Designing Remote Connectivity Part 01 — Transcript

Full transcript

1. 0:04hi
2. 0:04hello there welcome to designing remote
3. 0:07connectivity
4. 0:08this video discusses the one function
5. 0:11that provides access to remote sites and
6. 0:14the outside world
7. 0:16it details one technologies and one
8. 0:19design considerations
9. 0:21the video explores how these
10. 0:23technologies were used
11. 0:24including for remote access with virtual
12. 0:27private networks or vpn for backup
13. 0:30and how the internet is used as a backup
14. 0:33one
15. 0:34this video describes the enterprise one
16. 0:37in the metropolitan area or man
17. 0:38architecture
18. 0:40and the enterprise branch and teleworker
19. 0:42architectures
20. 0:44the selection of one hardware and
21. 0:46software components
22. 0:48is also discussed
23. 0:53now for the topic outline of this video
24. 0:54lecture designing remote connectivity
25. 0:58this video will cover identifying one
26. 1:00technology considerations
27. 1:03designing the enterprise one and
28. 1:06designing
29. 1:06the enterprise branch at the end of this
30. 1:10video lecture
31. 1:10we are going to summarize designing
32. 1:13remote connectivity
33. 1:14let's get started
34. 1:17identifying one technology
35. 1:19considerations
36. 1:23enterprise edge 1 technologies so this
37. 1:26section
38. 1:26introduces the concept of the wide area
39. 1:29networks are one
40. 1:31beginning with the definition of one in
41. 1:34the types of
42. 1:34one interconnections various one
43. 1:37technologies are described
44. 1:39the section concludes with the
45. 1:41discussion of one pricing
46. 1:43and contract considerations
47. 1:48designing a one is a challenging task
48. 1:51the first design step
49. 1:52is to understand the ones networking
50. 1:54requirements
51. 1:56which are driven by two primary goals
52. 2:00first you've got the service level
53. 2:01agreement or the slas
54. 2:04networks carry application information
55. 2:06between computers
56. 2:08if the applications are not applicable
57. 2:10to network users
58. 2:12the network fails to achieve its design
59. 2:14objectives
60. 2:16organization need to define the level of
61. 2:19service such as bandwidth
62. 2:21allowed latency packet loss and so forth
63. 2:24that is acceptable for the applications
64. 2:27running across the one
65. 2:29the second one is the cost of investment
66. 2:32and usage
67. 2:33one designs are always subject to budget
68. 2:37limitations
69. 2:38selecting the right type of one
70. 2:40technology is critical
71. 2:42to providing a reliable services for end
72. 2:44user applications
73. 2:46in a cost effective and efficient manner
74. 2:50now flowing from these goals are the
75. 2:52following objectives
76. 2:54for an effective one design so a
77. 2:57well-designed
78. 2:58one must reflect the goals
79. 3:01characteristics
80. 3:02and policies of an organization
81. 3:05the selected one technology should be
82. 3:07sufficient for the current
83. 3:09and to some extent use your application
84. 3:12requirements
85. 3:13the associated costs of investment and
86. 3:17usage
87. 3:18should stay within the budget limits
88. 3:24one interconnections now this figure
89. 3:27here
90. 3:27illustrates a three way that one
91. 3:31technologies connect
92. 3:32the enterprise edge modules
93. 3:35with the outside world represented by
94. 3:37the service provider network
95. 3:40so typically the intent is to provide
96. 3:43the following connections
97. 3:44so connectivity between the enterprise
98. 3:47edge
99. 3:47modules in the internet service provider
100. 3:50edge or the isp edge
101. 3:51modules so connectivity between the
102. 3:55enterprise sites across the isp network
103. 3:58connectivity between the enterprises
104. 4:00across the service provider or public
105. 4:02switch telephone network or pstn
106. 4:04carrier network so
107. 4:07one connections can be a point to point
108. 4:10between two locations
109. 4:12or connections to a multi-point
110. 4:15so one service offering such as the old
111. 4:18frame relay
112. 4:19or the multi-protocol label switching or
113. 4:21mpls network
114. 4:23one of the main issues in one
115. 4:26connections is selecting the appropriate
116. 4:28physical one technology
