-
Notifications
You must be signed in to change notification settings - Fork 1
/
mod1-01.html
589 lines (526 loc) · 29.7 KB
/
mod1-01.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Advanced Networking - Module 1 Chapter 1 - Exploring the Network</title>
<meta name="description" content="Abilitante alle certificazioni Cisco CCENT e CCNA">
<meta name="author" content="Hacklab Cosenza">
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
<link rel="stylesheet" href="css/reveal.css">
<link rel="stylesheet" href="css/theme/hlcs.css" id="theme">
<!-- Code syntax highlighting -->
<link rel="stylesheet" href="lib/css/zenburn.css">
<!-- Printing and PDF exports -->
<script>
var link = document.createElement( 'link' );
var link = document.createElement( 'link' );
link.rel = 'stylesheet';
link.type = 'text/css';
link.href = window.location.search.match( /print-pdf/gi ) ? 'css/print/pdf.css' : 'css/print/paper.css';
document.getElementsByTagName( 'head' )[0].appendChild( link );
</script>
<!--[if lt IE 9]>
<script src="lib/js/html5shiv.js"></script>
<![endif]-->
</head>
<body>
<div class="reveal">
<!-- Any section element inside of this container is displayed as a slide -->
<div class="slides">
<section>
<h1>Advanced Networking</h1>
<h2>Routing & Switching:</h2>
<h2>Introduction to Networks</h2>
<h3>Chapter 1: Exploring the Network</h3>
<small><a href="http://hlcs.it">Hacklab Cosenza</a> / Centro di Ricerca su Tecnologia e Innovazione</small>
</section>
<!--
<section>
<section>
<h2>What this 1st chapter is about</h2>
<p>Realize the significance of what we're trying to do here, really.</p>
<p>By the way, The Internet is <strong>awesome</strong>. Did you notice?</p>
<p>Here's an awesome fact about the Internet: news about earthquakes can <em>overtake</em> them.</p>
</section>
<section>
<img src="http://imgs.xkcd.com/comics/seismic_waves.png">
<p>Please do not tweet about earthquakes during earthquakes.</p>
</section>
</section>
<section>
<section>
<h2>(Very) Short story of the Internet</h2>
<ul>
<li>Someone very clever built a very smart communication system.</li>
<li>They had a reason</li>
<li>Even smarter people started using it for all kinds of <em>different</em> reasons. And then some more.</li>
</ul>
</section>
<section>
<h2>(Very) Short profile of the Internet</h2>
<p>As an invention, the Internet is both an <strong>enabler</strong> and an <em>amplifier</em>. Almost never in a predictable way.</p>
<p>As developers of networks, by pushing the limits of the network we design, we <em>enable</em>. To what, it's for our users to figure out.</p>
<p>The improvements we make in terms of <strong>speed, features, stability, security, easyness of use, and more</strong> directly or indirectly <em>amplify</em> the scope of the Internet as an invention.</p>
</section>
</section>
-->
<section>
<h2>Internet of Things (IoT)</h2>
<!-- <p><iframe src="http://player.vimeo.com/video/94011734" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe></p> -->
<img src="https://i.imgur.com/UcJ1jZ2.png">
<!-- DEAD LINKS -->
<!-- <small>Infographic by <a href="http://www.theconnectivist.com/2014/05/infographic-the-growth-of-the-internet-of-things/">The Connectivist</a> // <a href="http://vimeo.com/94011734">Video</a></small> -->
</section>
<section>
<h2>IoT: How did we get here?</h2>
<ul>
<li>We used to <strong>go to the connected device</strong>. Think PCs.</li>
<li>Now we bring our <strong>own device with us, and it connects us</strong>. Think Smartphones, tablets.</li>
<li>Soon you won't feel any difference, because <strong>everything will be a connected device</strong>.</li>
<li>And then? Cisco thinks everything and everyone, material and asbtract, will be connected, and calls this <strong><em>Internet of Everything</em></strong>.</li>
<p><u>Beware</u>: Cisco has its own term for <em>anything</em>. No, seriously.</p>
</ul>
</section>
<!--
<section>
<h2>The Human Network</h2>
<p>Think for 1 minute about how much just the first 25 years of the Internet have changed, and then for another minute about what <strong>the impact of the next 25 years</strong> could possibly be.</p>
