Chapter 12 A Manager s Guide to The Internet and Telecommunications 1 1 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 1 2 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 1 3 Learning Objectives Discuss the benefits of Internet architecture in general TCP IP in Name applications that should use TCP and others that might use Understand what a router does and the role these devices play in particular UDP networking 1 4 Learning Objectives Describe VoIP contrast circuit vs packet switching along with organizational benefits and limitations of each 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 1 5 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 1 6 Figure 12 2 Anatomy of a Web Address 1 7 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 1 8 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 1 9 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 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 1 10 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 1 11 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 1 12 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 1 13 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 1 14 Figure 12 4 TCP IP in Action 1 15 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 1 16 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 1 17 VoIP Old phone systems use circuit switching for a dedicated connection between two entities Internet networks are packet switched where conversations are sliced into packets and squeezed into smaller spaces VoIP allows voice and phone systems to become an application traveling over the Internet 1 18 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 1 19 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 1 20 Cable Broadband Majority of domestic broadband connections are through copper cable technology interference significant speeds Coaxial copper cables have shielding to reduce electrical Signals travel longer distances without degrading and at Fiber optic hybrid based networks are expensive but offer higher speeds 1 21 DSL Phone Company Copper DSL technology uses copper wire that 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 sparsely populated DSL
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