117. 4:32now what are the one transfer
118. 4:33technologies
119. 4:35the table here compares various one
120. 4:38technologies
121. 4:39based on the main factors that influence
122. 4:41technology selection
123. 4:44so this table provides typical baseline
124. 4:46characteristics
125. 4:48to help you compare the performance and
126. 4:50features
127. 4:51offered by different technologies so
128. 4:54often the offerings of the service
129. 4:57provider
130. 4:58limit your technology decisions
131. 5:02you can go ahead and search for these
132. 5:03technologies
133. 5:05on the internet
134. 5:09example of a dsl implementation an adsl
135. 5:13circuit connects an adsl modem
136. 5:16on each end of a twisted pair telephone
137. 5:19line
138. 5:20this creates three information channels
139. 5:23so you've got the medium speed
140. 5:25downstream channel
141. 5:27the low speed upstream channel and of
142. 5:29course the basic telephone service
143. 5:31channel
144. 5:32so filters or splitters split off the
145. 5:35basic telephone service channel
146. 5:37from the digital modem guaranteeing an
147. 5:40uninterrupted
148. 5:41basic telephone service even if adsl
149. 5:43fails
150. 5:47now i have here an example of data over
151. 5:51our data in voice over cable
152. 5:54so this figure illustrates
153. 5:57some of the components used to transmit
154. 5:59data and voice
155. 6:01on a cable network so the universal
156. 6:04broadband router
157. 6:05or the ubr also referred to as the cable
158. 6:08modem termination system or the cmts
159. 6:12provides high-speed data connectivity
160. 6:15and is deployed at the cable companies
161. 6:17heading
162. 6:19so the ubr forwards data streams to
163. 6:21connect
164. 6:22with either the psdn or
165. 6:25the internet so the cable modem also
166. 6:29referred to as a cable access router
167. 6:32at the customer location offers support
168. 6:35for transmission of voice modem and fax
169. 6:39calls over the tcp ip cable network
170. 6:42example of the three users of wireless
171. 6:46now common examples of wireless
172. 6:48equipment include cellular phones
173. 6:51global positioning systems cordless
174. 6:53computer peripherals
175. 6:55satellite televisions and wireless lands
176. 6:57or w lands
177. 6:59so as shown in this figure here wireless
178. 7:01implementations includes
179. 7:03bridge wireless cellular wireless
180. 7:07and wireless lans now for the bridge
181. 7:10wireless this is designed to connect two
182. 7:13or more networks
183. 7:14typically located in different buildings
184. 7:17at
185. 7:17high data rates for data intensive line
186. 7:20of sight applications
187. 7:22a series of wireless bridges or routers
188. 7:26connect discreet distance sites into a
189. 7:29single land
190. 7:30interconnecting hard to wire sites
191. 7:32non-contiguous floors
192. 7:35satellite offices school or corporate
193. 7:37campus settings
194. 7:39temporary networks and warehouses
195. 7:43next would be the mobile wireless so
196. 7:45this includes
197. 7:47cellular voice and data applications
198. 7:50wireless technology usage increased with
199. 7:52introduction of digital services on
200. 7:54wireless
201. 7:55second and third generation mobile
202. 7:57phones offer better connectivity
203. 8:00and higher speeds so mobile wireless
204. 8:03technologies
205. 8:04includes the following you've got the
206. 8:06gps
207. 8:08okay the global system for mobile um
208. 8:12or gsm the general packet radio service
209. 8:15or gprs
210. 8:16the universal mobile telephone service
211. 8:19or umts
212. 8:21the code division multiple access or the
213. 8:24cdma and other technologies
214. 8:27next would be the wireless lan so
215. 8:30developed because
216. 8:31of demand for land connections over the
217. 8:34air
218. 8:34and often used for intra building
219. 8:37communications
220. 8:39so wlan technology can replace a
221. 8:41traditional wired network
222. 8:43or extend its reach and capabilities
223. 8:47wlans cover a growing range of
224. 8:49applications such as guest access and
225. 8:51voice
226. 8:52and support services such as advanced
227. 8:55security and location of wireless
228. 8:57devices
229. 9:01synchronous optical network and
230. 9:03synchronous digital hierarchy
231. 9:06so sonet or the synchronous optical