<p>Cisco calls the study of such an impact networks can make on people, businesses, ideas, the <strong><em>Human Network</em></strong>.</p>
<p>You were warned about Cisco and terminology, weren't you?</p>
</section>
<section>
<h2>Impact on how we learn</h2>
<p>This would be you, by the way.</p>
<p>First of all, just look at the sheer <strong>amount of material</strong>: it's self-learning paradise.</p>
<p>We have grown out of textbook, schedule, teachers: <strong>audio, video and interactivity</strong> mean we can learn about anything, anywhere, on our own pace, and reach any level we want to.</p>
<p>No fixed roles, <strong>you can contribute</strong> back: the only thing stopping you from sharing your knowledge with the same effectiveness, is an internet connection.</p>
</section>
<section>
<h2>MOOC: Massive Open Online Course</h2>
<p>or: <em>Let's graduate at MIT for free!</em>. Kind of.</p>
<img src="https://i.imgur.com/ET8z7Qq.png" style="width: 50%; height: 50%;">
</section>
<section>
<h2>Impact on how we communicate</h2>
<p>There's been a switch on the Internet, that is long completed: from Web 1.0 (the content is provided to us) to <strong>Web 2.0 (User Generated Content, UCG)</strong>.</p>
<img src="http://upload.wikimedia.org/wikipedia/commons/b/bb/Herramientas_web_2.0.jpg">
<p>Some of the keywords for the Web 2.0: <strong>Social Media, Istant Messaging, Podcasting, File Sharing, Blog, RSS</strong>.</p>
</section>
<section>
<h2>Impact on how we work</h2>
<p>An ever increasing number of <strong>people can work from home</strong> thanks to the improved capabilities of networks and the quality of the tool at their disposal.</p>
<p>For many tasks, you went from needing several tools, persons and facilities, to <strong>just one</strong>: a network connection.</p>
<iframe src="http://player.vimeo.com/video/107569286?loop=1" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
<small><a href="http://vimeo.com/107569286">the evolution of the desk</a> by <a href="http://www.designboom.com/technology/evolution-desk-harvard-innovation-lab-09-30-2014/">the harvard innovation lab</a>.</small>
</section>
<section>
<h2>Impact on how we're entertained</h2>
<p>More videos of cute cats and dogs than you need in a lifetime. It's also worth mentioning:</p>
<ul>
<li>Throw <strong>your destination at your phone</strong> and see what happens.</li>
<li>5D Graphics are worthless if you can't do <strong>online gaming / multiplaying</strong>.</li>
<li>Any niche market, no matter how small, can prosper with <strong>eCommerce and online payments</strong>.</li>
</ul>
</section>
-->
<section>
<h2>All sizes of Networks</h2>
<ul>
<li><strong>Small networks</strong>: think about your home setup to connect to the Internet.</li>
<li><strong>Small Office/Home Office (SOHO)</strong>: multiple computers and dedicated devices connecting to centralized resources for business purposes.</li>
<li><strong>Medium/Large Networks</strong>: multiple locations connecting hundreds/thousands computers.</li>
<li><strong>World Wide Networks</strong>: well, the Internet.</li>
</ul>
<p><strong>Internet is literally <em>Network of Networks</em></strong>. It's the largest network there is.</p>
</section>
<section>
<h2>Client-Server</h2>
<img src="https://i.imgur.com/QIkKReA.gif">
<ul>
<li><strong>Host</strong>: generic name for a device that participates in a network's communications.</li>
<ul>
<li>also called: <em>end devices</em> or <em>endpoints</em>.</li>
</ul>
<li><strong>Server</strong>: hosts that <em>provide</em> information through server software.</li>
<li><strong>Client</strong>: hosts that <em>request and display</em> this information through client software.</li>
</ul>
</section>
<section>
<h2>Client-Server: no clear-cut</h2>
<ul>
<li>One host can be <strong>both</strong> a client and a server.</li>
<li>Multiple <strong>kinds of informations</strong> provided or requested at the same time.</li>
<li>Server functions are usually logically grouped, while clients are <strong>general purpose</strong>.
