Networking Fundamentals clo 1.docx

# Networking Fundamentals ## CLO 1 - The internet, which gave rise to - Real-time communications - Global and online communities - Cloud computing ## Network Models - Network model focus on the software side of network implementation: - Type of network operating you are using...

# Networking Fundamentals ## CLO 1 - The internet, which gave rise to - Real-time communications - Global and online communities - Cloud computing ## Network Models - Network model focus on the software side of network implementation: - Type of network operating you are using - Number of user - Skill of the supporting staff ## Host Devices - What are the Host Devices? - Compute able, or smart that are all hosts that are required to for connectivity to - End can be: - Clients: Software requests and displaying information from the server. (Web page from a web server or emails from an email server) - Serve Computers with that allow them to provide to other end the network (Emails, web pages or files) ## Peer-to-peer networks - A P2P network: is one where there is no one device that has complete control of the network and the files, services, and so on that are used on the network. ### Benefits of P2P network model: - Easy to setup - Less complex - Lower cost ### Disadvantages of P2P network model: - No centralized administration - Limited size (Not Scalable) - Slower performance - Poor security ## Intermediary Network Devices - An intermediary device interconnects end devices. Examples of intermediary Devices: - Switches - Wireless access points - Routers - Firewalls. ## Media Types ### Cabled - Guided Network - Coaxial cables (uses electrical impulses) - Twisted pair cables (uses electrical impulses) - Fiber optic cables (uses light pulses) ### Wireless - Unguided Network - Uses modulation of specific frequencies electromagnetic ## Network Topologies - Network Topologies Networks are represented through network diagrams. - Topologies can be divided into two types: - Physical topologies: Describe how the devices are connected. - Logical topologies: Describe how the data travels from device to device. | Type | Physical topology diagrams | Logical topology diagrams | |---|---|---| | Definition | illustrate the physical location of intermediary devices and cable installation. | illustrate devices, ports, and the addressing scheme of the network.| | Example | An image of a network diagram | An image of a network diagram | ## Characteristics of networks involves terminology - The Internet - Intranets - Extranets - The Internet: The services and infrastructure that are publicly available outside of our own networks and the supporting infrastructure. - Intranets: An intranet relates to network communication within our network. - Extranets: Allows access to our intranet to outside organizations. ## Scales of networks - WAN: Wide Area Network - MAN: Metropolitan Area Network - CAN: Campus Area Network - LAN: Local Area Network - PAN: Personal Area Network ## Local Area Networks (LAN) - LAN: Something that covers a geographical area that's small enough that the devices can be classed as being local to each other. - The internal infrastructure for most organizations will normally take the form of a Local Area Network (LAN) ## Wide Area Networks (WAN) - WAN: Something that covers a large geographical area. A WAN is also used to link multiple LANs. ## Implementation Considerations - There are some of the factors that need to be taken into consideration when implementing any network to ensure your network runs efficiently: - Budget - Hardware - Environment - The number of users - Security - Network Model ## Setting up a broadband connection ### Homes users and small offices (SOHO): - Cable - Digital subscriber line (DSL) - Wireless WAN (WWAN) - Mobile services - Dial-up ### Large organizations and Enterprises: - Leased lines - Metro Ethernet - Business DSL - Satellite ## Network Architecture - Network Architecture: The technologies that support the infrastructure that moves data across the network. - The four basic characteristics that the underlying architectures need to address to meet user expectations: - Fault Tolerance - Scalability - Quality of Service (QoS) - Security ### 1. Fault Tolerance - A fault tolerant network limits the impact of a failure by limiting the number of affected devices. - Reliable networks provide redundancy by implementing a Packet switched network: - Packet switching splits traffic into packets that are routed over a network. ### 2. Scalability - A scalable network can expand quickly and easily to support new users and applications without impacting the performance of services to existing users. ### 3. Quality of Service (QoS) - QoS help routers to prioritize network quality. Without QoS, we would get performance quality issues, with buffering occurring ### 4. Network Security - There are two main types of network security: - Network infrastructure security - Physical security of network devices - Preventing unauthorized access to the devices - Information Security - Protection of the information or data transmitted over the network. - Three goals of network security: - Confidentiality: Only intended recipients can read the data. - Integrity: Assurance that the data has not be altered with during transmission. - Availability: Assurance of timely and reliable access to data for authorized users. ## Voice over IP (VoIP) - VoIP requires the