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Voice, Video, and Data Integration Version 2.0

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Module 10 1

Voice, Video, and Data 2 Integration 3

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10-2 Cisco Certified Network Associate Basics (CCNAB) v2.0 Copyright 2002, Cisco Systems, Inc.

Table of Contents 4

MODULE 10.......................................................................................................................1 5

VOICE, VIDEO, AND DATA INTEGRATION...................................................................1 6 OVERVIEW ......................................................................................................................................................3 7 10.1 EVOLUTION OF CONVERGED NETWORKING..................................................................................................4 8

Overview ....................................................................................................................................................4 9 10.1.1 Traditional Networks .........................................................................................................................5 10 10.1.2 Voice, Video, and Data Networks .......................................................................................................6 11 10.1.3 Voice, Video, and Data Integration.....................................................................................................8 12 10.1.4 Applications......................................................................................................................................9 13 10.1.5 Cisco IP Contact Center ..................................................................................................................11 14 Summary ..................................................................................................................................................14 15

10.2 CISCO AVVID .......................................................................................................................................15 16 Overview ..................................................................................................................................................15 17 10.2.1 Open Packet Telephony ...................................................................................................................16 18 10.2.2 End-to-End Architecture ..................................................................................................................17 19 10.2.3 Open Standards...............................................................................................................................18 20 10.2.4 Network Availability ........................................................................................................................20 21 10.2.5 Lower Total Cost of Ownership ........................................................................................................22 22 10.2.6 Branch Office Network ....................................................................................................................24 23 10.2.7 Campus Network .............................................................................................................................26 24 10.2.8 Wide-Area Network .........................................................................................................................28 25 Summary ..................................................................................................................................................29 26

10.3 VOICE QUALITY-OF-SERVICE ISSUES ........................................................................................................30 27 Overview ..................................................................................................................................................30 28 10.3.1 Common Issues with QoS .................................................................................................................31 29 10.3.2 Delay .............................................................................................................................................32 30 10.3.3 Jitter ..............................................................................................................................................33 31 10.3.4 Lost Packets....................................................................................................................................34 32 10.3.5 Echo...............................................................................................................................................35 33 10.3.6 Cisco IOS QoS Technology ..............................................................................................................36 34 Summary ..................................................................................................................................................38 35

10.4 VOICE-OVER-DATA TECHNOLOGIES..........................................................................................................39 36 Overview ..................................................................................................................................................39 37 10.4.1 Introduction to Voice and Data Networks ..........................................................................................40 38 10.4.2 Voice over Frame Relay...................................................................................................................41 39 10.4.3 Voice over ATM ..............................................................................................................................42 40 10.4.4 Voice over IP ..................................................................................................................................43 41 10.4.5 Voice-over-Data Technologies Comparison.......................................................................................45 42 Summary ..................................................................................................................................................46 43

SUMMARY.....................................................................................................................................................47 44 45

Copyright 2002, Cisco Systems, Inc. Module 10: Voice, Video, and Data Integration 10-3

Overview 46 The Internet is creating tremendous business opportunities for the enterprises. 47 Internet business solutions such as e-commerce, supply chain management, e-48 learning, and customer care are dramatically increasing productivity and 49 efficiency. 50

There is a lot of talk today about merging voice and data networks. This may be 51 referred to as multiservice networking or voice, video, and data integration or 52 just voice and data integration. They all refer to the same thing: merging 53 multiple infrastructures into one that carries all data, regardless of type. 54

The trends driving this integration initially are costsaving money. Significant 55 amounts of money can be saved by doing away with parallel infrastructures. In 56 the long run, though, new business applications are what will drive the 57 integration of data and voice. 58

This module describes the traditional separation of voice and data networks and 59 the new voice, video, and data technologies. This module introduces Cisco 60 AVVID (Architecture for Voice, Video and Integrated Data), which is an 61 enterprise architecture that provides the intelligent network infrastructure for 62 today's Internet business solutions. 63

You will also learn about the voice-over-data transport options (voice over IP 64 [VoIP], voice over Frame Relay [VoFR], and voice over ATM [VoATM]), with 65 reasons for choosing one option over another. 66

Upon completing this module, you will be able to: 67

Describe how traditionally voice, video, and data networks are 68 implemented and the benefits of voice, video, and data converged 69 networks 70

Describe the features and main building blocks of Cisco AVVID 71

Discuss issues with voice quality of service (QoS) 72

Describe voice-over-data technologies 73

Outline 74 This module contains these lessons: 75

Overview 76

Evolution of Converged Networking 77

Cisco AVVID 78

Voice Quality-of-Service Issues 79

Voice-over-Data Technologies 80

Summary 81

82

83


10.1 Evolution of Converged Networking 84

Overview 85 This lesson describes how traditionally voice, video, and data networks are 86 implemented and the needs for converged voice, video, and data networks. This 87 lesson also discusses the new applications for converged networks. In addition, this 88 lesson introduces the business and technical benefits of the Cisco IP Contact Center. 89 90

Objectives 91 Upon completing this lesson, you will be able to: 92 93

Describe how voice, video, and data networks are implemented traditionally 94

Describe voice, video, and data networks 95

Identify the benefits of converged voice, video, and data networks 96

Identify emerging applications for converged networking and their 97 functions 98

Identify the benefits of Cisco IP Contact Center 99

Outline 100 This lesson includes these sections: 101 102

Overview 103

Traditional Networks 104

Voice, Video, and Data Networks 105

Voice, Video, and Data Integration 106

Applications 107

Cisco IP Contact Center 108

Summary 109

110


10.1.1 Traditional Networks 110 Figure 1: Optical Business Drivers 111

112 113 Traditionally, separate networks have been provisioned within an enterprise for 114 data, voice, and video applications. These have been deployed autonomously and 115 operated in isolation, often implemented and managed by separate teams. 116 117 These separate networks encompass the enterprise local- and wide-area networks 118 (LANs and WANs), and have been built to interconnect private branch exchange 119 (PBX) equipment, H.320 videoconferencing equipment, and routers. The networks 120 have been provisioned over dedicated leased lines for PBX and H.320 video, with a 121 combination of leased lines, Frame Relay, and ATM for data. Figure [1] depicts a 122 typical deployment of these disparate networks. 123