</ul>
</section>
<section>
<h2>Peer to Peer (P2P)</h2>
<img src="https://i.imgur.com/Ivxn10D.png" style="background: white; width: 320px; height: 240px;">
<p>A network where hosts acts simultaneously as client and server for a specific type of information is called a <strong>Peer to Peer</strong> network.</p>
<p>This is much more a <strong>software</strong> distinction.</p>
</section>
<section>
<h2>Peer to Peer (P2P)</h2>
<h3>Advantages</h3>
<ul>
<li>Easy configuration</li>
<li>Less complexity</li>
<li>Lower cost, doesn't need dedicated devices</li>
<li>Better for simple tasks</li>
</ul>
<h3>Disadvantages</h3>
<ul>
<li>No centralized administration</li>
<li>Security</li>
<li>Scalability</li>
<li>Slow performances of devices.</li>
</ul>
</section>
<section>
<h2>Network Components</h2>
<p>Every network infrastructures has components that falls in one of these 3 categories:</p>
<ul>
<li><strong>Devices</strong> (router, servers, laptops, printers, etc.)</li>
<li><strong>Media</strong> (copper cable, fiber optics, RF waves, etc.)</li>
<li><strong>Services</strong> (firewalling, web sites, file transfers, etc.)</li>
</ul>
<p>Even the smaller one has them all.</p>
</section>
<section>
<h2>(End) Devices</h2>
<p>An <strong>(end) host device</strong> is a device that can be the source or the destination of a network communication.</p>
<p>They can be thought as the <strong>interface between humans and networks</strong>.</p>
<p>End devices can be distinguished and reached on a network by their <strong>addresses</strong>.</p>
<p>Examples?</p>
</section>
<section>
<section>
<h2>Intermediary Devices</h2>
<p><strong>Intermediary devices</strong> carry the task to <strong>ensure data flows</strong> through the network to reach end devices, connecting them.</p>
<p>Their functions include <strong>signal regeneration</strong>, error handling, keeping track of pathways among and between networks, prioritizing and securing traffic.</p>
<p><strong>Network Access</strong> (switches, AP, hubs), <strong>Internetworking</strong> (routers), <strong>Security</strong> (firewalls) devices are all intermediary devices.</p>
</section>
<section>
<h2>Intermediary Device: Switch</h2>
<img src="https://i.imgur.com/c7xJlTj.png">
</section>
<section>
<h2>Intermediary Device: Hub</h2>
<img src="https://i.imgur.com/JFMIool.jpg">
</section>
<section>
<h2>Intermediary Device: Access Point</h2>
<img src="https://i.imgur.com/qcvNPjT.jpg">
</section>
<section>
<h2>Intermediary Device: Router</h2>
<img src="https://i.imgur.com/vFFjkzh.jpg">
</section>
<section>
<h2>Intermediary Device: Firewall</h2>
<img src="https://i.imgur.com/87rmuB3.jpg">
</section>
</section>
<section>
<h2>Network Media</h2>
<p>The <strong>medium</strong> is the physical object that carries the signal from one point of the network to the other.</p>
<p>There are mostly 3 types of media:</p>
<ul>
<li>Metallic wires/cables</li>
<li>Glass/Plastic fibers</li>
<li>Wireless</li>
</ul>
<p>Signal must be <em>encoded</em> in a way that is appropriate to each media.</p>
</section>
<section>
<h2>How do you choose a media?</h2>
<p>Different media have <strong>different features, PROs and CONs</strong>. The most common criteria for choosing a media are:</p>
<ul>
<li><strong>Distance</strong> that can be covered by the media</li>
<li><strong>Environment</strong> in which the media will be operating.</li>
<li><strong>Amount</strong> of data and requires <strong>speed</strong> of tranmission.</li>
<li><strong>Costs</strong>, of media itself and its installation.</li>
</ul>
</section>
<section>
<h2>Port vs. Interface</h2>
<ul>
<li><strong>Port</strong> - It's a physical connector that allows a cable to be plugged in and the communication circuit to be closed.</li>
<li><strong>Interface</strong> - It's a specialized port that is used to connect to an individual network.</li>
<ul>
