Week 03_CLO2 – Classifying Network Physical Connectivity PDF

CNS 2103: Networking Fundamentals Week 3: CLO2 – Classifying Network Physical Connectivity Delivery Outline 2 Computer Networks W1: CLO1 - Ex...

CNS 2103: Networking Fundamentals Week 3: CLO2 – Classifying Network Physical Connectivity Delivery Outline 2 Computer Networks W1: CLO1 - Explaining modern network technologies principles W2: CLO1 - Explaining network protocols and standards principles W3: CLO2 – Classifying network physical connectivity W4: CLO2 – Implementing media access control, and data link communication W5: CLO2 – Implementing Ethernets, and switched networks W6: CLO3 – Implementing Network layer IP protocols W7-8: CLO3 – Implementing IPv4 subnetting for network segmentation W9: CLO3 – Implementing IPv6 addressing W10: CLO4 – Classifying transport layer protocols operation for end-to-end communication W11: CLO4 – Classifying application layer protocols operation in end-user applications W12: CLO4 – Implementing network hardening features to enhance security W13-14: CLO2-4 – Designing and simulating a small network W15: CLO2-4 – Troubleshooting internetworking Devices Week 3 CLO2 – Physical Layer  Physical Layer 4 Objectives Upon completing this chapter, the learner should be able to: Layer 1 – The Physical Layer. (Chapter 9 of Textbook)  Physical Layer 5 Layer 1 – the Physical Layer The physical transmission of the data in the form of bits takes place on this layer. Depending on the type of media and the network cards in use, the method of sending the data will vary. The important thing is that both ends are using the same method. These signals may be in the form of variations in voltage or patterns in the light being transmitted.  Physical Layer 6 Layer 1 – the Physical Layer At this layer, there are no protocols per second, but there are sets of standards and criteria that the cabling and network cards will need to adhere to. These standards include the following: Voltages Speeds Wiring  Physical Layer 7 The Physical Connection Before any network communications can occur, a physical connection to a local network must be established. This connection could be wired or wireless, depending on the setup of the network. This generally applies whether you are considering a corporate office or a home. A Network Interface Card (NIC) connects a device to the network. Some devices may have just one NIC, while others may have multiple NICs (Wired and/or Wireless, for example). Not all physical connections offer the same level of performance.  Physical Layer 8 The Physical Layer Transports bits across the network media Accepts a complete frame from the Data Link Layer and encodes it as a series of signals that are transmitted to the local media This is the last step in the encapsulation process. The next device in the path to the destination receives the bits and re-encapsulates the frame, then decides what to do with it. Check Your Understanding 1. Login to NetAcad: https://Netacad.com2. Quiz link: https://contenthub.netacad.com/itn-dl/4.1.3  Physical Layer 10 Physical Components Physical Layer Standards address three functional areas: Physical Components Encoding Signaling The Physical Components are the hardware devices, media, and other connectors that transmit the signals that represent the bits. Hardware components like NICs, interfaces and connectors, cable materials, and cable designs are all specified in standards associated with the physical layer.  Physical Layer 11 Encoding Encoding converts the stream of bits into a format recognizable by the next device in the network path. This ‘coding’ provides predictable patterns that can be recognized by the next device. Examples of encoding methods include Manchester (shown in the figure), 4B/5B, and 8B/10B.  Physical Layer 12 Signaling The signaling method is how the bit values, “1” and “0” are Light Pulses Over Fiber-Optic Cable represented on the physical medium. The method of signaling will vary based on the type of medium being used Electrical Signals Over Copper Cable Microwave Signals Over Wireless  Physical Layer 13 Bandwidth Bandwidth is the capacity at which a medium can carry data. Digital bandwidth 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. Physical media properties, current technologies, and the laws of physics play a role in determining available bandwidth. Unit of Bandwidth Abbreviation Equivalence Bits per second bps 1 bps = fundamental unit of bandwidth Kilobits per second Kbps 1 Kbps = 1,000 bps = 103 bps Megabits per second Mbps 1 Mbps = 1,000,000 bps = 106 bps Gigabits per second Gbps 1 Gbps – 1,000,000,000 bps = 109 bps Terabits per second Tbps 1 Tbps = 1,000,000,000,000 bps = 1012 bps  Physical Layer 14 Bandwidth Terminology Latency Amount of time, including delays, for data to travel from one given point to another Throughput The measure of the transfer of bits across the media over a given period of time Goodput The measure of usable data transferred over a given period of time Goodput = Throughput - traffic overhead Check Your Understanding 1. Login to NetAcad: https://Netacad.com2. Quiz link: https://contenthub.netacad.com/itn-dl/4.2.7  Physical Layer 16 Characteristics of Copper Cabling Copper cabling is the most common type of cabling used in networks today. It is inexpensive, easy to install, and has low resistance to electrical current flow. 