Practice 124 1. True or False: Traditionally, an enterprise usually has a separate network for 125

voice, video, and data applications. 126 127

A. True ** 128 B. False 129 130 131

132


10.1.2 Voice, Video, and Data Networks 132 Figure 1: Voice, Video, and Data Networks 133

134 135 This use of disparate facilities for each application transport is extremely 136 inefficient. The volume of data traffic is growing faster than that of voice, driven by 137 emerging and evolving technological innovations such as the World Wide Web 138 (WWW), e-commerce, and applications such as videoconferencing or video 139 streaming utilizing Internet Protocol (IP) multicast. While growth rates vary by 140 country and carrier, it is certain that data transport will dominate telephony 141 networks. Data has already surpassed voice on some U.S. service provider networks. 142 It is the driving force behind global network growth. The challenge for the 143 enterprise is to optimize networking to carry data, voice, and video traffic. 144 145 It is widely accepted and acknowledged by the communications industry and 146 industry analysts as a whole that the IP will become the universal transport of the 147 future. The rapid adoption and migration of vendors to the utilization of IP as a 148 transport for data, voice, and video applications further endorses this transition to a 149 converged networking paradigm. This includes those vendors who have historically 150 used time-division multiplexing (TDM) infrastructures and relied upon old world 151 practices. 152 153 Converged networks are a continuing trend and this consolidation of data, voice, 154 and video is the natural evolution for multiservice networking. We have seen similar 155 evolutions before. The converged network is shown in Figure [1]. Utilizing IP as the 156 ubiquitous transport offers the enterprise significant statistical gains in bandwidth 157 efficiency, lower overall bandwidth requirements, ease of management, and the 158 ability to deploy new applications rapidly. On the LAN, data, voice, and, video 159 share a common infrastructure. 160 161 As shown in Figure [1], a converged network allows the enterprise network to 162 converge over a common IP transport. The number of WAN facilities is reduced, as 163

Cisco CallManager


is the number of devices required to terminate those facilities. Bandwidth can be 164 added incrementally and shared statistically between applications, adding efficiency 165 and reducing complexity. When voice is inactive, data can utilize the available 166 bandwidth; when voice or video applications are active, they can be guaranteed the 167 bandwidth required. 168

Practice 169 1. Utilizing IP as the ubiquitous transport does not offer which of the following 170

gains to enterprises? 171 172

A. Bandwidth efficiency 173 B. Higher overall bandwidth requirements ** 174 C. Ease of management 175 D. Ability to deploy new applications rapidly 176

177


10.1.3 Voice, Video, and Data Integration 177 Figure 1: Voice, Video, and Data Integration 178

179 180

181 The converged enterprise network for data, voice, and video will require the 182 appropriate infrastructure and design. Figure [1] depicts a converged network where 183 all data, voice, and video utilize IP as the transport; between sites the IP WAN is the 184 primary interconnect, with the Public Switched Telephone Network (PSTN) being 185 used as a secondary connectivity method. 186 187 Such a converged network will lower costs and provide enhanced quality options 188 for voice networking. It provides a highly scalable, reliable, and available network 189 that is adaptable and permits the rapid deployment of new and innovative 190 applications. Because the above network is based upon standards and open 191 competition, interoperability with other applications is assured. 192

Practice 193 1. Which of the following is true of a data, voice, and video converged network 194

utilizing IP as the transport? 195 196

A. Higher costs 197 B. Enhanced quality options for voice networking ** 198 C. Decreased bandwidth 199 D. Limited ability in adapting new applications 200

201

Cisco CallManager


10.1.4 Applications 201 Figure 1: Applications 202

203 204 Figure 2: Applications 205

206 207 An important facet of converged networking is the enabling of new applications. 208 Such emerging applications include desktop IP telephony, unified messaging, and 209 the Cisco IP Contact Centers. A converged network will offer the framework that 210 permits rapid deployment of these new technologies. 211 212

Cisco CallManager

Fax Messages

Unified Messaging In-and-Out Box


By using the Cisco CallManager, a PBX can be eliminated and replaced with IP 213 telephony over a converged network. As shown in Figure [1], the Cisco 214 CallManager provides call-control functionality and, when used in conjunction with 215 the IP telephone sets or a soft telephone application, can provide the PBX 216 functionality in a distributed and scalable fashion. Cisco CallManagers can be 217 networked via IP and provide fallback to the PSTN if required. 218 219 Today users have a wide range of communication and messaging mediums available 220 to them: telephones, cell phones, pagers, fax, voice mail, and e-mail. Each of these 221 requires distinct hardware and software components to function. Unified messaging 222 combines voice mail, e-mail, and fax into a single application suite. 223 224 With unified messaging, a single application can be used to store and retrieve an 225 entire suite of message types. Voice-mail messages stored as WAV files can be 226 downloaded as e-mail attachments while traveling, and a response can be recorded 227 and returned to the sender, all recipients, or an expanded list. E-mail can be 228 retrieved via a telephony user interface (TUI), converted from text to speech, and 229 reviewed from an airport lobby phone or cell phone. Infrastructure is decreased 230 because now a single application can provide voice, e-mail, and fax. Productivity is 231 increased because what were once disparate message types can be retrieved via the 232 most convenient-or the user's preferred-interface. 233 234 Cisco is able to offer unified messaging via its Cisco GateServer Series of products. 235 These products provide scalable solutions for service providers and the enterprise 236 via open, standards-based interfaces. Figure [2] depicts this unified messaging 237 model. 238

Practice 239 1. Unified messaging combines which of the following message types into a single 240

application suite? 241 242

A. E-Mail 243 B. Voice Mail 244 C. Fax 245 D. All of the above ** 246

247


10.1.5 Cisco IP Contact Center 247 Figure 1: Cisco IP Contact Center 248

249 250

Figure 2: Cisco IP Contact Center 251

252 253 The Cisco IP Contact Center (IPCC) solution combines data and voice technologies 254 to facilitate geographic independent multimedia customer interaction. This includes 255 customer interactions originating from multiple diverse contact channels, including 256 IP voice, TDM voice, Web, e-mail, and fax. Regardless of transport, whether the 257 Internet or the traditional PSTN, the Cisco IPCC fully integrated contact-center 258 architecture depicted in Figure [1] services all media types. The Cisco IPCC 259 architecture also provides a seamless migration path from the legacy call-center 260 infrastructure to the IP-empowered, multimedia contact center. 261 262

