306 DB points
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Information Systems:
A Manager’s Guide to Harnessing Technology
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Chapter 12
A Manager’s Guide to The Internet and Telecommunications
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Learning Objectives
- Describe how the technologies of the Internet combine to answer the questions: What are you looking for? Where is it? And how do we get there?
- Interpret a URL, understand what hosts and domains are, describe how domain registration works, describe cybersquatting, and give examples of conditions that constitute a valid and invalid domain-related trademark dispute
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Learning Objectives
- Describe certain aspects of the Internet infrastructure that are fault tolerant and supports load balancing
- Discuss the role of hosts, domains, IP addresses, and the DNS in making the Internet work
- Understand the layers that make up the Internet – application protocol, transmission control protocol, and internet protocol – and describe why each is important
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Learning Objectives
- Discuss the benefits of Internet architecture in general, and TCP/IP in particular
- Name applications that should use TCP, and others that might use UDP
- Understand what a router does, and the role these devices play in networking
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Learning Objectives
- Conduct a traceroute and discuss output, demonstrating how Internet interconnections work in getting messages from point to point
- Appreciate why mastery of Internet infrastructure is critical to modern finance, and be able to discuss the risks in automated trading systems
- Describe VoIP, and contrast circuit vs. packet switching, along with organizational benefits and limitations of each
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Learning Objectives
- Understand the last mile problem, and be able to discuss the pros and cons of various broadband technologies including DSL, cable, fiber, and various wireless offerings
- Describe 3G and 4G systems, listing major technologies and their backers
- Understand the issue of net neutrality and put forth arguments supporting or criticizing the concept
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Figure 12.1 – The Internet is a network of networks, and these networks are connected together
- The Internet is a network of millions of networks
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Figure 12.2 – Anatomy of a Web Address
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The Web Address
- Hypertext transfer protocol (http) - application transfer protocol that allows web browsers and web servers to communicate
- A domain name represents an organization and a host refers to public services offered by that organization
- Host and domain names are case-insensitive
- Path maps to folder location where file is stored on server
- Path and filenames are case sensitive
- Filename refers to name of file stored on server
Item Number: 101783940
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Host and Domain Names: A Bit More Complex Than That
- A domain name represents an organization
- Hosts are public services offered by that organization
- Load Balancing: Distributing a computing or networking workload across multiple systems in order to avoid congestion and slow performance
- Fault Tolerant: Systems that are capable of continuing operation even if a component fails
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I Want My Own Domain
- One can register a domain name, paying for a renewable right to use that domain name
- Domain name registration is handled on a first-come, first-served basis and all registrars share registration data to ensure that no two firms gain rights to the same name
- Cybersquatting: Acquiring a domain name that refers to a firm, individual, product, or trademark, with the goal of exploiting it for financial gain
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IP Addresses and the Domain Name System
- Every device connected to the Internet has an identifying address called the Internet Protocol (IP) address
- The domain name service is hierarchical system of nameservers that maps host-domain name combinations to IP addresses
- The cache is a temporary storage space that speeds up IP address mapping by avoiding nameserver visits
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Figure 12.3 – When your Computer needs to find the IP address for a host or domain name, it sends a message to a DNS resolver, which looks up the IP address starting at the root nameserver
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The Internet is Almost Full
- Inefficient allocation of IP addresses and exploding number of Internet connected devices means that we’re running out of IP addresses
- Shifting to a new IP scheme such as IPv6 increases the possible address space to a new theoretical limit of 2128 addresses
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TCP/IP – The Internet’s Secret Sauce
- The Internet Protocol Suite consists of:
- Transmission Control Protocol (TCP)
- Internet Protocol (IP)
- TCP works at both ends of Internet communications to ensure perfect copies of messages are sent
- IP is a routing protocol in charge of forwarding packets on the Internet
- Routers are computing devices that connect networks and exchange data between them
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Figure 12.4 – TCP/IP in Action
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Routers
- Routers are special computing devices that forward packets from one location to the next
- Routers are typically connected with more than one outbound path, so that in case one path becomes unavailable, an alternate path can be used
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UDP: TCP’s Faster, Less Reliable Sibling
- TCP is a perfectionist and this is essential for web transmissions, e-mail, and application downloads
- Streaming media applications like Internet voice chat and video conferencing require sacrificing of perfection for speed
- User Datagram Protocol (UDP) works as a TCP stand-in speed is needed and quality has to be sacrificed
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VoIP
- Old phone systems use circuit switching for a dedicated connection between two entities
- Internet networks are packet switched and conversations are sliced into packets and squeezed into smaller spaces
- VoIP allows voice and phone systems to become an application traveling over the Internet
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Finance has a Need for Speed
- Electronic trading systems leverage data mining and other techniques to crunch massive volumes of data and discover exploitable market patterns
- Models are then run against real-time data and executed the instant a trading opportunity is detected
- Systems that run on their own can move many billions instantly, and the actions of one system may cascade, triggering actions by others
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Watching the Packet Path via Traceroute
- Traceroute sends clusters of three packets starting at first router connected to a computer, then the next, and so on, building out paths packets take to their destination
- Some networks block traceroute because hackers have used the tool to probe a network to figure out how to attack an organization
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What Connects the Routers and Computers?
