Where is the Internet? (2019 Edition)

Mid-semester presentation for my Computers & Society course at Mount Royal University. Has some technical detail about how the internet works, web protocols, data centres, and typical security threats.

Transcript

1. SO WHERE IS THE INTERNET?
2. IT’S NOT HERE
3. It is common to visualize the internet using some type of cloud icon. While convenient, it does hide the fact that the internet is most certainly not composed of magic water vapor, but a whole lot of stuff.
4. WE NEED TO BEGIN HERE …
5. The Internet is composed of millions of kilometers of wires (metal and fiber optic) and millions of computing devices, such as servers, routers, switches, hubs, and other networking devices, most of which is housed in specialized environments requiring countless air conditioners and power devices.
8. The internet is a conglomeration of many different physical networks that are able to communicate thanks to the use of common connection protocols. The internet is built on top of a massive amount of telecommunications infrastructure, most of it initially government-funded, but now generally privately owned.
9. The most important infrastructure belongs to what are commonly called Tier 1 Networks or Tier 1 ISPs. When someone talks about the Internet Backbone, they are talking about Tier 1 networks. About sixteen different companies are considered to be Tier 1 networks, and include Level 3, Tata Communications, NTT, AT&T, and Verizon.
11. Tier 2 Networks may peer for free with some networks but must pay to access at least some other Tier 1 networks (referred to as buying transit). Many regional networks are Tier 2. Some examples include Rogers, Telus, Comcast, British Telecom, and Vodaphone.
12. R O G E R S C A N A D A 2 5 , 0 0 0 K M CENTURYLINK 855,000 KM
15. Since the internet is composed of many interconnected, but independent networks, there needs to be mechanisms for creating those interconnections. Internet Exchange Points (IXPs) have become one of the most important mechanisms for creating those interconnections.
16. An Internet Exchange Point is a physical location where different IP networks and content providers meet to exchange local traffic with each other (that is, peer) via a switch.
18. The internet was designed to be a robust communication network that could continue to work even if parts of the network are disrupted or destroyed. It is the TCP/IP set of protocols that makes this possible. A given message is broken into smaller packets which can take their own independent route from the sender to the destination.
19. Routers are a key technology in the network in that they shuttle packets from one network to another. How are destination computers identified? Each piece of hardware has a unique IP address. Initially each IP address was 12 digits longs. Due to the increase in the number of devices, IP addresses are now substantially longer.
21. I P A D D R E S S E S
22. W h a t a b o u t t h e w e b ?
23. The web uses a client-server model of communication. The client-server model is one in which a computer client, such as a browser, makes requests of another computer called a server, which is normally continually active, listening for requests from clients.
26. HTTP (Hypertext Transfer Protocol) defines a set of rules about how computers communicate with one another. It is actually a simple text-based protocol. While the latest generations of browsers often hide the “http://” in the address bar, HTTP is still present.
27. Other than the fact that almost all web- communication makes use of HTTP, having some idea about how HTTP works can help you in understanding many of the constraints that exist within the field of web development, and many of the security problems that bedevil the web space.
30. What about HTTPS? HTTP Secure (sometimes also called, more long-windely, as HTTP over Transport Layer Security). This protocol is essentially identical to HTTP except the connection content is also encrypted. It protects against man-in-the- middle attacks, so that an eavesdropper on a session can not read or tamper with it.
31. In some of the earlier diagrams, the server was represented as a single entity. This is in fact quite misleading. A typical website makes use of several, dozens, hundreds or even hundreds of thousands of servers. Why?
32. Partly this is for functional reasons: different types of tasks will be isolated in different servers. Partly this is for performance reasons: a single server has limits to how many simultaneous requests it can manage. Another important reason is for redundancy: computers do fail and so having multiple servers ensures a service works even when a single server stops working.
34. Server farms are typically housed within specialized facilities known as data centers. These facilities contain a lot more than just lots of computers contained within server racks.