Videoconference

Integrated Data and Voice Single-User Model

Location Independence

E-Mail

E-Mail

Voice over IP

Prerouting

Softphone

Integrated Business Rules: IP Voice, TDM Voice, Web, E-Mail, and Fax

Softphone


The Cisco IPCC solution also enables server- and agent-level IP telephony to 263 coexist with traditional TDM-based networks, existing automated call 264 distribution/PBXs (ACD/PBXs), and installed desktop systems. The Cisco IPCC 265 solution enables an organization to take advantage of new IP-based applications 266 while preserving heterogeneous legacy investments and taking advantage of existing 267 IP data infrastructure. Thus Cisco IPCC deployment can be incremental, adding IP 268 telephony, new media channels, and new IP-based services at a rate that meets 269 business demands. 270 271 Cisco IPCC business benefits include: 272 273

Integrated multimedia queuing 274

Enterprise-wide contact management based on a single set of business rules 275 and supported by normalized consolidated reporting 276

Increased customer satisfaction through personalized customer interaction 277

Geographic independence of both agent resources and IP-based application 278 servers through the ubiquity of IP transport 279

Carrier-quality fault tolerance and system reliability 280

Scalability from single-site to multisite to network service provider services 281

Rapid solution deployment many times faster than traditional TDM 282 solutions 283

Single network, eliminating the overhead of multiple diverse data, voice, 284 and video networks 285

The physical topology of the Cisco IPCC as shown in Figure [2] is a solution that 286 can carry high-fidelity voice to agents throughout the enterprise network, and, on 287 that same connection, provide standard computer telephony integration (CTI) 288 applications as well as features such as Web collaboration, chat, and unified 289 messaging. 290 291 Technical advantages to the Cisco IPCC topology include: 292 293

Intelligent contact management 294

Enterprise-wide command and control 295

Network-level customer queuing, customer segmentation, and contact 296 distribution 297

Consistent service standards across diverse media channels 298

Scalable applications 299

Seamless migration path to IP-based voice applications 300

Easy and rapid deployment of remote agents 301

In addition to the improvement in development and deployment of new services and 302 applications through a converged IP infrastructure, a further benefit of this 303 technology is to offer users a simpler, integrated interface that presents information 304 consistently across multiple media channels. Users of this technology can, for 305 example, utilize a Web interface to research a product. When questions arise, they 306 can click to talk and be connected to a knowledgeable and highly skilled agent 307 who is familiar with that product and has the same screen display, avoiding a 308


multistep and multicall process. Similar schemes can be used for banking over the 309 Web, avoiding the need to enter the account number multiple times and connecting 310 to an agent only when a customer desires or an automated response is insufficient. 311 312 The Cisco IPCC combines IP telephony technology, intelligent contact management 313 technology, as well as legacy call-center applications and hardware into a unified 314 platform to implement an organization's business rules and objectives. 315 316

Practice 317 1. Which of the following is a business benefit of Cisco IPCC? 318 319

A. Seamless migration path to IP-based voice applications 320 B. Consistent service standards across diverse media channels 321 C. Increased customer satisfaction through personalized customer 322

interaction ** 323 D. Intelligent contact management 324

325


Summary 325 This section summarizes the key points you learned in this lesson. 326 327

Traditionally, an enterprise has separate networks for data, voice, and video 328 applications. Those networks are usually operated in isolation, and often are 329 implemented and managed by separate teams. 330

IP is considered to be the universal transport of the future. 331

A voice, video, and data converged network could lower costs and provide 332 enhanced quality options for voice networking. 333

An important facet of converged networking is the enabling of new 334 applications, such as desktop IP telephony, unified messaging, and the 335 Cisco IP Contact Center. 336

The Cisco IP Contact Center (IPCC) solution combines data and vice 337 technologies to facilitate geographic independent multimedia customer 338 interaction. 339

340

341

342 343


10.2 Cisco AVVID 344

Overview 345 This lesson describes the building blocks and the features of Cisco AVVID 346 (Architecture of Voice, Video and Integrated Data). 347 348


Describe the features of Cisco AVVID 352

Identify the main building blocks of Cisco AVVID 353

Identify the key benefit of Cisco AVVID 354

Describe how the network redundancy is achieved in Cisco AVVID 355

Identify the factors that lower cost of data networking equipment ownership 356

Describe the branch office requirements for a converged network 357

Describe the campus/regional office requirements for a converged network 358

Describe the requirements for a converged WAN 359


Overview 363

Open Packet Telephony 364

End-to-End Architecture 365

Open Standards 366

Network Availability 367

Lower Total Cost of Ownership 368

Branch Office Network 369

Campus Network 370

Wide-Area Network 371

Summary 372

373


10.2.1 Open Packet Telephony 373 Figure 1: Open Packet Telephony 374

375 376 Cisco AVVID (Architecture for Voice, Video and Integrated Data) brings to 377 multiservice networking a standards-based, open-systems architecture for converged 378 networking. Cisco AVVID is the continuing evolution of the five-phase plan 379 depicted in Figure [1] for enterprise multiservice networking that has successfully 380 delivered the framework for an open, multiservice architecture. 381 382 Cisco AVVID is complementary and synergistic with the open packet telephony 383 (OPT) initiative. Whereas Cisco OPT focuses on service providers and the benefits 384 of converged data and voice over a common packet transport, Cisco AVVID is an 385 enterprise initiative for integrated data, voice, and video over a common IP 386 transport. 387 388 The architecture comprises three distinct building blocks: infrastructure such as 389 switches and routers, applications such as call control, and clients such as fixed and 390 wireless IP telephones, H.323 videoconferencing equipment, and PCs. Each of these 391 building blocks is discussed in more detail in a subsequent section. The end result of 392 such an architectural model is a multiservice ecosystem that is scalable, highly 393 available and resilient, open, and adaptable. 394

Practice 395 1. Cisco AVVID is the continuing evolution of the ____-phase plan. 396 397

