Lecture 3 (Wireless & Cloud Computing) Lecture Notes PDF

# Telecommunications & Networking Chapter 6 ## Network - Connect data and info through a network - Enable organizations to adapt to rapidly changing business conditions. - Enables organizations to share hardware, applications, and data across the org. and among orgs. - Enable geographically disper...

# Telecommunications & Networking Chapter 6 ## Network - Connect data and info through a network - Enable organizations to adapt to rapidly changing business conditions. - Enables organizations to share hardware, applications, and data across the org. and among orgs. - Enable geographically dispersed employees to work together. - Networks are critical links between orgs., their partners, and their customers. - Employees in different countries can connect remotely through a network. ## Computer Network - A computer network is a system that connects computers and other devices (e.g., printers) through communications media so that data and information can be transmitted among them. - Common Types of Computer Networks include: - Local Area Network (LAN) - Wide Area Network (WAN) ### 1. Local Area Network (LAN) - Connects two or more devices in a limited geographical region, usually within the same building. - The ownership of the network is private. - Every device in the LAN has a network interface card (NIC) that allow the device to physically connect to the LAN. ### 2. Wide Area Network (WAN) - A network that covers a large geographical area. - WANs typically connect multiple LANs. - They have large capacity and are generally provided by common carriers such as telephone companies and international telecommunication services providers. - The Internet is an example of a WAN. - The ownership of the network could be private or public. ## Key Terms - **Internet:** (Building block of network) - A global network that connects millions of computer networks including devices such as smartphones, PCs, mainframe computers etc. - **Intranet:** The use of internet inside an organization. - The use of internet technology inside organizations. - Example: The university has an intranet that you use as a student intranet to access the university materials or apps. - **Extranet:** - Connects organizations' intranets to each other if they are business partners. - **Bandwidth:** How fast data can be transmitted to a network. - Refers to the transmission capacity of a network; it is stated in bits per second (bps). - Bandwidth ranges from narrowband (relatively low transmission capacity) to broadband (relatively high network capacity). - A broadband connection means a "Fast" connection. ## Communications Media & Channels - A communication channel is a pathway or medium for delivering data from one computing device to another. - Two types of media: - Cables (i.e., uses physical wires). - Wireless (i.e., does not require physical wires). ## Different types of Cables - **a) Twisted Pair Wire (Copper Wire)** - Very cheap. - Easy to break and cut. - **b) Coaxial Cable (Copper Wire)** - Has great broadband (can transmit data faster) - **c) Fiber Optics (Glass)** - Expensive - Fastest communication media. Even telecom use it. - If you break it, you cannot splice. ## Network Protocols - **Protocol:** - The set of rules and procedures governing transmission of data across a network. - Two major types: - Ethernet: Common protocol for Local Area Network (LAN). - TCP/IP: Protocol of the Internet (using webbrowser (note: you can learn more about it from the textbook if you wish)). - **Ex:** Voicecall. / Facetime, you are transmitting voice. - **Most important:** Transmits data from one to another. - Responsible down data to smaller packets and sending them over (TCP). - Actually sending the message over (IP). ## Wireless Technologies - Any tech that can send and receive data over a network without cables. ## The Internet of Things (IoT) - Things or objects that share data without the need for physical human interactions. - **Ex:** cars, apple watches. - **Internet of Things (IoT):** A system of interrelated computing devices, mechanical and digital machines, objects, animals or people that are provided with unique identifiers (aka sensors) and are able to transfer data wirelessly over a network without requiring human-to-human or human-to-computer interaction. - **A thing in the IoT** can be a person with a hear monitor implant, a farm animal with a biochip transponder, an automobile that has built-in sensors to alert the driver when tire pressure is low or any other natural or man-made object that can be assigned an IP address and is able to transfer data over a network. - This continuous connection or presence over the internet from any location using any device is called **Ubiquitous Computing**. - **Examples:** Smart health, smart TV, smart home, apple watches. ## Issues - **Security:** Because IoT devices are closely connected, all a hacker has to do is exploit one vulnerability to manipulate all the data. - Manufacturers that don't update their devices regularly - or at all - leave them vulnerable to cybercriminals. - **Privacy:** Is another major concern for IoT users. For instance, companies that make and distribute consumer IoT devices could use those devices to obtain and sell users' personal data. - **Challenges with IoT:** - Reliability and stability - of IoT sensors. - Maintenance. ## Cloud Computing - **IT components:** Hardware, Software, Networks, Databases, IT services-developing systems. - One of the top platforms to build websites. - **Traditional IT Infrastructure** - **On-Premise Computing:** A type of IT model where a company owns its IT infrastructure (hardware, software, networks, and data management) and maintains the physical existence of this infrastructure internally (i.e., onpremise). ## Problems - Puts a lot of pressure to be more flexible. - It doesn't allow them to change. - It can cost a lot to change and maintain them. - **Globalization:** IT must meet the business needs to serve customers world-wide, round the clock - 24x7x365. - **Aging Data Centers:** Migration, upgrading technology to replace old technology. - **Storage Growth:** Explosion of storage consumption and usage. - **Application Explosion:** New applications need to be deployed and their usage may scale rapidly. The current data center infrastructures are not planned to accommodate for such rapid growth. - **Cost of ownership:** Due to increasing business demand, the cost of buying new equipment, power, cooling, support, licenses etc., increases the Total Cost of Ownership (TCO). - **Acquisitions:** When companies are acquired, the IT infrastructures of the acquired company and the acquiring company are often different. These differences in the IT