232. 9:09network
233. 9:10okay and you've got the sdh or the
234. 9:13synchronous digital hierarchy
235. 9:15this is a circuit-based bandwidth
236. 9:17efficient technology
237. 9:19so sonet sdh establishes
238. 9:22a high speed circuit using tdm frames
239. 9:25hindering topologies
240. 9:27over an optical infrastructure as
241. 9:29illustrated here in the diagram
242. 9:31so it results in a guaranteed bandwidth
243. 9:33regardless of the actual usage
244. 9:36so common bit rates are 155 mbps and 622
245. 9:40mbps
246. 9:42with a current maximum of 10 gbps
247. 9:45per gigabit per second
248. 9:50next would be the dense wavelength
249. 9:52division multiplexing
250. 9:53or dwdm so dense
251. 9:56wavelength division multiplexing is
252. 9:59illustrated
253. 10:00on this figure which increases the
254. 10:02bandwidth on optical medium
255. 10:05so dwdm increases the available
256. 10:07bandwidth on a single strand of fiber
257. 10:10using a multi-channel signaling
258. 10:14dwdm is a crucial component of optical
259. 10:17networks
260. 10:19it maximizes the use of installed fiber
261. 10:22cable and allows
262. 10:23new services to be provisioned
263. 10:25efficiently over the existing
264. 10:27infrastructure
265. 10:28so flexible add and drop modules
266. 10:32allow individual channels to be dropped
267. 10:34and inserted along or out
268. 10:37an open architecture system allows the
269. 10:39interconnection
270. 10:40of a variety of devices including sony
271. 10:43terminals
272. 10:44atm switches and ip routers
273. 10:48dwgm is also used inside a zone at sdh
274. 10:51ring
275. 10:54next would be the dark fiber so dark
276. 10:57fiber refers to fiber optic cables
277. 11:01list from the service provider and
278. 11:04connected to a company's
279. 11:05own infrastructure so dark fiber is
280. 11:08illustrated on this figure here
281. 11:11so the framing of a dark fiber is
282. 11:14provided by a company's devices and does
283. 11:16not have
284. 11:17to be a sonnet or sdh
285. 11:20so as a result the dark fiber connection
286. 11:23eliminates the need
287. 11:25for sauna sds multiplexers which
288. 11:28are required in sonnet sdh rings
289. 11:32each edge device connects directly over
290. 11:35the side to side
291. 11:36dark fiber using a layer to
292. 11:38encapsulation such as
293. 11:40gigabit ethernet
294. 11:43now when such connectivity is used to
295. 11:45transmit data over significantly long
296. 11:47distances
297. 11:49regenerators or dwdm concentrators
298. 11:52are inserted into the link to maintain
299. 11:55signal integrity and provide
300. 11:57appropriate jitter control
301. 12:02one transport technology pricing
302. 12:04considerations
303. 12:06so pricing used to include an access
304. 12:09circuit
305. 12:10and a distance sensitive break
306. 12:13so access circuit provisioning generally
307. 12:16takes 60 days
308. 12:17or more lead time now for the
309. 12:21technology like the old frame relay and
310. 12:23atm pricing includes
311. 12:25an access circuit charge well this would
312. 12:29definitely depend if the service is
313. 12:32provided in your area
314. 12:34so sometimes you've got a per pvc and
315. 12:37possibly per bandwidth
316. 12:39charges mpls vpn pricing is generally
317. 12:43comparable
318. 12:44with old frame relays and atm so
319. 12:47take note that the pricing time frame
320. 12:50and contract details provided here are
321. 12:53examples
322. 12:54from the u.s market okay
323. 12:58now organization in other countries
324. 13:00might have different experiences however
325. 13:03the items in this section should be
326. 13:05considered when
327. 13:06implementing a wide area network service
328. 13:09and pricing options between carriers
329. 13:13should be compared and negotiated
330. 13:15depending on competition in the area
331. 13:20methodology used in the enterprise edge
332. 13:22design
333. 13:24so this section describes the one design
334. 13:27methodology and the application and
335. 13:29technical requirements
336. 13:30aspects of the one design the different
337. 13:33possibilities for one ownership are
338. 13:35discussed
339. 13:36so one bandwidth optimization techniques
340. 13:38are described
341. 13:40the methodology espoused
342. 13:44here follows the guidelines for the