support of QoS to operate efficiently in organizations. - Buffering and delay would make two-way communication offered by VoIP and teleconferencing applications impractical. ## The Converging Network - What is a Converging Network? - The provision of telephone, video and data communication services within a single network. ### Before converged networks: - Organization would have been separately cabled for telephone, video, and data. - Each network would use different technologies to carry the signal. - Each technology would use a different set of rules and standards. ## Communication Fundamentals - There are three elements to any communication: - Message source (Sender): Message sources are people, or electronic devices, that need to send a message to other individuals or devices. - Message Destination (Receiver): The destination receives the message and interprets it. - Channel: The media that provides the pathway over which the message travels from source to destination. ## Network Protocol Requirements - Computer protocols must be in agreement and include the following requirements: - Message encoding - Message formatting and encapsulation - Message size - Message timing - Message delivery options ## Network Protocol Functions - What is Network Protocol? - Network protocols define a common set of rules. - Network protocols can be implemented on devices in: - Software - Hardware - Both - Protocols have their own Functions, Format and Rules. | Function | Description | |---|---| | Addressing | Identifies sender and receiver | | Reliability | Provides guaranteed delivery | | Flow Control | Ensures data flows at an efficient rate | | Sequencing | Uniquely labels each transmitted segment of data | | Error Detection | Determines if data became corrupted during transmission. | | Application Interface | Process-to-process communications between network applications | ## Networks require the use of several protocols. | Protocol | Function | |---|---| | Hypertext Transfer Protocol (HTTP) | Governs the way a web server and a web client interact. Defines content and format. Manages the individual conversations. | | Transmission Control Protocol (TCP) | Provides guaranteed delivery. Manages flow control. | | Internet Protocol (IP) | Delivers messages globally from the sender to the receiver. | | Ethernet | Delivers messages from one NIC to another NIC on the same Ethernet Local Area Network (LAN). | ## TCP/IP Protocol - TCP/IP protocols operate at the application, transport, and internet layers. The most common network access layer LAN protocols are: - Ethernet - WLAN (wireless LAN). - TCP/IP is the protocol suite used by the internet and includes many protocols. - Encapsulation: A web server encapsulating and sending a web page to a client. - Decapsulation: A client de-encapsulating the web page for the web browser. ## Open Standards - Open standards encourage: - interoperability - competition - innovation - Standards organizations are: - Vendor-neutral - Non-profit organizations - Established to develop and promote the concept of open standards. - Standards organizations involved with the development and support of TCP/IP include: - IANA - ICANN ## Protocols and Services ### Devices Communication is Legacy Networks: - Systems utilized proprietary software and protocols that would only allow devices communication from the same manufacturer or those manufacturers that had access to those protocols. ### Models providing standard Protocols and Services - The two standard network reference (layered) models that help us to understand communication between network devices: - Open System Interconnection (OSI) Model - TCP/IP Model - The OSI Model created by the International Organization of Standards (ISO) ## OSI Model - What is an OSI Model? A network model comprising seven individual layers. - In the OSI Model, layers communicates to the layers adjacent to it and its equivalent layer on the receiving device. - The top three layers (Application, Presentation, and Session) called The upper layers. - The bottom four layers (Transport, Network, Data-Link, Physical) called The lower layers. | OSI Model Layer | Description | |---|---| | 7 - Application | The application layer contains protocols used for process-to-process communications. | | 6- Presentation | The presentation layer provides for common representation of the data transferred between application layer services. | | 5 - Session | The session layer provides services to the presentation layer to organize its dialogue and to manage data exchange. | | 4 - Transport | The transport layer defines services to segment, transfer, and reassemble the data for individual communications between the end devices. | | 3 - Network | The network layer provides services to exchange the individual pieces of data over the network between identified end devices. | | 2- Data Link | The data link layer protocols describe methods for exchanging data frames between devices over a common media. | | 1 - Physical | The physical layer protocols describe the mechanical, electrical, functional, and procedural means to activate, maintain, and de-activate physical connections for a bit transmission to and from a network device. | ## TCP/IP Model - Understanding the TCP/IP model, will enable you to troubleshoot networking issues on a range of devices. ### TCP/IP model Similarities with OSI model: - They both take on a layered approach, with each layer talking