- Computers are connected to the Internet by:
- Copper cable, for short distances
- Fiber optic lines, for long distances
- Wireless
- TCP/IP is not dependent on transmission media
- Most Internet communications are carried out via a combination of transmission media
Item number: 92041959
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Last Mile: Faster Speed, Broader Access
- The Internet Backbone, made of fiber optic lines, is very fast
- Amdahl’s law sates that a system’s speed is determined by its slowest component or the last mile
- High-speed last mile technologies are often referred to as Broadband Internet Access
- Various technology upgrades are happening to speed up last mile connectivity
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Cable Broadband
- Majority of domestic broadband connections are through copper cable technology
- Coaxial copper cables have shielding to reduce electrical interference
- Signals travel longer distances without degrading and at significant speeds
- Fiber/optic hybrid based networks are expensive, but offer higher speeds
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DSL – Phone Company Copper
- DSL technology uses copper wire phone companies have already run into homes
- Unlike cable, DSL uses standard copper wiring without shielding
- Signals degrade with distance from phone company offices
- DSL technology is popular in Europe and Asia owing to densely populated cities
- DSL connections are infeasible in the U.S. where cities are sparsely populated
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Fiber – A Light-filled Glass Pipe to your Doorstep
- FTTH or Fiber to the Home is the fastest last mile technology around
- FTTH networks need to be built from scratch as they do not have preexisting infrastructure
- However, FTTH can be profitable as it supports a wide range of services
- Many ISPs like Google and Verizon have made multibillion investments in FTTH for experimental and business reasons, respectively
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Wireless
- Mobile wireless service is provided to customers via cell towers
- With boom in sales of smart phones, bandwidth crunch is becoming a serious concern for ISPs
- Wireless networks are transitioning from third generation (3G) to fourth generation (4G)
- 3G networks are slower than 4G and offer a lesser range of services
Item number: 94099985
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3G standards
- 3G standards are divided along two camps:
- Global System for Mobile Communications (GSM)
- Code Division Multiple Access (CDMA)
- The GSM standard is the most used around the world
- CDMA is limited by its inability to support voice and data communication at the same time
Item number: 95207220
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4G standards
- 4G standards are divided along the lines of:
- Long Term Evolution (LTE)
- Worldwide Interoperability for Microwave Access (WiMax)
- DSL, cable, and fiber firms could be affected by 4G implementations
- 4G offers them option of entering mobile phone business and offer a wider range of services
- If speeds of 4G networks increase, more users could switch from cable, DSL, and fiber to wireless Internet access
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Satellite Wireless
- Early satellite based telecommunications services suffered from problems such as:
- Download-only capability
- Required expensive and bulky equipment
- High latency
- O3b networks has offered to provide fiber-quality broadband access
- O3b plans to use a network of middle earth orbit satellites to reduce latency
- If O3b’s efforts are successful, it could transform the broadband industry
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Wi-Fi and other hotspots
- Computer and mobile devices have Wireless Fidelity antennas built into their chipsets
- To connect to the Internet, a device needs to be within range of a base station or hotspot
- Cell coverage is often limited due to lack of service towers
- Fentocells are being offered to improve wireless reception
Item number: 97889798
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Net Neutrality- What’s Fair?
- Net neutrality is the principle that all Internet traffic should be treated equally
- Many ISPs offer varying coverage, depending on service used and bandwidth consumed
- Internet firms say it is vital to maintain the openness of the Internet
- Telecommunications firms say they should be able to limit access to services that overtax their networks
- Another concern for service providers is ever-increasing demand for greater bandwidth