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) and Radio Frequency Interference (RFI) and Crosstalk). Mitigation: Strict adherence to cable length limits will mitigate attenuation. Some kinds of copper cable mitigate EMI and RFI by using metallic shielding and grounding. Some kinds of copper cable mitigate crosstalk by twisting opposing circuit pair wires together.  Physical Layer 17 Types of Copper Cabling  Physical Layer 18 Unshielded Twisted Pair (UTP) UTP is the most common networking media. Terminated with RJ-45 connectors Interconnects hosts with intermediary network devices. Key Characteristics of UTP The outer jacket protects the copper wires from physical damage. Twisted pairs protect the signal from interference. Color-coded plastic insulation electrically isolates the wires from each other and identifies each pair.  Physical Layer 19 Better noise protection than UTP More expensive than UTP Shielded Twisted Pair (STP) Harder to install than UTP Terminated with RJ-45 connectors Interconnects hosts with intermediary network devices Key Characteristics of STP The outer jacket protects the copper wires from physical damage Braided or foil shield provides EMI/RFI protection Foil shield for each pair of wires provides EMI/RFI protection Color-coded plastic insulation electrically isolates the wires from each other and identifies each pair  Physical Layer 20 Coaxial Cable Consists of the following: Outer cable jacket to prevent minor physical damage A woven copper braid, or metallic foil, acts as the second wire in the circuit and as a shield for the inner conductor. A layer of flexible plastic insulation A copper conductor is used to transmit the electronic signals. There are different types of connectors used with coax cable. Commonly used in the following situations: Wireless installations - attach antennas to wireless devices Cable internet installations - customer premises wiring Check Your Understanding 1. Login to NetAcad: https://Netacad.com2. Quiz link: https://contenthub.netacad.com/itn-dl/4.3.6  Physical Layer 22 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 Host-to-Host, Switch-to-Switch, Router- T568B to-Router * Considered Legacy due to most NICs using Auto-MDIX to sense cable type and complete connection Rollover Cisco Proprietary Host serial port to Router or Switch Console Port, using an adapter Check Your Understanding 1. Login to NetAcad: https://Netacad.com 2. Cable Pinouts Activity: https://contenthub.netacad.com/itn-dl/4.4.4  Physical Layer 24 Properties of Fiber-Optic Cabling Not as common as UTP because of the expense involved Ideal for some networking scenarios 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 The fiber-optic cable acts as a wave guide to transmit light between the two ends with minimal signal loss  Physical Layer 25 Types of Fiber Media Single-Mode Fiber Multimode Fiber Larger core Very small core Uses less expensive LEDs Uses expensive lasers LEDs transmit at different angles Long-distance applications Up to 10 Gbps over 550 meters Dispersion refers to the spreading out of a light pulse over time. Increased dispersion means increased loss of signal strength. MMF has greater dispersion than SMF, with a maximum cable distance for MMF of 550 meters.  Physical Layer 26 Fiber versus Copper Optical fiber is primarily used as backbone cabling for high-traffic, point-to-point connections between data distribution facilities and for the interconnection of buildings in multi-building campuses. Implementation Issues UTP Cabling Fiber-Optic Cabling Bandwidth supported 10 Mb/s - 10 Gb/s 10 Mb/s - 100 Gb/s Relatively short (1 - 100 Relatively long ( 1 - 100,000 Distance meters) 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 Check Your Understanding 1. Login to NetAcad: https://Netacad.com2. Quiz link: https://contenthub.netacad.com/itn-dl/4.5.7  Physical Layer 28 Properties of Wireless Media It carries electromagnetic signals representing binary digits using radio or microwave frequencies. This provides the greatest mobility option. Wireless connection numbers continue to increase. Some of 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 by many common devices. 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. Many users accessing the WLAN simultaneously results in reduced bandwidth for each user.  Physical Layer 29 Types of Wireless Media 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: WiFi (IEEE 802.11) - Wireless LAN (WLAN) technology. Bluetooth (IEEE 802.15) - Wireless Personal Area network (WPAN) standard 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  Physical Layer 30 Wireless LAN In general, a 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 There are a number of WLAN standards. When purchasing WLAN equipment, ensure compatibility, and interoperability. Network Administrators must develop and apply stringent security policies and processes to protect WLANs from unauthorized access and damage. Check Your Understanding 1. Login to NetAcad: https://Netacad.com2. Quiz link: https://contenthub.netacad.com/itn-dl/4.6.4 Test my understanding Module 4 Quiz  Thank You 800 MyHCT (800 www.hct.ac.ae 69428)