<li>It's also the name for the software (<em>logical</em>) equivalent of a port. Programs and OSes <em>see</em> physical port(s) through an interface.</li>
</ul>
<li><strong>NIC (<em>Network Interface Card</em>)</strong> - An extension available to certain devices (e.g. a PC) to provide additional networking capabilities.</li>
</ul>
<p>Very often there is a <strong>1:1 relation</strong> between a port and an interface, so they are (sometimes wrong) used as synonyms.</p>
</section>
<section>
<section>
<h2>Topology Diagrams</h2>
<p>A <strong>Network Topology</strong> is a visual representation of a network or one specific aspect of it.</p>
<p>It easily allows to <strong>document</strong> network connections.</p>
<p>Mainly 2 types of topology diagrams:</p>
<ul>
<li><strong>Physical Topology</strong>: its purpose is to highlight the <strong>location</strong> of each devices, configuration of ports and cables path.</li>
<li><strong>Logical Topology</strong>: you can visualize <strong>devices by their functions</strong>, addressing schemes, ports and other network parameters.</li>
</ul>
</section>
<section>
<h2>Physical Topology</h2>
<img src="https://i.imgur.com/NUZfFQ8.jpg">
</section>
<section>
<h2>Logical Topology</h2>
<img src="https://i.imgur.com/eV3RAAm.jpg">
</section>
</section>
<section>
<h2>Networks by Geographic Scale</h2>
<p>A network can be <strong>characterized by its physical capacities</strong> (size of the area, number of users), by <strong>administrative entity</strong>, and also by the <strong>services</strong> it provides. The most common types based on these parameters are:</p>
<ul>
<li><strong>LAN</strong>: Local Area Network</li>
<li><strong>WAN</strong>: Wide Area Network</li>
<li><strong>MAN</strong>: Metropolitan Area Network</li>
<li><strong>WLAN</strong>: Wireless Local Area Network</li>
<li><strong>SAN</strong>: Storage Area Network</li>
</ul>
</section>
<section>
<h2>LAN: Local Area Networks</h2>
<p>It's a network that covers a relatively small, <strong>limited geographical area</strong>. LANs share these characteristics:</p>
<ul>
<li>Devices participating in a LAN are located in a <strong>self-containing area</strong>, like a home, school, building.</li>
<li>They are <strong>administered by a single entity</strong> that controls access, features and policies in general.</li>
<li>Almost every time they provide the <strong>fastest bandwidth</strong> to end and intermediate devices, when compared to other type of networks.</li>
</ul>
</section>
<section>
<h2>WAN: Wide Area Networks</h2>
<p>The <strong>textbook definition</strong> is: a computer network spanning cities, regions, countries, or even the world.</p>
<p>WAN are more generally referred to as a <strong>set of technologies for trasmitting datas over long distances, between more localized types of networks</strong>. Typically LANs.</p>
<p>Either they're <strong>slower than LANs</strong>, or much <strong>more expensive</strong> for the same bandwidth.</p>
<p>Generally managed by <strong>multiple entities</strong>, usually <strong>service providers</strong>.</p>
</section>
<section>
<h2>Networks by scope:</h2>
<h2>Intranet and Extranet</h2>
<p><strong>Intranet</strong> is defined as the ensemble of private connections of LANs and WANs belonging and only accessible to a <strong>single entity</strong>.</p>
<p><strong>Extranet</strong>s are also under a single administration, but supports connection and (limited) access from <strong>specific external networks</strong>.</p>
</section>
<section>
<section>
<h2>Networks by scope</h2>
<h2>The Internet</h2>
<p>The Internet is a network formed by a staggering amount of <strong>inter</strong>connected <strong>net</strong>works.</p>
<p>How do you make a network made of billions of different devices, users and medium, work flawlessly? <strong>Standards</strong>.</p>