infrastructures demand significant effort to make them interoperable. ## Solutions - From traditional (onpremise) → cloud - This allows other companies to access these services remotely. - This is called **Virtualization**. - The company no longer owns the physical, but they can share the access. ## What Is Cloud Computing? - Cloud computing is a general term for anything that involves delivering hosted services over the internet. - They are hosted on **virtualized servers** (e.g., server farms / data centers). - The name "cloud computing" was inspired by the cloud symbol that's often used to represent the internet in flowcharts and diagrams. - Cloud computing uses the internet and remote computing to deliver convenient, on-demand, pay-as-you-go access for multiple customers to a shared pool of computing resources. - These resources include servers, networks, storage, applications, and services. - **Servers:** Large multi-user computers used to store applications and data (Ex: Amazon). - With Amazon, you can just download the app and all you need is the internet. - Smaller companies may own their own/rent server capacity from bigger organizations. ## Servers! - Computing hardware resources are located in server farms. ## Example: Uwindsor Email - You don't need to buy a server. The application you need is in a server, but you don't need a physical one. All you need is the internet. - So where is the email application then? - It is hosted on servers in a server farm or a data centre (i.e., cloud) either owned and managed by University of Windsor or Microsoft. - But we do not care where it is hosted. We just care that we access it. ## What happens when you click a link or website? 1. **Request:** - Tell the web browser the web page you want to visit by typing its Uniform Resource Locator (URL) e.g., https://www.uwindsor.ca. 2. **The browser:** - Checks the prefix of the URL (usually https:// or http:// - both of which indicate that the resource is a web page. - Gets the URL's domain name "the something.com." or "whatever.org." part- and translates this into a unique location - called the IP (internet protocol) address so that the web server that hosts the page can understand which page it should render to the user. - **Remember!** The computer does not understand our language! But only Os & 1s. 3. **The browser contacts the web server and requests the web page:** - With the web server's unique IP address in hand, the web browser sets up a communications channel with the server and then uses that channel to send along a request for the web page. 4. **The web server encodes the page request:** - The server uses the page address to find the directory that holds the page and the file in which the page code is stored. 5. **The web server sends the web page file to the web browser.** 6. **The web browser decodes the web page file:** - Decoding the page file means looking for text to display, instructions on how to display that text, and other resources required by the page, such as images and fonts. ## Different Types of Clouds - **Public Clouds:** - Shared, easily accessible, multi-customer IT infrastructures that are available nonexclusively to any entity in the general public (individuals, groups, and/or organizations). Public cloud vendors provide applications, storage and other computing resources as services over the internet (e.g., Google). - **Private Clouds:** - Also known as internal clouds or corporate clouds IT infrastructures accessed only by a single entity or by an exclusive group of related entities that share the same purpose and requirements, such as all of the business units within a single organization. - **Ex:** Uwindsor WIFI - Enterprises adopt private clouds to ensure system and data security. For this reason, these systems are implemented behind the corporate firewall. - **Hybrid Clouds:** - Composed of public and private clouds offering users the benefits of multiple deployment models. Hybrid clouds deliver services based on security requirements, the nature of the applications, and other company-established policies. ## Cloud Computing Services ### a) Infrastructure-as-a-Service (IaaS) - Cloud computing providers offer remotely accessible servers, networks, and storage capacity. - **Pay another company to get access to networks.** - They supply these resources on demand from their large resource pools, which are located in their data centers. ### b) Platform-as-a-Service (PaaS) - Customers rent servers, network capacity, storage, operating systems, Java. - Allows customers to run existing apps and develop and test new apps without the cost of buying and managing hardware and software. ### c) Software-as-a-Service (SaaS) - Cloud computing vendors provide software that is specific to their customers' requirements. - SaaS is the most widely utilized service model and it provides a broad range of software applications. - SaaS providers typically charge their customers a monthly or yearly subscription fee. - **Virtualization** - SaaS applications reside in the cloud instead of on a user's hard drive or in a data center. ## Comparison of on-premise software, infrastructure-as-a-service, platform-as-a-service, and software-as-a-service. | **On-premise software** | **Infrastructure-as-a-service** | **Platform-as-a-service** | **Software-as-a-service** | |---|---|---|---| | **Customer manages** | **Vendor manages** | **Vendor manages** | **Vendor manages** | | Applications | Applications | Applications | Applications | | Data | Data | Data | Data | | Operating system | Operating system | Operating system | Operating system | | Servers | Servers | Servers | Servers | | Virtualization | Virtualization | Virtualization | Virtualization | | Storage | Storage | Storage | Storage | | Networking | Networking | Networking | Networking | | Examples | Amazon, IBM, Google, Microsoft, Rackspace | Microsoft Windows Azure, Google App Engine, Force.com | Salesforce.com, Google Apps, Dropbox, Apple iCloud, Box.net | ## The Big 4 Cloud Computing Vendors 1. Amazon 2. Microsoft Azure 3. Google Cloud 4. IBM ## Cloud Computing Characteristics - **Provides on-demand self-service** where customers can access needed computing resources automatically. - **Enables organizations to utilize resources more efficiently** (saves lots of money & maintenance). - **Provides fault tolerance** (i.e., there is no single point of failure, so the failure of one computer will not stop an application from executing). - **Makes it easy to scale up:** The ability to access increased computing resources (i.e., add more servers) - to meet the processing demands of complex applications. - **Makes it easy to scale down:** Organizations can easily remove computers if extensive processing if not needed.