343. 13:46prepare
344. 13:47plan design implement operate optimize
345. 13:50or the ppgio methodology
346. 13:53introduced in the previous video
347. 13:54applying methodology to a network design
348. 13:58now the network designer should follow
349. 14:00these steps when planning and designing
350. 14:02the enterprise edge
351. 14:04based on the ppdio methodology
352. 14:07so step one would be analyzing the
353. 14:11customer requirements
354. 14:13the initial setup or the initial step in
355. 14:16the design methodology
356. 14:18is to analyze the requirements of the
357. 14:20network
358. 14:21and each users including the type of
359. 14:24applications
360. 14:26the traffic volume and the traffic
361. 14:29patterns
362. 14:31second would be characterizing the
363. 14:33existing network and sites
364. 14:35the second step is to analyze the
365. 14:37existing networking infrastructure and
366. 14:39sites
367. 14:40including the technology used and the
368. 14:43location
369. 14:44of hosts servers terminals
370. 14:47and other endnotes step 3
371. 14:51is designing the network topology and
372. 14:53solutions
373. 14:54the final step in the design methodology
374. 14:57is to develop the
375. 14:58overall network topology and its
376. 15:01appropriate services
377. 15:02based on the availability of the
378. 15:04technology
379. 15:06and taking part into
380. 15:09the projected traffic patterns
381. 15:11technology performance constraints
382. 15:14and network reliability
383. 15:19identifying application requirements so
384. 15:22application requirements
385. 15:23of a1 design so just as
386. 15:26application requirements drives the
387. 15:28enterprise campus design as illustrated
388. 15:31in the previous
389. 15:31video designing basic campus and data
390. 15:34center networks
391. 15:36they also affect the enterprise edge one
392. 15:39design
393. 15:40so application availability is a key
394. 15:43user requirement
395. 15:45the chief components of application
396. 15:48availability
397. 15:49are response time so throughput
398. 15:54packet loss okay and reliability
399. 15:57now this table here analyzes these
400. 15:59components
401. 16:01which are discussed in the following
402. 16:03sections
403. 16:04so first let's discuss the response time
404. 16:08response time is the time between a user
405. 16:11requests
406. 16:12such as the entry of a command or
407. 16:15keystroke
408. 16:16and the whole system's command execution
409. 16:19or response delivery
410. 16:21in data transmission throughput is the
411. 16:24amount of data moved successfully
412. 16:27from one place to another in a given
413. 16:29time period
414. 16:31in telecommunication transmission packet
415. 16:34loss is expressed
416. 16:36as bit error rate or ber
417. 16:40which is the percentage of bits that
418. 16:42have errors
419. 16:44relative to the total number of bits
420. 16:46received in transmission
421. 16:49reliability although reliability is
422. 16:52always important
423. 16:53some applications have requirements
424. 16:57that exceed typical needs
425. 17:02determining the maximum offered traffic
426. 17:04so technical requirements
427. 17:06maximum offer traffic so the goal of
428. 17:09everyone design
429. 17:10should be to optimize link performance
430. 17:13in terms of
431. 17:15offered traffic link utilization
432. 17:18and response time so to optimize link
433. 17:21performance
434. 17:22the designer must balance between end
435. 17:24user and network manager requirements
436. 17:27which are usually diametrically opposed
437. 17:30so and users usually require minimum
438. 17:33application response times
439. 17:35over a one link whereas the network
440. 17:38manager's goal is to maximize the link
441. 17:40utilization
442. 17:42one resources have a finite capacity
443. 17:46so response time problems typically
444. 17:48affects
445. 17:49only users for example
446. 17:53it probably does not matter to the
447. 17:55network manager if query results are
448. 17:57returned 120 milliseconds sooner rather
449. 18:00than later
450. 18:02so response time is a thermometer of
451. 18:05usability for users so users
452. 18:09perceive data processing experience in
453. 18:12terms of how quickly they can get
454. 18:14their screen to update so they view