to the adjacent layers and their respective layer on the destination device. - Both models are open or non-proprietary standard, which means any manufacturer can use it. - The TCP/IP model has only four layers: - Application Layer - Transport Layer - Internet Layer - Network Layer ## OSI and TCP/IP Model Comparison | OSI Model | TCP/IP Model | |---|---| | 7 | Application | | 6 | Presentation | | 5 | Session | | 4 | Transport | | 3 | Network | Internet | | 2 | Data Link | Network Access | | 1 | Physical | ## Segmenting Messages - Segmenting: The process of breaking up messages into smaller units. - Multiplexing: The processes of taking multiple streams of segmented data and interleaving them together. - Segmenting messages has two primary benefits: - Increases speed: Large amounts of data can be sent over the network without tying up a communications link. - Increases efficiency: Only segments which fail to reach the destination need to be retransmitted, not the entire data stream. ## Sequencing - Sequencing messages: The process of numbering the segments so that the message may be reassembled at the destination. - TCP is responsible for sequencing the individual segments. ## Protocol Data Units (PDU) - Encapsulation is the process where protocols add their information to the data. - At each stage of the Encapsulation process, a PDU has a different name to reflect its new functions. - PDUs passing down the stack are as follows: 1. Data (Data Stream) 2. Segment 3. Packet 4. Frame 5. Bits (Bit Stream) ## Local Addressing - Identifying devices on a local network can be done using: - Hostnames - MAC addresses - IP addresses - All of these must be unique within the LAN. | | Physical | Data Link | Network | Transport | Upper Layers | |---|---|---|---|---|---| | | Timing and synchronization bits | Destination and source physical addresses | Destination and source logical network addresses | Destination and source process number (ports) | Encoded application data | ### Hostnames - A computer's hostname is an easy-to-read (for humans) method of identifying a device on the network. - When referring to a destination device by its hostname, the sending device will need to resolve it to an IP address. ### IP Addresses - What is an IP Address? An IP address is the network layer (layers 3) or logical address. - IP address is used to deliver packets from source device to destination device. - An IPv4 address is broken down into two sections: - A Network part (IPv4) or Prefix (IPv6): Indicates the network group which the IP address is a member. Each LAN or WAN will have the same network part. - A Host part (IPv4) or Interface ID (IPv6): Identifies a specific device within the group and is unique for each device on the network. ### MAC Addresses - MAC address: A means of identifying a device on the local network. MAC address has many names: - A physical address - Hardware address - Burnt-in address (BIA). - A MAC address is represented as a 48-bit hexadecimal number. ## Physical Layer - What happens in this layer? The physical transmission of the data in the form of bits takes place on this layer. - Physical layer standards include: - Voltages - Speeds - Wiring - Network Interface Card (NIC): Connects a device to the network. - The physical layer transports bits across the network media. - Physical Layer Standards address three functional areas: 1. Physical Components 2. Encoding 3. Signaling ### 1. Physical Components: - The hardware devices, media, and other connectors that transmit the signals that represent the bits. ### 2. Encoding: - Converts the bits into a format 0 1 00 1 1 0 - Examples of encoding method: - Manchester ### 3. Signaling: - The method is how the “1” and are represented on bit values, the physical medium. - The method of signaling will vary based on the type of medium being used. ## Bandwidth - Bandwidth: The capacity at which a medium can carry data. How can we measure bandwidth? - Through Digital bandwidth, it measures the amount of data that can flow from one place to another in a given amount of time, how many bits can be transmitted in a second. | Unit of Bandwidth | Abbreviation | Equivalence | |---|---|---| | Bits per second | bps | 1 bps = fundamental unit of bandwidth | | Kilobits per second | Kbps | 1 Kbps = 1,000 bps = 10^3 bps | | Megabits per second | Mbps | 1 Mbps = 1,000,000 bps = 10^6 bps | | Gigabits per second | Gbps | 1 Gbps 1,000,000,000 bps = 10^9 bps | | Terabits per second | Tbps | 1 Tbps = 1,000,000,000,000 bps = 10^12 bps | ## Bandwidth Terminology 1. LatencX: amount of including delays data to travel from one point to 2. Throughput: measu of transfer of bits the media a the of usable data a given period of tim 3. Goodput: Theasuf - Goodput = Throughput - Traffic overhead ## Characteristics of Copper Cabling - Copper cabling is the most common type of cabling used in networks today. Copper Cabling advantages: - Inexpensive - Easy to install - Low resistance to electrical current flow ## Copper Cabling Limitations: - Attenuation: The longer the electrical signals have to travel, the weaker they get. - The electrical signal is susceptible to interference from two sources, which can distort and corrupt the data signals: - Electromagnetic Interference (EMI) - Radio Frequency Interference (RFI) - Crosstalk ## Copper Cabling Mitigation: - Strict adherence to cable length limits will mitigate attenuation. - Some copper cable mitigates EMI and RFI by using metallic shielding. - Some copper cable mitigates crosstalk by twisting opposing circuit pair wires together. ## Types of Copper Cabling: - Unshielded Twisted-Pair (UTP) - Shielded Twisted-Pair (STP) - Coaxial Cable ## Unshielded Twisted Pair (UTP) - UTP is the most common networking media. Terminated with RJ-45 connectors. - UTP Interconnects hosts with intermediary network devices. ### Key Characteristics of UTP 1. The outer jacket protects the copper wires from physical damage. 