NETWORKING PRELIM.pdf

GROUP 1 MEDIA ACCESS CONTROL PHYSICAL POINT-TO-POINT TOPOLOGY PHYSICAL TOPOLOPGY LOGICAL POINT-POINT TOPOLOGY STAR LOGICAL TOPOLOGY EXTENDED STAR...

GROUP 1 MEDIA ACCESS CONTROL PHYSICAL POINT-TO-POINT TOPOLOGY PHYSICAL TOPOLOPGY LOGICAL POINT-POINT TOPOLOGY STAR LOGICAL TOPOLOGY EXTENDED STAR BUS POINT-TO-POINT RING HUB AND SPOKE MESH HALF-DUPLEX COMMUNICATION FULL-DUPLEX COMMUNICATION  GROUP 1 MEDIA ACCESS CONTROL METHODS CSMA/CD THE FRAME CSMA/CA FRAME START AND STOP INDICATOR FLAGS ADDRESSING LAN AND WAN FRAMES TYPE CONTROL DATA  GROUP 2 Data Link Sublayers DATALINK LAYER Data link layer is divided into two sublayers: Logical Link Control (LLC) Communicates with the network layer. Identifies which network layer protocol is being used for the frame. Allows multiple Layer 3 protocols, such as IPv4 and IPv6, to utilize the same network interface and media. Media Access Control (MAC) Defines the media access processes performed by the hardware. Provides data link layer addressing and access to various network technologies. Communicates with Ethernet to send and receive frames over copper or fiber-optic cable. Communicates with wireless technologies such as Wi-Fi and Bluetooth. Media Access Control Data Link Layer Standards As packets travel from the source host Engineering organizations that define open to the destination host, they travel standards and protocols that apply to the over different physical networks. network access layer include: Physical networks can consist of Institute of Electrical and Electronics different types of physical media such Engineers (IEEE) as copper wires, optical fibers, and International Telecommunication Union wireless consisting of electromagnetic (ITU) signals, radio and microwave International Organization for frequencies, and satellite links. Standardization (ISO) American National Standards Institute (ANSI)  GROUP 3 Characteristics of Copper Media Copper Media There are three main types of copper media used in  Transmitted on copper cables as networking. electrical pulses. Attenuation - the longer the signal travels, the more it deteriorates.  All copper media must follow strict distance limitations.  Electromagnetic interference (EMI) or radio frequency interference (RFI) - distorts and corrupts the data signals being carried by copper media. Crosstalk - disturbance caused by the electric or magnetic fields of a signal on one wire to the signal in an 1. UNSHIELDED TWISTED-PAIR (UTP) CABEL adjacent wire. 2. SHIELDED TWISTED-PAIR (STP) CABLE  To cancel crosstalk opposing 3. COXIAL CABLE circuit wire pairs twisted together. Shielded Twisted-Pair (STP) Cable Unshielded Twisted-Pair Cable  STP provides better noise protection than UTP. UTP cabling is the most common networking media.  STP cable is significantly more Terminated with RJ-45 connectors. expensive and difficult to install. Used for interconnecting network hosts with networking devices such as switches.  Uses an RJ-45 connector. Consists of four pairs of color-coded wires that have been twisted together to help  Combines the techniques of protect against signal shielding to counter EMI and RFI, and interference from other wires. wire twisting to counter crosstalk. Color codes aid in cable termination. Coaxial Cable  A copper conductor used to transmit the electronic signals.  A layer of flexible plastic insulation surrounding a copper conductor.  GROUP 3 UTP Cabling Standards UTP Connectors UTP cable terminated with an RJ-45 UTP cabling conforms to the connector. standards established by TIA/EIA.  TIA/EIA-568 standard describes the wire TIA/EIA-568 stipulates the cabling standards color codes to pin assignments (pinouts) for LAN installations for Ethernet cables. Cat 3 Cable  RJ-45 connector is the male component, Used for voice communication crimped at the end of the cable. Most often used for phone lines  Socket is the female component of a Cat 5 and 5e Cable network device, wall, cubicle partition Used for data transmission outlet, or patch panel. Cat5 supports 100 Mb/s and can support 1000Mb/s, but it is not recommended Cat5e supports 1000 Mb/s Cat 6 Cable Used for data transmission An added separator is between each pair of wires allowing it to function at higher speeds Testing UTP Cables Fiber Media Cable Design UTP Testing Parameters:  Wire map  Cable length  Signal loss due to attenuation  Crosstalk  GROUP 3 Properties of Wireless Media- Types of Wireless Media -Wireless media carry electromagnetic signals that represent Wi-Fi: Standard IEEE 802.11 the binary digits of data communications Uses Carrier/Sense Multiple using radio or microwave frequencies. Access/Collision Avoidance (CSMA/CA). Wireless NIC must wait till channel is Coverage area: Construction materials clear. used in buildings and structures, and the local terrain, will limit the coverage. Bluetooth: Standard IEEE 802.15 Wireless Personal Area Network Interference: Disrupted by such (WPAN) common devices as fluorescent lights, Uses a device pairing process for microwave ovens, and other wireless distances 1 to 100 meters communications. WiMAX: Standard IEEE 802.16 Security: Devices and users, not Worldwide Interoperability for authorized for access to the network, Microwave Access can gain access to the transmission. Wireless broadband access. Shared medium: Only one device can send or receive at a time and the wireless medium is shared amongst all wireless users. Wireless LAN Wireless Access Point (AP): Concentrates the wireless signals from users and connects to the existing copper-based network infrastructure, such as Ethernet. Wireless NIC adapters: Provide wireless communication capability to each network host.  