37. All those computers will generate a great deal of heat, and so a key component of a data center will be its heat generation counter-measures. These include reliable air conditioning, forced air recirculation, and using chilled water directly within the server racks.
40. Reliable and even power is the other key component of any data center. This will be achieved via UPS and other devices to normalize electrical power as well as diesel generators and DC battery supplies to preserve electrical power even during power outages.
43. Data centers in 2013 consumed somewhere between 2% to 4% of the entire United States electrical consumption. Data centers in Ireland in 2016 consumed about 20% of Ireland’s entire electrical consumption.
44. Computing in general in 2012 consumed somewhere about 5% of the world’s electricity. Optimistic Estimate: by 2025, computing will consume 20% of world-wide electricity. In 2016 about 11% of all global electricity was consumed by computing.
45. Computing will soon produce about 3% of global carbon emissions. Optimistic Estimate: Within a decade, computing will produce about 14% of global carbon emissions.
46. “The analysis shows that for the worst-case scenario, CT could use as much as 51% of global electricity in 2030. … the present investigation suggests, for the worst case scenario, that CT electricity usage could contribute up to 23% of the globally released greenhouse gas emissions in 2030.”
47. In 2011, Google reported its energy consumption to be 230 MWh. In 2014, it reported 3.2 GWh (i.e. 3200 MWh) even though it had made many of its data centers significantly more energy efficient. How is this possible?
48. Governments and environmentalists generally assume that improving the energy efficiency of a process will lower its resource consumption. Yet in economics, the Jevons Paradox argues that the opposite will often occur.
49. In economics, the Jevons paradox occurs when technological progress increases the efficiency with which a resource is used (reducing the amount necessary for any one use), but the rate of consumption of that resource rises because of increased demand due to falling prices.
50. Thus, the dramatic improvements of energy efficiency in data centers in recent years has actually increased the amount of energy being consumed in data centers (because improved energy efficiency has lowered costs thereby encouraging more people to make use of data centers).
51. Estimate: 550GWh of power consumed just to serve these 3 billion views (YouTube servers+downloads+views) … roughly equal to Canada’s yearly energy consumption)
52. But what about energy savings as a result of the displacement of older technologies with newer computing-based ones?
53. One study, for instance, that examined the total energy footprint of a paper newspaper compared to its online version found that paper version consumed about half as much energy (and that study didn't even factor in data center energy consumption).
54. However, a different study examining energy consumption of rented DVDs vs streamed movies found a reduction in the total energy footprint with the switch to streaming (however that study also didn't factor in data center energy consumption).
56. DEPLOYMENT VIRTUALIZATION A N D
57. D E D I C AT E D H O S T I N G Each site is on its own server(s)
58. S I M P L E S H A R E D H O S T I N G
59. V I RT U A L S H A R E D H O S T
60. C L O U D H O S T I N G
61. W h y C l o u d H o s t i n g ? R e d u n d a n c y 01 O n - D e m a n d P r o v i s i o n i n g 02 S c a l a b i l i t y 03 C o s t E f f i c i e n c y 04 L o w S t a r t u p C o s t s 05 M a n a g e r s S e e m t o L o v e C l o u d s … 06
62. HOW?
63. S E RV E R I N E F F I C I E N C I E S
64. H O W I T W O R K S
65. C l o u d S e r v i c e M o d e l s C l o u d c o m p u t i n g p r o m i s e s s o m e t h i n g u s u a l l y r e f e r r e d t o a s e l a s t i c c a p a c i t y / c o m p u t i n g , m e a n i n g t h a t s e r v e r c a p a b i l i t y c a n s c a l e w i t h d e m a n d . Platform as a Service (PaaS) Infrastructure as a Service (IaaS) Software as a Service (SaaS) Amazon Web Services Microsoft Azure Google Cloud Platform
66. Security and Search
67. T H E P R O B L E M W I T H E V E
68. U S I N G E N C RY P T I O N
69. P R O B L E M : H O W T O T R A N S P O R T K E Y
70. S I M P L E E N C RY P T I O N E X A M P L E
71. H T T P S Q U I C K LY
72. S E C U R I T Y T H R E AT S
73. S Q L I N J E C T I O N AT TA C K
74. C R O S S - S I T E S C R I P T I N G AT TA C K
75. D E N I A L O F S E RV I C E AT TA C K
76. R A I N B O W TA B L E AT TA C K ( C O N T E X T )
77. R A I N B O W TA B L E AT TA C K ( S O L U T I O N ? )
78. R A I N B O W TA B L E AT TA C K ( S O L U T I O N ! )