<p>No single entity, government, organization owns The Internet. But it all works thanks to <strong>consistent, globally recognized and available technologies and protocols</strong>.</p>
<p>There are many organizazions that were purposefully created to <strong>maintain and produce</strong> these standards.</p>
</section>
<section>
<h2>Networks by scope</h2>
<h2>The Internet</h2>
<p>~Every LANs + ~ Every WAN = Internet.</p>
<img src="https://i.imgur.com/hn4L5qy.jpg">
</section>
</section>
<section>
<h2>Connecting to the Internet: Users</h2>
<ul>
<li><strong>ADSL/VDSL</strong>: Internet over telephone lines. Download speeds are higher than upload speeds.</li>
<li><strong>Cable</strong>: Internet over TV cable (not italian stuff, really).</li>
<li><strong>Fiber Optics</strong>: Internet at the speed of light (sort of).</li>
<li><strong>Cellular</strong>: Internet over cell towers.</li>
<li><strong>Satellite</strong>: Internet over parabolic dishes.</li>
<li><strong>Dial-up</strong>: Internet over 20 years ago.</li>
</ul>
</section>
<section>
<h2>Connecting to the Internet: Businesses</h2>
<ul>
<li><strong>Dedicated Leased Lines</strong>: This is my circuit. There are many circuits like this, but this one is mine.</li>
<li><strong>Metro Ethernet</strong>: Ethernet over Copper or Fiber, from 10 Mb/s to 10 Gb/s.</li>
<li><strong>SDSL</strong>: a DSL configured for symmetrical upload and download speeds.</li>
<li><strong>Satellite</strong>: like the one for the regular user, but you can upload stuff in space.</li>
</ul>
</section>
<section>
<h2>Converged Networks</h2>
<p>Telephone, television, radio, data, are all examples of communications that <strong>used to require a dedicated, separate network</strong> for each one of them.</p>
<p>Digital age and the ubiquity of the Internet is changing all that, making it possible to <strong>deliver everything over a single network</strong>.</p>
<p>Cisco calls this the <em>Converging Network</em>.</p>
</section>
<section>
<h2>Cisco's 4 basic network features</h2>
<ul>
<li>Fault Tolerance</li>
<li>Scalability</li>
<li>Quality of Service (QoS)</li>
<li>Security</li>
</ul>
</section>
<section>
<h2>#1: Fault Tolerance</h2>
<p><strong>Fault Tolerance</strong> is the ability to <strong>limit the impact of a failure</strong> in a network and to quickly recover from it.</p>
<p>Networks achieve this by having <strong>multiple paths</strong> on which communication can occur.</p>
<p>Only <strong><em>packet-switched</em> networks</strong> can take advantage of multiple paths, as opposed to old <strong><em>circuit-switched</em></strong> networks.</p>
</section>
<!--
<section>
<section>
<h2>Circuit-Switching and Faults</h2>
<img src="http://upload.wikimedia.org/wikipedia/commons/thumb/8/8e/Photograph_of_Women_Working_at_a_Bell_System_Telephone_Switchboard_%283660047829%29.jpg/640px-Photograph_of_Women_Working_at_a_Bell_System_Telephone_Switchboard_%283660047829%29.jpg" width="465" height="381">
<p>First there's the <strong>setup process</strong>, that involes creating a <strong>temporary path/circuit</strong> between source and destination.</p>
</section>
<section>
<h2>Circuit-Switching and Faults</h2>
<img src="http://www.louiewong.com/wp-content/uploads/2010/09/Circuit_Switching.jpg" style="width: 50%; height: 50%;">
<p><strong>Any failure</strong> along the circuit means the communication is dropped and a <strong>new setup process</strong> has to begin.</p>
<p><strong>Existing communications are at the expense of new ones</strong>: even if a circuit is unused, you get the busy signals.</p>
<p><strong>No-go</strong> for the Internet.</p>
</section>
</section>
<section>
<section>
<h2>Packet-Switching and Faults</h2>
<img src="http://computernetworkingsimplified.com/wp-content/uploads/2013/11/DatagramSwitching.jpg" width="672" height="305">