GROUP 4 The Physical Layer Network Interface Cards Provides the means to transport  Network Interface Cards (NICs) the bits that make up a data link connect a device to a network. layer frame across the network media.  Used for a wired connection. Accepts a complete frame from  Wireless Local Area Network the data link layer and encodes it (WLAN) NICs are used for wireless as a series of signals that are connections transmitted onto the local media. Encoded bits that comprise a frame are received by either an end device or an intermediate device Physical Layer Standards  International Organization for Standardization (ISO) - they make rules for lots of industries. Telecommunications Industry  Association/Electronic Industries Association (TIA/EIA) - they focus on how we send information, like over the internet.  International Telecommunication Union (ITU) - a UN agency that helps countries communicate with each other. American National Standards Institute (ANSI) - they make rules for American industries.  Institute of Electrical and Electronics Engineers (IEEE) - they’re big on electronics and communication technology.  GROUP 4 Bandwidth Functions Capacity of a medium To carry data. Digital bandwidth measures the amount of data that can flow from one place EncodIng to another in a given amount of time. Method of converting a stream of data bits into a Bandwidth is sometimes thought of as the speed that bits predefined "code”. travel, however this is not accurate. In both 10Mb/s and 100Mb/s Ethernet, the bits are sent at Signaling Method the speed of electricity. The difference is Method of representing the the number of bits that are transmitted per second. bits. Physical layer standards must define what type of THROUGHPUT signal represents a "1" and what type of signal  Measure of the transfer of bits represents a "0”. across the media over a given period Long pulse might represent of time. a 1 whereas a short pulse  Usually does not match the specified represents a 0. bandwidth in physical layer implementations due to many factors. Types of Physical Media Amount of traffic The figure shows different types of interfaces and Type of traffic ports available on a 1941 router. Latency created by network devices encountered between source and destination Goodput is throughput minus traffic overhead for establishing sessions, acknowledgments, and encapsulation.  GROUP 5 Message Segmentation Protocol Data Units  Large streams of data are divided  As application data is passed down the protocol into smaller, more manageable stack, information is added at each level. This is pieces to send over the network. known as the encapsulation process.  The form that the data takes at each layer is  By sending smaller pieces, many known as a Protocol Data Unit (PDU). different conversations can be interleaved on the network, called Data - application layer PDU multiplexing. Segment – Transport layer PDU Packet – Network layer PDU Frame – Data Link Layer PDU Encapsulation Example Bits – Physical Layer PDU The encapsulation process works from top to bottom: De-encapsulation Data is divided into segments.  The de-encapsulation process The TCP segment is encapsulated works from bottom to top. in the IP Packet.  De-encapsulation is the process The IP packet is encapsulated in the used by a receiving device to Ethernet Frame. remove one or more of the protocol headers. Data Link Addresses Network Addresses The purpose of the data link Network layer source and destination address is to deliver the data link addresses – Responsible for delivering the IP frame from one network interface packet from the original source to the final to another network interface on destination. the same network. Source IP address - The IP address of the sending device, the original source of the packet. Destination IP address - The IP address of the receiving device, the final destination of the packet. Devices on the Same Network The network layer addresses, or IP addresses, indicate the original source and final destination. Network portion – The left-most part of the address indicates which network the IP address is a member of. Host portion – The remaining part of the address identifies a specific device on the network. The data link frame which uses MAC addressing, is sent directly to the receiving device. Source MAC address - address of sending device. Destination MAC address – address of receiving device.  GROUP 5 Devices on a Remote Network  Sending to a remote network – the source and destination IP addresses represent hosts on different networks.  