A. Three 398 B. Four 399 C. Five ** 400 D. Six 401

402

Policy-Based End-to-End

CallManagement

QoS CallManagement

Layer 1-3 Integration Networked Availability

Management


10.2.2 End-to-End Architecture 402 Figure 1: End-to-End Architecture 403

404 405 Cisco AVVID is an end-to-end architecture that includes three distinct components: 406 infrastructure, applications, and clients. Figure [1] depicts the components of the 407 architecture. As with any architecture, Cisco AVVID relies upon a strong and stable 408 foundation. This foundation is built upon the multiprotocol routers and multilayer 409 LAN switches that are used as building blocks for enterprise networks. 410 411 Cisco has a range of products that have the ability to terminate both analog and 412 digital voice interfaces for integration with a legacy PBX or connection to the 413 PSTN. With IP telephony expanding beyond simple toll-bypass applications to the 414 desktop, LANs need to provide the prerequisite quality of service (QoS) and 415 bandwidth required to support converged network applications such as voice and 416 video. 417

Practice 418 1. Which of the following is not a building block of the Cisco AVVID? 419 420

A. Infrastructure 421 B. Cables ** 422 C. Applications 423 D. Clients 424

425

Softphone

Cisco CallManagerServer


10.2.3 Open Standards 425 Figure 1: Open Standards 426

427 428 Cisco is promoting the use and adoption of open standards and is participating 429 actively in the definition and approvals process for numerous standards and open 430 protocols in this arena. Cisco Systems adopts these standards as they emerge and 431 mature and also offers prestandard implementations to the market where no defined 432 standard exists. Every effort is made to ensure that the gateways, applications, and 433 clients produced integrate and operate seamlessly with third-party products. 434 435 Examples of these protocols include the existing and emerging standards-based 436 protocols for call control: H.323, the Simple Gateway Control Protocol (SGCP), the 437 Media Gateway Control Protocol (MGCP), and the Session Initiation Protocol 438 (SIP). 439 440 Further examples of open standards currently being adopted by the 441 telecommunications industry are the Telephony Application Programmable 442 Interface (TAPI) and the Java Telephony Application Programmable Interface 443 (JTAPI). These protocols are used to communicate between applications such as the 444 Cisco CallManager, providing IP PBX functionality, and unified messaging 445 products such as the Cisco GateServer products. This open and standards-based 446 interface model, depicted in Figure [1], is in direct contrast to the proprietary 447 interfaces of legacy PBX equipment. 448 449 The use of open standards and the promotion of multivendor collaboration and 450 interoperability are a key benefit of Cisco AVVID. The architecture allows the 451 integration of products from multiple vendors to create a customized solution. No 452 single vendor can provide a solution that fits all requirements for data, voice, and 453 video. Often specialized applications are designed and implemented only by a single 454 company and need to be integrated with the overall solution. The adoption of open 455 standards creates an ecosystem that actively promotes a model of integration. 456 457

Cisco CallManager

Softphone

Infrastructure Cisco IOS Software-Based Network Services


Practice 458 1. Which of the following is a key benefit of Cisco AVVID? 459 460

A. The use of open standards 461 B. The promotions of multivendor collaboration 462 C. The promotion of multivendor interoperability 463 D. All of the above ** 464

465 466


10.2.4 Network Availability 466 Figure 1: Network Availability 467

468 469 The PBX has evolved over many years to a device perceived as highly reliable, 470 performing basically one function and one function onlythe switching of voice 471 calls with some added services such as transfer and conference. Each vendor 472 maintains a proprietary architecture to ensure that when a customer is using a 473 particular brand of switch, the customer needs to continue using that same brand of 474 device to maintain feature parity. 475 476 The system is deemed available by the user if dial tone is present when the handset 477 is lifted. This is only a subjective measurement of the availability of dial tone. If a 478 busy signal is received when a long-distance number is dialed, there is no way to 479 know whether all circuits are busy, the person called is busy, or the link to the 480 PSTN is down. All of these situations affect availability of the system to the user. In 481 the data arena, they would be factored into system, as opposed to box, availability. 482 483 In contrast, the world of data networking presents a picture where availability is 484 designed into a distributed system rather than a box. Redundancy is available in the 485 individual hardware components for services such as power and supervisor 486 modules. Network redundancy is, however, achieved with a combination of 487 hardware, software, and intelligent network design practices. Figure [1] shows a 488 typical enterprise network topology. 489 490 In Figure [1], network redundancy is achieved at many levels. Physical connections 491 exist from the edge devices where IP telephones and PCs are attached to two 492 spatially diverse aggregation devices. If an aggregation device fails or connectivity 493 is lost for any reason (such as fiber cut or power outage), cutover of traffic to the 494 other device is possible-essentially without loss. This is also true of the WAN and 495 PSTN connections. Clusters of Cisco CallManagers can be provisioned to provide 496 resilient call control; if any device within the cluster fails, the other servers pick up 497 the load. These designs can provide 99.999-percent reliability. 498 499

Cisco CallManagerCluster

Cisco CallManagerCluster


Practice 500 1. Which of the following statement correctly describe network redundancy? 501 502

A. Network redundancy is achieved with a combination of hardware, 503 software, and intelligent network design practices. ** 504

B. Network redundancy can be achieved with good hardware equipment. 505 C. Network redundancy can only be achieved through intelligent network 506

practices. 507 D. Network redundancy can only be done in user level. 508

509 510


10.2.5 Lower Total Cost of Ownership 510 Figure 1: Lower Total Cost of Ownership 511

512 513 While data networking has evolved to open, distributed, standards-based systems, 514 the telephony infrastructure has changed little in the past 20 years, and those 515 economies and efficiencies associated with open standards and competition have 516 been impossible to attain. After a PBX vendor has been selected and the product has 517 been implemented, the proprietary and closed architecture of that PBX effectively 518 prevents multivendor interoperability at anything other than basic levels. This 519 scenario has kept the price per port of PBX systems relatively flat for recent years, 520 and also shackled customers to the PBX vendor. 521 522 Contrast the above to data networking and the picture is very different. Moore's Law 523 has demonstrated that the price/performance of semiconductors doubles every 16 524 months. These savings have caused the cost of data networking equipment to fall 525 rapidly over time, while performance has increased exponentially. These benefits 526 translate into reduce prices for customers. 527 528 Consider, for example, the shared 10-Mbps Ethernet connection or 4-Mbps Token 529 Ring to the desktop that was the norm until recently. Now a 100-Mbps connection 530 to the desktop is typical and the price is less than that paid for shared 10-Mbps 531 Ethernet only a few years ago. This represents a 20-plus-fold increase in available 532 bandwidth, for a fraction of the cost. 533 534 Other factors that lower costs include the reduction of wide-area facility 535 requirements, fewer devices to manage and maintain, and simpler moves, additions, 536 and changes. This scenario results in a lower training and staffing cost associated 537 with a simplified and converged infrastructure. Figure [1] illustrates this duplicity in 538 economy between old and New World architectures. 539