<p>Key concept is that <strong>a single message can be splitted</strong> into pieces, each one containing <strong>information identifying source and destination</strong>.</p>
</section>
<section>
<h2>Packet-Switching and Faults</h2>
<p>Message can be sent along a <strong>multitude of paths</strong> and then <strong>reassembled</strong> at its destination.</p>
<p>At each intermediary device location, <strong>a switching/routing decision</strong> is made about the path of each packet.</p>
<p>Fault Tolerance lies in the ability to <strong>dinamically choose alternative/best path</strong> with ease.</p>
<p>Failures are dealt with by <strong>retransmission</strong> only of the packets involved.</p>
</section>
<section>
<h2>Circuit vs. Packet Switching</h2>
<img src="http://computing.dcu.ie/~humphrys/Notes/Networks/tanenbaum/2-40.jpg">
</section>
</section>
-->
<section>
<h2>#2: Scalability</h2>
<p>Scalability is the <strong>ability of a network to grow</strong> in users, devices, traffic, etc <strong>without affecting performance</strong> levels.</p>
<p>The Internet could grow this much precisely because <strong>its architecture is scalable</strong> technically and politically.</p>
<!-- <p>The Internet is structured in <strong>Network Tiers (1+2+3)</strong>, exchanging <strong>peering or transit traffic</strong> between them.</p> -->
<p>Scalability without <strong>standards</strong> would be just too painful to achieve.</p>
</section>
<!--
<section>
<section>
<h2>Internet Tiers, Peering and Transit</h2>
<img src="https://i.imgur.com/hVyL0BP.png" style="background: white; width: 60%; height: 60%;">
<p>The Internet is based on the principle of <strong>general reachability</strong>: every Internet user should be able to reach any other Internet user. But how is that possible?</p>
</section>
<section>
<h2>Internet Tiers, Peering and Transit</h2>
<ul>
<li><strong><u>Tier 1</u></strong>: they're the <strong>backbone</strong> of the Internet, providing international and trans-oceanic connectivity. Tier 1 ISPs treat each other as <strong>peers</strong>.</li>
<li><strong><u>Tier 2</u></strong>: smaller ISPs but still operating at a scale, they can <strong>buy transit</strong> to the rest of the Internet and <strong>peer</strong> with other Tier 2 providers, and <strong>sell transit</strong> to Tier 3 ISPs.</li>
<li><strong><u>Tier 3</u></strong>: these are the more local ISPs that directly <strong>provide Internet access to the final users</strong>.They mostly buy transit from Tier 2 providers.</li>
</ul>
</section>
</section>
-->
<section>
<section>
<h2>#3: Quality of Service (QoS)</h2>
<img src="https://i.imgur.com/skKIsGd.gif">
<small>What's this? A cat farting or a team of surgeons liveconferencing from the hospital? We'll find out soon (?)...</small>
<p>When you want <strong>predictable, measurable and guaranteed</strong> services on a network, you need to implement <strong>Quality of Service</strong> solutions.</p>
</section>
<section>
<h2>#3: Quality of Service (QoS)</h2>
<p>Packet-switched network means there's <strong>no guarantee packets will arrive on time. Or at all</strong>.</p>
<p>When the amount and size of the packets exceed <strong>network bandwidth</strong>, packets are <strong>queued in memory</strong>. Until it's full...</p>
<p>Achieving QoS is all about <strong>managing delay and packet loss</strong> when a <em>congestion</em> arises.</p>
<p>We can do that through <strong>classification and priority rules</strong> based on our own criteria.</p>
</section>
</section>
<section>
<h2>#4: Security</h2>
<p>Not just physical security but also <strong>information security</strong>.</p>
<p>Security is a matter of 3 basic requirements:</p>
<ul>
<li><strong>Confidentiality</strong>: data, processes, resources can only be <strong>accessed by authorized</strong> users. Authentication and Encryption to the rescue.</li>