455. 18:18data processing in terms of response
456. 18:21time
457. 18:22and do not actually care about link
458. 18:23utilization
459. 18:25so the graph here illustrates the
460. 18:27response time and link utilization
461. 18:29relative to
462. 18:30offered traffic so the response time
463. 18:34increases
464. 18:35when the offered traffic until it
465. 18:37reaches an acceptable
466. 18:39or unacceptable point for the end user
467. 18:43so similarly the link utilization
468. 18:45increases
469. 18:46with the offered traffic to the point
470. 18:48that the link becomes saturated
471. 18:51so the designer's goal is to determine
472. 18:54the maximum offered traffic
473. 18:56that is acceptable to both the end user
474. 18:59and the network manager
475. 19:04technical requirements bandwidth
476. 19:07so in a qualitative sense the required
477. 19:10bandwidth is proportional
478. 19:12to the data's complexity for a given
479. 19:15level of system performance
480. 19:17so for example downloading a photograph
481. 19:21in one second takes
482. 19:22more bandwidth than downloading a page
483. 19:25of
484. 19:25text in one second so large
485. 19:28sound files computer programs and
486. 19:30animated videos
487. 19:32require even more bandwidth for
488. 19:34acceptable system performance
489. 19:37so one of the main issues involved in
490. 19:39one connections
491. 19:42is the selection of appropriate
492. 19:43technologies
493. 19:45that provide sufficient bandwidth now
494. 19:48this table here
495. 19:49illustrates the ranges of bandwidth
496. 19:51commonly supported
497. 19:52by the given technologies
498. 19:55so bandwidth is inexpensive in the land
499. 19:59where connectivity is typically limited
500. 20:01only by hardware implementation
501. 20:03and ongoing maintenance costs in
502. 20:06one bandwidth has typically been the
503. 20:09overriding cost
504. 20:11the delay sensitive traffic such as a
505. 20:13voice
506. 20:14has remained separate from data however
507. 20:18new applications and economics of
508. 20:21supporting them
509. 20:22are forcing these conventions to change
510. 20:26and basically the ideal choice here is
511. 20:29the use of fiber optic
512. 20:33evaluating the cost effectiveness of one
513. 20:36ownership
514. 20:38so in the one environment the following
515. 20:40usually represented
516. 20:42fixed costs equipment purchase such as
517. 20:45modems
518. 20:47channel device or service unit data
519. 20:50service
520. 20:50units and router interfaces
521. 20:54circuit and service provisioning
522. 20:58network management tools and platforms
523. 21:01recurring costs
524. 21:02includes the monthly circuit fees from
525. 21:04the service providers
526. 21:06and the one support and maintenance
527. 21:08including any network management center
528. 21:11personnel
529. 21:12so from the ownership perspective one
530. 21:15links can be thought
531. 21:17of the following three categories here
532. 21:19private
533. 21:20list and shared now for private
534. 21:25a private one uses private transmission
535. 21:28systems to connect distant lands
536. 21:30the owner of the private one must buy
537. 21:33configure and maintain the physical
538. 21:36layer connectivity such as copper
539. 21:38fiber wireless and coaxial if some of
540. 21:41the organizations are still using
541. 21:42auxilia and the terminal equipment
542. 21:45required
543. 21:46to connect locations next would be
544. 21:50list a list one uses dedicated bandwidth
545. 21:54from a carrier company
546. 21:56with either private or leased terminal
547. 22:00equipment
548. 22:01the provider provisions the circuit and
549. 22:04provides
550. 22:05the maintenance last would be shared
551. 22:09a shared one shares the physical
552. 22:11resources with many users
553. 22:14carriers offer a variety of circuit or
554. 22:16packet switching transport networks such
555. 22:18as mpls and other technologies
556. 22:25optimizing bandwidth in a one
557. 22:29it is expensive to transmit data over
558. 22:32one
559. 22:33therefore one of many different
560. 22:34techniques such as
561. 22:36a data compression bandwidth combination
562. 22:41tuning the window size congestion
563. 22:44management doing and scheduling
564. 22:46congestion avoidance and traffic shaping