Price Per Seat

Proprietary System (PBX) per-Seat Pricing Versus Open System (Ethernet Switch) Market Characteristics


Practice 540 1. Which of the following is a factor that lowers cost of data networking 541

equipments ownership? 542 543

A. Increasing on the performance of the semiconductors ** 544 B. Increasing requirements for wide-area facility 545 C. Increasing requirements for devices management 546 D. None of the above 547

548 549

550


10.2.6 Branch Office Network 550 Figure 1: Branch Office Network 551

552 553 In the branch location, the infrastructure comprises a router with voice capabilities 554 to interface with the PSTN for off-net and overflow voice calls. Figure [1] depicts a 555 typical branch office of 100 or fewer users. The primary transport for intersite on-556 net voice calls is the IP WAN. The router provides advanced quality of service 557 (QoS) capabilities to ensure high voice quality as well as native multicast 558 capabilities for video applications. Because IP is independent of the WAN media, 559 leased lines, Frame Relay, Asynchronous Transfer Mode (ATM), or emerging last-560 mile technologies such as cable and digital subscriber line (DSL) could be used. 561 562 Note: On-net calling refers to calls that stay on a customer's private network, 563 traveling by private line from beginning to end. Off-net calling refers to phone calls 564 that are carried in part on a private network but are destined for a phone that is not 565 on the network. That is, some part of the journey of the conversation will be over 566 the PSTN or someone else's network. 567 568 LAN infrastructure can be provisioned using a Cisco Catalyst Multilayer Switch. 569 Cisco Catalyst line cards provide inline power to next-generation IP telephones, and 570 customers can choose to connect both the IP telephone and PC to a switched port 571 (via an integrated 10/100 switch in the telephone) or use separate ports for PC and 572 telephone. Again the prerequisite classification, queuing, and buffer management 573 features are available with the Cisco Catalyst switches. 574 575

Cisco CallManager(s)


Call control and integrated voice mail can be provided for the branch office in a 576 packaged solution. Setup can be optionally augmented with a second platform for 577 additional redundancy. Client applications can be provided by IP telephones or 578 softphones installed on PCs. 579

Practice 580 1. Which of the following devices can be used in branch office to interface with 581

the PSTN or next generation IP telephones? (Check all that apply.) 582 583

A. A router with voice capabilities ** 584 B. A bridge 585 C. A Cisco Catalyst Multilayer Switch ** 586 D. A hub 587

588


10.2.7 Campus Network 588 Figure 1: Campus Network 589

590 591 The next logical step is to migrate to a converged network in the regional office, 592 campus, and metropolitan-area networks (MANs). The requirements for QoS and 593 reliability do not change; only the scale of the solution changes. Figure [1] 594 illustrates a typical enterprise campus network design and is used to discuss the 595 necessary building blocks for a Cisco AVVID deployment. Although Figure [1] 596 depicts a large campus, the modular design allows design philosophy to be scaled 597 from 100s to 10,000s of stations with no loss of performance or resiliency. 598 599 As in the branch example, Cisco routers provide the required WAN and PSTN 600 access. Here these routers are required to scale to support the incoming and tandem 601 traffic from many smaller branch locations. LAN infrastructure is provisioned using 602 Cisco Catalyst Series of switches. Here again the required classification, queuing, 603 and buffering schemes are available. The design model shown is hierarchical, giving 604 predictable and scalable performance, and also ensuring fast convergence in case a 605 component fails. Telephones can be connected to this switched infrastructure at the 606 access layer either in series with a PC or via dedicated switched ports. 607 608 The Cisco CallManager and unified messaging applications in this instance can be 609 located on separate, dedicated servers. This setup is depicted as the server-farm 610 building block. The Cisco CallManager supports a clustering scheme that provides a 611 distributed scalable and highly available model. As additional users are brought on 612 line, simply adding a new server to the cluster adds capacity to the system. In a 613 similar fashion, voice messaging or unified messaging can be provided via the 614 Amteva products installed on dedicated servers. As increased capacity is added, 615 more servers are added to the system. Messages are stored on an industry-standard 616 message store. 617

Layer 2 Switch

Layer 3 Switch

Layer 3 Switch

Layer 3 Switch


Practice 618 1. In a campus network, the Cisco CallManager and unified messaging 619

applications can be located on separate, dedicated servers. This setup is 620 depicted as? 621

622 A. Farm-farm building block 623 B. Server-farm building block ** 624 C. Server-client building block 625 D. Farm-client building block 626

627


10.2.8 Wide-Area Network 627 Figure 1: Wide-Area Network 628

629 630 For multiservice traffic to traverse a converged WAN, the network must support and 631 supply the prerequisite QoS features. These features are discussed in more detail in 632 a subsequent lesson. In addition, the design and dimensioning of the WAN must be 633 synergistic with the traffic profiles, business requirements, and circuit tariffs. 634 635 Cisco Systems recommends that WANs be built using a hierarchical model to allow 636 the most cost-effective platforms to be provisioned at the edge. At regional and 637 headquarter locations, higher-performance platforms can be deployed to allow the 638 scaling of throughput and Layer 3 services. Figure [1] represents the WAN model. 639 640 In addition to the above design philosophy, the WAN bandwidth requirements need 641 to be adequately provisioned. As the requirements for data traffic outstrip those of 642 voice, the percentage of the wide-area bandwidth required for voice decreases, 643 lowering costs. It is imperative that the WAN links be provisioned to support the 644 minimum requirements for data plus the bandwidth required for voice and video 645 traffic. When other applications are quiescent, the bandwidth is available for data. 646

Practice 647 1. Cisco Systems recommends which of the model to be used to build a converged 648

WAN to allow the most cost-effective platforms to be provisioned at the edge? 649 650

A. The ring model 651 B. The linear model 652 C. The mesh model 653 D. The hierarchical model ** 654

655



Cisco AVVID in an enterprise initiative for integrated data, voice, and 659 video over a common IP transport. 660

Cisco AVVID is an end-to-end architecture that includes three components: 661 infrastructure, applications, and clients. 662