2. Twisted pairs protect the signal from interference. 3. Color-coded plastic electrically isolates the wires from each other and identifies each pair. ## Shielded Twisted Pair (STP) - STP Advantages: - Better noise protection than UTP STP - Disadvantages: - More expensive than UTP - Harder to install than UTP - Terminated with RJ-45 connectors. - Interconnects hosts with intermediary network devices. ### Key Characteristics of STP: 1. The outer jacket protects the copper wires from physical damage 2. Braided or foil shield provides EMI/RFI protection 3. Foil shield for each pair of wires provides EMI/RFI protection 4. Color-coded plastic insulation electrically isolates the wires from each other and identifies each pair ## Coaxial Cable - Coaxial Cable consists of the following: 1. Outer cable jacket to prevent minor physical damage 2. Woven copper braid, or metallic foil, acts as the second wire in the circuit and as a shield for the inner conductor. 3. Layer of flexible plastic insulation 4. Copper conductor is used to transmit the electronic signals. ### Types of connectors used with Coaxial Cable: - Coaxial Cable is commonly used in - Wireless installations - attach antennas to wireless devices - Cable internet installations - customer premises wiring ## Straight-through and Crossover UTP Cables | Cable Type | Standard | Application | |---|---|---| | Ethernet Straight-through | Both ends T568A or T568B | Host to Network Device | | Ethernet Crossover * | One end T568A, other end T568B | Host-to-Host, Switch-to-Switch, Router-to-Router | | Rollover | Cisco Proprietary | Host serial port to Router or Switch Console Port, using an adapter | ## Fiber-Optic Cabling ### Properties of Fiber-Optic Cabling: - Not common as UTP because of the expense involved. - Transmits data over longer distances at higher bandwidth than any other networking media. - Less susceptible to attenuation, and completely immune to EMI/RFI. - Made of flexible, extremely thin strands of very pure glass. - Uses a laser or LED to encode bits as pulses of light. ## Types of Fiber Media: ### Single-Mode Fiber - Very small core - Uses expensive lasers - Long-distance applications ### Multimode Fiber - Larger core - Uses less expensive LEDs - LEDs transmit at different angles - Up to 10 Gbps over 550 meters #### What is Dispersion? - Dispersion: The spreading out of a light pulse over time. - Increased dispersion means increased loss of signal strength. - Optical fiber is primarily used as for high-traffic: - Point-to-point connections between data distribution facilities. - Interconnection of buildings in multi-building campuses. ## Fiber vs Copper | Implementation Issues | UTP Cabling | Fiber-Optic Cabling | |---|---|---| | Bandwidth supported | 10 Mb/s - 10 Gb/s | 10 Mb/s - 100 Gb/s | | Distance | Relatively short (1 - 100 meters) | Relatively long (1 - 100,000 meters) | | Immunity to EMI and RFI | Low | High (Completely immune) | | Immunity to electrical hazards | Low | High (Completely immune) | | Media and connector costs | Lowest | Highest | | Installation skills required | Lowest | Highest | | Safety precautions | Lowest | Highest | ## Wireless Media - Wireless media carries electromagnetic signals representing binary digits using radio or microwave frequencies. ### The limitations of wireless: - Coverage area: Effective coverage can be significantly impacted by the physical characteristics of the deployment location. - Interference: Wireless is susceptible to interference and can be disrupted. - Security: Wireless communication coverage requires no access to a physical strand of media, so anyone can gain access to the transmission. - Shared medium: WLANs operate in half-duplex, which means only one device can send or receive at a time. - The IEEE and telecommunications industry standards for wireless data communications cover both the data link and physical layers. - In each of these standards, physical layer specifications dictate: - Data to radio signal encoding methods - Frequency and power of transmission - Signal reception and decoding requirements - Antenna design and construction ## Wireless Standards: - Wi-Fi (IEEE 802.11): Wireless LAN (WLAN) technology. - Bluetooth (IEEE 802.15): Wireless Personal Area network (WPAN) - WiMAX (IEEE 802.16): Uses a point-to-multipoint topology to provide broadband wireless access. - Zigbee (IEEE 802.15.4): Low data-rate, low power-consumption communications, primarily for Internet of Things (IoT) applications. ## Wireless LAN - Wireless LAN (WLAN) requires the following devices: - Wireless Access Point (AP): Concentrate wireless signals from users and connect to the existing copper-based network infrastructure. - Wireless NIC Adapters: Provide wireless communications capability to network hosts. - How to protect WLANs from unauthorized access and damage? - Network Administrators must develop and apply stringent security policies and processes to protect WLANs.