The data link frame cannot be sent directly to the remote destination host. Therefore the frame is sent to the default gateway (nearest router interface). GROUP 6 Rules that Govern Communications Network Protocols Protocol suites are implemented by hosts Networking protocols define a common format and networking devices in software, and set of rules for exchanging messages hardware or both. between devices. Protocol Interaction Some common networking protocols are Hypertext Transfer Protocol (HTTP),  Communication between a web server and Transmission Control Protocol (TCP), and web client is an example of an interaction Internet Protocol (IP). between several protocols: HTTP - an application protocol that governs the Development of TCP/IP way a web server and a web client interact. Advanced Research Projects TCP - transport protocol that manages the Agency individual conversations. Network (ARPANET) was the IP – encapsulates the TCP segments into predecessor to today’s Internet. packets, assigns addresses, and delivers to the destination host. ARPANET was funded by the U.S. Ethernet - allows communication over a data Department of Defense for use by link and the physical transmission of data on the universities and research network media. laboratories. Internet Standards Internet Society (ISOC) –promotes open development and evolution of Internet use globally. Internet Architecture Board (IAB) - management and development of Internet standards. Internet Engineering Task Force (IETF) -develops, updates, and maintains Internet and TCP/IP technologies. Internet Research Task Force (IRTF) -focused on long-term research related to Internet and TCP/IP protocols.  GROUP 6 Internet Corporation for Assigned Names and Numbers (ICANN) - coordinates IP address allocation and management of domain names. Internet Assigned Numbers Authority (IANA) - manages IP address allocation, domain name management, and protocol identifiers for ICANN. Electronics and Communications Standard Organizations Institute of Electrical and Electronics Engineers (IEEE) - dedicated to advancing technological innovation and creating standards in a wide area of industries including networking. Electronic Industries Alliance (EIA) - standards related to electrical wiring, connectors, and network racks. Telecommunications Industry Association (TIA) standards for radio equipment, cellular towers, Voice over IP (VoIP) devices, and satellite communications. International Telecommunications UnionTelecommunication Standardization Sector (ITU-T) standards for video compression, Internet Protocol Television (IPTV), and broadband communications. The OSI Reference Model Application - contains protocols used for process- to-process communications. Presentation - provides for common representation of the data. Session - provides services to the presentation layer to organize its dialogue and to manage data exchange. Transport - defines services to segment, transfer, and reassemble the data. Network - provides services to exchange the individual pieces of data over the network between identified end devices. Data Link - provides methods for exchanging data frames between devices over a common media. Physical - describes the mechanical, electrical, functional, and procedural means to transmit bits across physical connections.  GROUP 6 The TCP/IP Protocol Model OSI Model and TCP/IP Model Comparison The TCP/IP Protocol Model In the OSI model, the network access layer and the Created in the early 1970s for application layer of the TCP/IP model are further internetwork communications. divided to describe discrete functions that must occur at these layers. Open Standard. Also called The TCP/IP Model or the Internet Model. GROUP 7 RULE ESTABLISHMENTS Communication Fundamentals Protocols are necessary for effective All communication methods have three elements in communication and include: common: An identified sender and receiver Source or sender Common language and grammar Destination or receiver Speed and timing of delivery Channel or media Confirmation or acknowledgment Rules or protocols govern all methods of communication. requirements Protocols used in network communications MESSAGE ENCODING also define: Message encoding Encoding between hosts must be in Message delivery options appropriate format for the medium. Message Formatting and Encapsulation Messages are first converted into bits by the Message Timing sending host. Message Size Each bit is encoded into a pattern of sounds, Message Formatting and Encapsulation light waves, or electrical impulses depending on the network media A frame acts like an envelope providing destination address and source address. Message Size Humans break long messages into smaller parts or sentences. Long messages must also be broken into smaller pieces to travel across a  Message Timing Access Method Hosts on a network need to know when to begin sending messages and how to respond when collisions occur. Flow Control Source and destination hosts use flow control to negotiate correct timing to avoid overwhelming the destination and ensure information is received. Response Timeout Hosts on the network have rules that specify how long to wait for responses and what action to take if a response timeout occurs. Message DELIVERY OPTIONS