A key benefit of Cisco AVVID is the use of open standards and the 663 promotion of multivendor collaboration and interoperability. 664

Network redundancy is achieved with a combination of hardware, software, 665 and intelligent network design practices. 666

The increasing performance of semiconductors has caused the cost of data 667 networking equipment to fall rapidly over time. 668

669


10.3 Voice Quality-of-Service Issues 670

Overview 671 This lesson explains issues with voice QoS. 672


Describe the effects of QoS in voice, video, and data integration networks 676

Discuss solutions to QoS problem: delay 677

Discuss solutions to QoS problem: jitter 678

Discuss solutions to QoS problem: lost packets 679

Discuss solutions to QoS problem: echo 680


Overview 684

Common Issues with QoS 685

Delay 686

Jitter 687

Lost Packets 688

Echo 689

Summary 690

691 692

693


10.3.1 Common Issues with QoS 693 Figure 1: QoS Issues 694

695 696 QoS provides the ability to prioritize applications and allocate resources across the 697 network to ensure the delivery of mission-critical applications, especially in heavily 698 loaded environments. An analogy is the car-pool lane on the highway. Mission-699 critical applications receive highest priority, so they travel in the diamond (car-pool) 700 lane. All other traffic receives equal treatment, so it travels in the low-priority lanes. 701 702 The reduced cost and bandwidth savings that can be realized in voice-over-packet 703 networks carry with them some QoS issues that are unique to packet networks. In a 704 circuit-switched or TDM environment, bandwidth is dedicated, making QoS 705 implicit. In a packet-switched environment, all kinds of traffic are mixed in a store-706 and-forward manner. So, in a packet-switched environment, a need exists to devise 707 schemes to prioritize real-time traffic. 708 709 In an integrated voice and data network, QoS is essential to ensure the same high-710 quality voice transmissions as in the traditional circuit-switched environment. QoS 711 issues for voice may be handled by voice-over-IP (VoIP), voice-over-ATM 712 (VoATM), or voice-over-Frame Relay (VoFR) standards, or by an internetworking 713 device. Some solutions to these QoS issues are discussed in the following sections. 714

Practice 715 1. Which of the following standards may handle QoS issues for voice? 716 717

A. FDDI 718 B. IPX 719 C. VoIP ** 720 D. Token Ring 721

722


10.3.2 Delay 722 Figure 1: QoS Issue Delay 723

724

725 726 Delay causes two problems. 727 728

EchoEcho is caused by the signal reflections of the speaker's voice from 729 the far-end telephone equipment back into the speaker's ear. Echo becomes 730 a significant problem when the round-trip delay becomes greater than 50 731 milliseconds (ms). 732

Talker overlapTalker overlap becomes significant if the one-way delay 733 becomes greater than 250 ms. It is recommended to keep one-way delay 734 under 150 ms. 735

736 Solution 737 Minimize the end-to-end delay budget, including the accumulation delay, processing 738 delay, and network delay through sophisticated queuing techniques. 739

Practice 740 1. Which of the following problems is caused by delay? 741 742

A. Talker overlap ** 743 B. Lost packets 744 C. Jitter 745 D. Signal reflection 746

747 748 749

750

Priority Queue

Configurable Queues


10.3.3 Jitter 750 Figure 1: QoS Issue Jitter 751

752 753 Jitter relates to variable interpacket timing caused by the network that a packet 754 traverses. Removing jitter requires collecting packets and holding them long enough 755 to allow the slowest packets to arrive in time to be played in the correct sequence, 756 causing an additional delay. 757 758 Solution 759 Adjust the jitter buffer size to minimize jitter. 760 761

On an ATM network, the approach is to measure the variation of packet 762 levels over a period of time and incrementally adapt the buffer size to match 763 the calculated jitter. 764

On an IP network, the approach is to count the number of packets 765 successfully processed and adjust the jitter buffer to target a predetermined 766 allowable late packet ratio. 767

Practice 768 1. Which of the following is a solution to the problem caused by jitter? 769 770

A. Minimize the end-to-end delay budget 771 B. Send redundant information 772 C. Adjust the jitter buffer size ** 773 D. Use jitter-cancellation techniques 774

775 776

Jitter relates to variable interpacket timing caused by the network that a packet traverses.


10.3.4 Lost Packets 776 Figure 1: QoS Issue Lost Packets 777

778 779 Depending on the type of packet network, lost packets can be a severe problem. 780 Because IP networks do not guarantee service, they will usually exhibit a much 781 higher incidence of lost voice packets than ATM networks. 782 783 Solution 784 Although dropped packets are not a problem for data (because of retransmission), 785 they cause a significant problem for voice applications. To compensate, voice-over-786 packet software can either interpolate for lost speech packets by replaying the last 787 packet or it can send redundant information at the expense of bandwidth utilization. 788

Practice 789 1. ______ networks usually exhibit a much higher incident of lost packets than 790

______ networks. [Drag and drop the network types to an appropriate location.] 791 792

IP ATM 793 794

795


10.3.5 Echo 795 Figure 1: QoS Issue -- Echo 796

797 798 Echo is present even in a conventional circuit-switched telephone network. This 799 presence is typically acceptable because the round-trip delays through the network 800 are smaller than 50 ms and the echo is masked by the normal side tone that every 801 telephone generates. 802 803 Echo is a problem in voice-over-packet networks because the round-trip delay 804 through the network is almost always greater than 50 ms. For this reason, echo-805 cancellation techniques must be used. 806 807 Echo-cancellation techniques are used to compare voice data received from the 808 packet network with voice data being transmitted to the packet network. The echo 809 from the telephone network hybrid is removed by a digital filter on the transmit path 810 into the packet network. 811

