operating system by:
    • Floppy Disk CD-ROM Network Manufacturer Website
    • For example, you can not install a NIC driver from the network because you are not connected to the network.
  • INSTALLING NETWORK SETTINGS To begin installing your network settings, Right click on the Network Neighborhood Icon and Select Properties.
  • INSTALLING NETWORK SETTINGS At the Network Neighborhood Properties window select the Adapters Tab.
  • INSTALLING NETWORK SETTINGS If there are any Network adapters, highlight them and click Remove. Then Reboot your Computer. Once Reboot is complete return to the Adapters Tab. If no Adapters are present, Click the ADD button.
  • INSTALLING NETWORK SETTINGS The Select Network Adapter window appears, Click: Have Disk
  • INSTALLING NETWORK SETTINGS Insert your Drivers disk into your Floppy Drive and Ensure that there is an A: in the location box. Click OK
  • INSTALLING NETWORK SETTINGS The Select OEM Option window appears with the Network Card type in the window. Click OK.
  • INSTALLING NETWORK SETTINGS At the Input Ethernet ID window click on SKIP. This option is only used if more than one Network Adapter is installed.
  • INSTALLING NETWORK SETTINGS The adapter type window appears, for Realtek RTL 8019 select ISA, for Realtek RTL 8029 select PCI. Click OK
  • INSTALLING NETWORK SETTINGS Windows NT will begin copying files necessary for the installation of the Network Adapter.
  • INSTALLING NETWORK SETTINGS The Adapter window now appears with the appropriate Adapter installed. Click the Bindings Tab.
  • INSTALLING NETWORK SETTINGS Windows NT will now Bind your Network Adapter to the Protocols installed.
  • INSTALLING NETWORK SETTINGS At the Binding Tab click the Close button.
  • INSTALLING NETWORK SETTINGS You are now taken to the Microsoft TCP/IP Properties window. Input your IP Address, Subnet Mask, and Default Gateway. This information is located in your Student Position Binder.
  • INSTALLING NETWORK SETTINGS In the DNS Tab enter your DNS addresses by clicking the ADD button. Ensure that your Domain Address is Gordon.army.mil.
  • INSTALLING NETWORK SETTINGS Click the WINS Address Tab. Enter your WINS Address. Click the Apply button then Click OK.
  • INSTALLING NETWORK SETTINGS You are now prompted to Restart, click YES to restart. Once you have Restarted, Log on as Administrator and go to your Desktop.
  • INSTALLING NETWORK SETTINGS At the Windows NT Desktop, Right Click on Network Neighborhood and Select Properties.
  • INSTALLING NETWORK SETTINGS At the Network Properties Window, Click on the Change button.
  • INSTALLING NETWORK SETTINGS At the Identification changes window, change your computer name to your Host Name, I.E. wsf175___. This will be the computer name seen across the Network. Click OK.
  • INSTALLING NETWORK SETTINGS You are now informed that the computer name has been successfully changed but a Restart is necessary. Click OK.
  • INSTALLING NETWORK SETTINGS Close out the Network Properties window by clicking on the Close button.
  • INSTALLING NETWORK SETTINGS Click Yes to Restart your computer now. Once Restart is complete Log on as Administrator.
  • INSTALLING NETWORK SETTINGS At the Windows NT Desktop Right Click the Network Neighborhood Icon and select Properties.
  • INSTALLING NETWORK SETTINGS At the Identification Tab click on the Change Button.
  • INSTALLING NETWORK SETTINGS Click the Radio button next to Domain and enter 52div Check mark the box for Create a Computer account in the Domain and enter your User name and Password. Click OK.
  • INSTALLING NETWORK SETTINGS At the Welcome to the 52DIV window click OK. Click OK at the Identification Changes window if necessary.
  • INSTALLING NETWORK SETTINGS At the Network Identification window click the Close button.
  • INSTALLING NETWORK SETTINGS You are prompted to Restart, Click the YES button. After restart is complete log on as Administrator and go to the Windows NT Desktop.
  • INSTALLING NETWORK SETTINGS Double Click the Network Neighborhood Icon and you are now able to see all computers within your Domain.
  • QUESTIONS ?
  • Practical Exercise # 4 Install Network Settings and Join the Domain
  • Troubleshooting the Network Introduction Applying a logical process is the key to any kind of troubleshooting. There are multiple ways to fix any problem. The better you understand a problem solving process, the easier it is to fix the problem.
  • Fixing any problem can be simple. You are given a big problem. Break the big problem down into several little problems. Utilize a network diagram to give yourself an overlooking view of the network. Use a logical process to identify smaller portions of the network to fix first. Troubleshooting the Network
  • HUB HUB A large network that has a problem Troubleshooting the Network
  • HUB HUB Divide it into two smaller networks Fix the two smaller networks individually Troubleshooting the Network
    • We use troubleshooting tools to assist
    • in isolating network faults. The two
    • tools most valuable are:
      • PING (TCP/IP DOS Command)
      • Testing Equipment
    Troubleshooting the Network
  • PING : Tests connectivity from the computer to the distant end.
    • SYNTAX
      • PING IP Address
    • EXAMPLE
      • PING 147.51.169.7
    Troubleshooting the Network
  • To use the Ping Command, open the Ms-dos command Prompt by choosing Start, Programs and Ms Dos Command Prompt Troubleshooting the Network
  • This ping demonstrates good connectivity to the computer acd4 Troubleshooting the Network
  • This ping demonstrates loss of connectivity to the computer Troubleshooting the Network
  • Test Equipment : Specialized devices to test cables and equipment for serviceability and correct installation. LAN Cable Tester : Specialized devices to test LAN cables for correct construction and serviceability. Some can test LAN data flow. Troubleshooting the Network
    • Detailed records are a tremendous aid in troubleshooting. Records you should keep include:
      • Description of all hardware, to include installation dates and configuration details.
      • A network diagram.
      • Service agreements and warranty information, to include telephone numbers of vendors.
      • A history of past problems.
    Troubleshooting the Network
  • QUESTIONS
  • CHECK ON LEARNING What is the PING command used for? Answer : To check connectivity from the computer to the distant end. What kind of command is PING? Answer : PING is a TCP/IP DOS Command.
  • Practical Exercise # 5 Perform Troubleshooting Techniques