565. 22:48and policing can be used to optimize
566. 22:50bandwidth usage
567. 22:52and improve overall performance
568. 22:56so the following sections describes this
569. 22:58technique so let's start with
570. 23:00data compression so compression is a
571. 23:03reduction of data size
572. 23:04to save transmission compression enables
573. 23:08more efficient use
574. 23:10of the available one bandwidth which is
575. 23:13often limited and is generally a
576. 23:15bottleneck
577. 23:16compression allows higher throughput
578. 23:19because
579. 23:20it squeezes packet size and therefore
580. 23:24increases the amount of data that can be
581. 23:26sent
582. 23:26through a transmission resource in a
583. 23:28given time period
584. 23:30okay so the next one would be bandwidth
585. 23:34combination
586. 23:36so ppp is commonly used to establish a
587. 23:39direct connection between two devices
588. 23:42pvp is point to point protocol this is a
589. 23:45layer 2 protocol
590. 23:48for connection over synchronous and
591. 23:50asynchronous circuits
592. 23:52so for example ppp is used when
593. 23:54connecting computers
594. 23:55using serial cables phone lines
595. 23:58trunk lines cellular telephones
596. 24:01specialized
597. 24:02radio links or fiber optic links
598. 24:06an encapsulated form of ppp which is the
599. 24:09pppoe
600. 24:10or pppoa is commonly used in a similar
601. 24:14role
602. 24:15with dsl internet service
603. 24:18so the next one is windows size
604. 24:21windows size is the maximum number of
605. 24:23frames or amount of data
606. 24:25the sender can transmit before it must
607. 24:27wait for an acknowledgement
608. 24:30the current windows size is defined as
609. 24:32the number of frames or amount of data
610. 24:35that can be sent at the current time
611. 24:38this is always less than or equal to the
612. 24:40window size
613. 24:42so we are going to cover queueing and
614. 24:44traffic shaping on the next slides
615. 24:48for the cubing to improve link
616. 24:50utilization so to improve link
617. 24:52utilization
618. 24:54cisco has developed the qos or the
619. 24:57quality of service techniques to avoid
620. 24:58temporary congestion
621. 25:00and to provide preferential treatment of
622. 25:03critical applications
623. 25:05so qos mechanisms such as skilling and
624. 25:09scheduling
625. 25:10policing or limiting the access rate and
626. 25:13traffic shaping enables network
627. 25:15operators
628. 25:16to deploy and operate large-scale
629. 25:19networks
630. 25:20that efficiently handle both bandwidth
631. 25:22hungry such as multimedia and web
632. 25:24traffic
633. 25:25and mission-critical applications such
634. 25:27as hosted-based applications
635. 25:30so key types of viewing includes
636. 25:32priority queueing
637. 25:34you've got the custom queueing weighted
638. 25:36fair queueing
639. 25:38plus based weighted per queueing and low
640. 25:40latency queuing
641. 25:42you can go ahead and check the
642. 25:44supplementary videos
643. 25:45for additional information about viewing
644. 25:52traffic shaping and policing traffic
645. 25:55shaping and traffic policing
646. 25:57also referred to as the committed access
647. 25:59rate
648. 26:01are similar mechanisms in that both
649. 26:03inspect traffic
650. 26:05and take action based on various
651. 26:07characteristics of that traffic
652. 26:10so this characteristics can be based on
653. 26:13whether the traffic is over
654. 26:14under a given rate or is based on some
655. 26:18bits
656. 26:19in the ip packet header such as the dscp
657. 26:22or ip
658. 26:23precedents
659. 26:27now to summarize identifying one
660. 26:29technology considerations
661. 26:31so a one is a communications network
662. 26:34that covers a relatively broad
663. 26:36geographic area and carries a variety of
664. 26:39traffic
665. 26:40using transmission facilities that are
666. 26:42typically provided by the service
667. 26:44providers or sps
668. 26:47the multiple one transport technologies
669. 26:50vary in bandwidth
670. 26:52performance characteristics and costs
671. 26:55in one design enterprise edge
672. 26:57connectivity requirements influence the
673. 26:59trade-off
674. 27:00between the cost of bandwidth and
675. 27:03bandwidth efficiency