Practice 812 1. Which problem is remedied by a digital filter on the transmit path into the 813

packet network? 814 815

A. Packet loss 816 B. Echo ** 817 C. Jitter 818 D. Delay 819

820 821

822


10.3.6 Cisco IOS QoS Technology 822 Figure1: Congestion Management 823

824 825

Figure2: Traffic Shaping and Policing 826

827 828 Cisco IOS Software provides QoS features and solutions for addressing the diverse 829 needs of voice, video, and data applications. Cisco IOS QoS technology lets 830 complex networks control and predictably service a variety of networked 831 applications and traffic types. Small to medium businesses, enterprises, and service 832 providers all benefit from deploying Cisco QoS on their networks. Bandwidth, 833 delay, jitter, and packet loss can be effectively controlled. By ensuring the desired 834 results, the QoS features lead to efficient, predictable services for business-critical 835 applications. 836 837 Using the rich QoS feature set in Cisco IOS Software, businesses can build 838 networks that conform to either the Internet Engineering Task Force (IETF) 839 Integrated Services (IntServ) model or the Differentiated Services (DiffServ) model. 840 Cisco IOS QoS features also provide value-added functionality such as network-841 based application recognition (NBAR) for classifying traffic on an application basis, 842 a service assurance agent (SAA) for end-to-end QoS measurements, and Resource 843 Reservation Protocol (RSVP) signaling for admission control and reservation of 844 resources. 845


846 Key Cisco IOS Software QoS categories and features include: 847 848

Classification 849

Congestion management (see Figure [1]) 850

Congestion avoidance 851

Traffic shaping and policing (see Figure [2]) 852

Signaling 853

RSVP, QoS policy propagation on BGP (QPPB) 854

Link efficiency mechanisms 855

Practice 856 1. Identify the Cisco IOS Software QoS categories and features: (Check all that 857

apply.) 858 859

A. Congestion management ** 860 B. Signaling ** 861 C. Scalable applications 862 D. Intelligent contact management 863 E. Traffic shaping and policing ** 864 F. Seamless migration path to IP-based voice applications 865 866

867 868 869 870 871 872 873 874

875 876

877



In a circuit-switched or TDM environment, bandwidth is dedicated, making 880 QoS implicit. 881

In a packet-switched environment, all kinds of traffic are mixed in a store-882 and-forward manner. Consequently, packet-switched networks face voice 883 quality issues that circuit-switched networks do not, including delay, echo, 884 jitter, and lost packets. 885

Delay causes two problems: echo and talker overlap. 886

One solution to the problem caused by jitter is to adjust the jitter buffer 887 size. 888

Because IP networks do not guarantee service, they usually exhibit a much 889 higher incidence of lost voice packets than ATM networks. 890

Echo is more serious on a packet-switched telephone network than with 891 conventional telephony. 892

The use of QoS techniques throughout the network enables effective 893 transmission of voice-over-packet switched networks. Through careful use 894 of QoS techniques, network designers can overcome these quality issues 895 and produce circuit quality voice at a fraction of the cost. 896

897


10.4 Voice-over-Data Technologies 898

Overview 899 This lesson explains various types of voice-over-data technologies. 900 901


List examples of integrated voice, video, and data networks 905

Describe VoFR technology 906

Identify benefits of VoATM technology 907

Describe VoIP technology 908

Compare and contrast voice-over-data technology 909

Outline 910 This lesson includes the following sections: 911 912

Overview 913

Introduction to Voice and Data Networks 914

Voice over Frame Relay 915

Voice over ATM 916

Voice over IP 917

Voice over Data Technologies Comparison 918

Summary 919

920

921


10.4.1 Introduction to Voice and Data Networks 921 Figure1: Voice and Data Networks 922

923 924 Integrated voice and data networks support a variety of applications, all of which 925 are designed to replace leased lines and lower costs. A voice-capable router can 926 function as a local phone system for intra-office calls. In Figure [1], a user dials a 927 phone extension that is located in the same office. The voice-capable router routes 928 the call to the appropriate destination. A voice-capable router can also function as a 929 phone system for inter-office calls and can route calls within an enterprise network. 930 931 Voice-capable routers on a WAN can replace tie trunks between remote locations, 932 thereby saving the cost of tie trunks. In essence, the voice-capable router on either 933 side of the ATM, Frame Relay, or High-Level Data Link Control (HDLC) WAN 934 connection is configured as a tie trunk. The router then routes incoming and 935 outgoing calls through the PBX. 936

Practice 937 1. The functions of voice-capable routers include: 938 939

A. They can function as a local phone system for inter-office calls. 940 B. They can route calls within an enterprise network. 941 C. They can route incoming and outing calls through PBX. 942 D. All of the above ** 943

944


10.4.2 Voice over Frame Relay 944 Figure1: How VoFR Works 945

946 947 Voice-over-Frame Relay (VoFR) technology consolidates voice and voice-band data 948 (including fax and analog modems) with data services over a Frame Relay network. 949 VoFR allows PBXs to be connected using Frame Relay PVCs. The goal is to 950 replace leased lines and lower costs. With VoFR, customers can easily increase 951 their link speeds to their Frame Relay service or their committed information rate 952 (CIR) to support additional voice, fax, and data traffic. 953 954 Note: CIR is the rate at which a Frame Relay network agrees to transfer information 955 under normal conditions, averaged over a minimum increment of time. Measured in 956 bits per second (bps), CIR is one of the key negotiated tariff metrics. 957 958 A voice-capable router connects both a PBX and a data network to a public Frame 959 Relay network. A voice-capable router includes a voice Frame Relay adapter 960 (VFRAD) or a voice/fax module that supports voice traffic on the data network. 961 962 Sophisticated queuing techniques ensure QoS in voice over Frame Relay. 963 964 Frame Relay provides the following benefits: 965 966

Popular transport for multiservice networks because Frame Relay networks 967 are common in many areas 968

Cost-effective service that supports bursty traffic well 969

Prioritization of voice frames over data frames to guarantee QoS 970

Practice 971 1. VoFR: 972 973

A. Provides popular transport for multiservices networks 974 B. Consolidates voice and voice-band data (including fax and analog 975

modems) with data services 976 C. Provides cost-effective service that support bursty traffic well 977 D. All of the above ** 978

979


10.4.3 Voice over ATM 979 Figure 1: How VoATM Works 980

981 982 Voice over ATM (VoATM) is an ideal transport for multiservice networks, 983 particularly for customers who already have an ATM network installed. ATM 984 handles voice, video, and data equally well. A key benefit of ATM is its inherent 985 design for handling the unique network transmission requirements of voice, video, 986 and data traffic. 987 988 ATM has several mechanisms for controlling delay and delay variation through its 989 support for QoS, virtual-circuit queuing, and small, fixed-length cells. QoS enables 990 traffic to be provisioned with specific bandwidth and delay-variation guarantees. 991 Virtual-circuit queuing treats each traffic stream differently; thus, for example, 992 voice traffic can be allocated priority over delay-insensitive traffic. The 53-byte 993 ATM cells reduce queuing delay and delay variations associated with variable-sized 994 packets as well as reduce delays through intermediate switches. 995

Practice 996 1. True or False: Voice over ATM (VoATM) is an ideal transport for multiservice 997

networks. 998 999

A. True ** 1000 B. False 1001

1002 1003


10.4.4 Voice over IP 1003 Figure 1: Circuit-Switched Voice and IP Telephony Comparison 1004

Circuit-Switched Voice IP Telephony Moves often require cable checks, phone labels, and switch configuration updates.