<li><strong>Integrity</strong>: It's about ensuring the <strong>data haven't been altered during transmission</strong>, either by accident or maliciously. It could involve <em>checksums</em> and <em>signatures</em>.</li>
<li><strong>Availability</strong>: data and resources must be accessible to the legitimate users when they need them. <strong>Denial of Service (DoS)</strong> attacks can damage you without even breaking into your network.</li>
</ul>
</section>
<section>
<h2>Network Trends for Businesses</h2>
<ul>
<li><strong>BYOD (Bring Your Own Device)</strong> means that you can use any device, with any ownership, in any IT organization.</li>
<li><strong>Cloud Computing</strong> refers to the <strong>offloading of computing</strong> resources and data storage, then <strong>delivered as a service</strong> over a network.</li>
<ul>
<li>Benefits: usable anywhere, rapid deployment, reduced costs, refocused resources, new business models.</li>
<li>4 primary types of clouds: <strong>Public, Private, Custom, Hybrid</strong></li>
</ul>
<li><strong>Virtualization</strong> is running a virtual version of something on a computer, <strong>like an entire hardware platform, an operating system</strong>, a single device, storage or networks.</li>
</ul>
</section>
<section>
<h2>Network Trends for Home Users</h2>
<ul>
<li><strong>Smart home technology</strong> integrates computing capabilities into every-day machinery, interconnecting and automating them.</li>
<li><strong>Powerline Networking</strong> uses electrical wiring to transfer data on a network; works very similarly to DSL.</li>
<li><strong>Wireless Internet Service Provider</strong>s sell Internet access through wireless technology. The connection to the provider's backbone requires the installation of an <strong>antenna</strong>.</li>
</ul>
</section>
<section>
<section>
<h2>Network Security: Threats</h2>
<p>These are among the most common dangers a network has to be guarded from:</p>
<ul>
<li>Viruses, worms, and Trojan horses</li>
<li>Spyware and adware</li>
<li>0-day vulnerabilities</li>
<li>Hackers (but they mean: <em>crackers</em>)</li>
<li>Denial of Service</li>
<li>Data theft</li>
<li>Identity theft</li>
</ul>
<p>But keep in mind that, most of the time, your enemy is <strong>already inside</strong>.</p>
</section>
<section>
<h2>Network Security: Solutions</h2>
<p><strong>Security is a process, not a solution</strong>. Solutions works best when they are carefully combined and layered.</p>
<ul>
<li>Basic: <strong>Antivirus and antispyware</strong>.</li>
<li>Basic: <strong>Firewall filtering</strong> on end devices and home routers.</li>
<li>Advanced: <strong>Dedicated Firewalls</strong> and <strong>Access Control Lists (ACL)</strong>.</li>
<li>Advanced: <strong>Intrusion Prevention Systems (IPS)</strong>.</li>
<li>Advanced: <strong>Virtual Private Networks (VPN)</strong>.</li>
</ul>
</section>
</section>
<section>
<h1>End of Lesson</h1>
</section>
</div>
</div>
<script src="lib/js/head.min.js"></script>
<script src="js/reveal.js"></script>
<script>
// More info https://github.com/hakimel/reveal.js#configuration
Reveal.initialize({
controls: true,
progress: true,
history: true,
center: true,
transition: 'slide', // none/fade/slide/convex/concave/zoom
// More info https://github.com/hakimel/reveal.js#dependencies
dependencies: [
{ src: 'lib/js/classList.js', condition: function() { return !document.body.classList; } },
{ src: 'plugin/markdown/marked.js', condition: function() { return !!document.querySelector( '[data-markdown]' ); } },
{ src: 'plugin/markdown/markdown.js', condition: function() { return !!document.querySelector( '[data-markdown]' ); } },
{ src: 'plugin/highlight/highlight.js', async: true, callback: function() { hljs.initHighlightingOnLoad(); } },
{ src: 'plugin/zoom-js/zoom.js', async: true },
{ src: 'plugin/notes/notes.js', async: true }
]
});
</script>
</body>
</html>