Simple moves, adds, and changes are performed through Dynamic Host Configuration Protocol (DHCP) and autoregistration.

Circuit-switched voice offers limited access to signaling controller or handsets.

IP telephony can deploy homegrown third-party voice applications.

Circuit-switched voice requires a rigid homogenous network (adding capabilities is difficult and expensive).

IP telephony operates in a heterogeneous network.

Circuit-switched voice requires proprietary handsets.

IP telephony uses open handsets.

Circuit-switched voice operates multiple proprietary message stores.

IP telephony provides a unified message store infrastructure.

1005 Figure 2: 1006

1007 1008 Voice is an application that runs over the Open System Interconnection (OSI) model 1009 just like any other application. Voice information is encapsulated by headers as it 1010 passes through the OSI stack and then de-encapsulated on the receiving side. 1011 1012 The proliferation of Internet usage and emerging dominance of the IP protocol have 1013 created the backdrop for the newest voice-over-data applicationInternet 1014 telephony. A comparison of circuit-switched voice and IP telephony is shown in 1015 Figure [1]. In order to ensure high-quality, interoperable vendor implementations of 1016 telephony-based communications over IP data networks, the Voice over IP Forum 1017 was founded by Cisco in May 1996 and is currently chaired by Cisco. 1018 1019 Customers can choose VoIP as their voice-transport medium when they need a 1020 solution that is simple to implement, offers voice and fax capabilities, and handles 1021


phone-to-computer voice communications (see Figure [2]). One of the key benefits 1022 of VoIP is that it enables the customer to take advantage of the many features 1023 available with IP telephony. 1024

Practice 1025 1. Match each characteristic with either circuit-switched voice or IP telephony. 1026 1027

A. Has the ability to deploy homegrown third-party voice applications. 1028 B. Requires a rigid homogenous network. 1029 C. Offers limited access to signaling controller or handsets. 1030 D. Operates in a heterogeneous network. 1031

1032 Circuit-switched voice A B C D 1033 IP Telephony A B C D 1034

1035


10.4.5 Voice-over-Data Technologies Comparison 1035 Figure 1: How Packet Technologies Stack Up for Voice 1036

1037 1038 Frame Relay, ATM, and IP are popular voice-over-data technologies that have 1039 developed to meet the expanding needs of today's voice-over-data applications. 1040 1041 Each technology has its advantages and its limitations. 1042 1043

Frame Relay services are widely available and have been proven cost-1044 effective in most networks. Unfortunately, Frame Relay tops out at T1/E1 1045 speeds. 1046

Although ATM is considered to be a technology that will revolutionize the 1047 way networks are designed and managed, its services are still limited in 1048 scope and its equipment has been costly. 1049

IP allows users to take advantage of the many features available with IP 1050 telephony; however, this connectionless technology is the least 1051 deterministic. 1052

Practice 1053 1. Match each voice-over-data technology with its associated limitation. 1054 1055

A. Tops out at T1/E1 speeds 1056 B. Has limited services and costly equipment 1057 C. Is the least deterministic 1058

1059 Frame Relay A B C 1060 ATM A B C 1061 IP A B C 1062

1063 1064

1065

Standards in place



Integrated voice and data networks support a variety of applications, all of 1069 which are designed to replace leased lines and lower costs. 1070

VoFR is an inexpensive and easy-to-deploy service because of the wide 1071 availability of Frame Relay services. 1072

VoATM is an ideal transport for multiservice networks, particularly for 1073 customers who already have an ATM network installed. 1074

VoIP offers the capability to easily integrate advanced IP telephony 1075 features. 1076

1077

1078 1079


Summary 1080 This module includes these key points: 1081 1082

An integrated voice and data network offers many benefits over traditional 1083 telephony, including improved utilization of bandwidth, lower costs to 1084 maintain a single network, and more capability for added value services. 1085

Cisco AVVID brings to multiservice networking a standards-based, open-1086 systems architecture for converged networking. 1087

The use of QoS techniques throughout the network enables effective 1088 transmission of voice-over-packet switched networks. Some of the QoS 1089 issues customers face include delay, jitter, lost packet, and echo. 1090

The voice-over-data transport options include VoIP, VoFR, and VoATM. 1091 Each technology is developed to meet the expanding needs of todays voice-1092 over-data applications, and each has its advantages and its limitations. 1093

VoFR provides popular transport for multiservice networks and cost-1094 effective service that support bursty traffic well. 1095

VoATM handles voice, video, and data equally well. 1096

VoIP offers the capability to easily integrate advanced IP telephony 1097 features. 1098

CCNAB: Module 10 - Voice, Video, and Data IntegrationCopyright and DisclaimerTable of ContentsModule Overview10.1 Evolution of Converged NetworkingOverview10.1.1 Traditional Networks10.1.2 Voice, Video, and Data Networks10.1.3 Voice, Video, and Data Integration10.1.4 Applications10.1.5 Cisco IP Contact CenterSummary

10.2 Cisco AVVIDOverview10.2.1 Open Packet Telephony10.2.2 End-to-End Architecture10.2.3 Open Standards10.2.4 Network Availability10.2.5 Lower Total Cost of Ownership10.2.6 Branch Office Network10.2.7 Campus Network10.2.8 Wide-Area NetworkSummary

10.3 Voice Quality-of-Service IssuesOverview10.3.1 Common Issues with QoS10.3.2 Delay10.3.3 Jitter10.3.4 Lost Packets10.3.5 Echo10.3.6 Cisco IOS QoS TechnologySummary

10.4 Voice-over-Data TechnologiesOverview10.4.1 Introduction to Voice and Data Networks10.4.2 Voice over Frame Relay10.4.3 Voice over ATM10.4.4 Voice over IP10.4.5 Voice-over-Data Technologies ComparisonSummary

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