State of Computer Telephony 97: Beyond the Expo

The Computer Telephony business is dead serious in its quest to offer products and services that feature the best of both worlds from which it was born: the phone and computer industries.

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Pause for even a brief moment in this rapidly changing industry, you mightmiss something

Compared with the average button-down computer-equipment show, the ComputerTelephony (CT) Expo is wild. As evidenced by the inflaTable flying pink pigs outfront, the expo’s tone is less serious than even an Internet convention.

But the CT business is dead serious in its quest to offer products andservices that feature the best of both worlds from which it was born: the phoneand computer industries. This hybrid business is growing rapidly. ComputerTelephony Magazine and other industry sources estimate that it’s a $6billion industry. Certainly, Lucent Technologies believes CT's a seriousbusiness; the company just spent $1.5 billion to buy Octel, a longtime providerof voicemail and CT equipment.

The CT industry is more mature and more standardized than it was a scantyear ago. Although a gap still exists between computers and telephones, you nolonger need original research just to make, for example, a Screen pop appear ona call center PC. (For more information about what the industry was like in1996, see Alex Pournelle, "Computers and Telephones," Windows NTMagazine, June 1996.) To understand how this gap is closing so quickly, youneed to look at CT’s parent industries.

A Peek into the Past
The telephone industry’sevolution closely parallels that of the computer industry. First came themainframe era, in which AT&T provided all phone-related services, followedby the minicomputer era, in which the switch, or PBX, was key. In theminicomputer era, switch programmability was difficult at best and systems wereclosed to outsiders. As a result, if you wanted to bridge a call among threecircuits (e.g., a conference call) or needed a queue for an operator pool (e.g.,Automatic Call Distribution—ACD), you needed to install special switches orexpensive add-on boxes.

Then came early computer telephone integration. Solutions were proprietaryand difficult to implement, but they worked. Phone calls came right to acomputer, which routed them to a phone or another switch. Meanwhile, switchesand computers learned to communicate more effectively with each other, and PBXmanufacturers opened their systems to outside control (as long as you couldprogram in C).

Today, the CT industry closely resembles the PC industry. Traditionalproduct categories have blurred, with hardware and software coming from manysources. The net result of this banquet of choices is confusion, especially foroutsiders. At least when you bought a phone switch in the past, you knew whichvendors offered them. Now, numerous vendor offerings cross the previouslydefinite boundaries of "traditional" telephony products and services.

Sales channels have become confusing, too. At one time, telephonyconsultants were at arm’s length from both software and hardwaredevelopers; today, those same consultants might roll up their sleeves to punchdown the cable, install the system, and maintain it. Distribution channels havebecome similarly confused. You can now buy phone systems through traditionalcomputer sources and vice versa.

Despite the confusion, the CT industry has thrived, producing manyinnovations. These innovations fall into three categories: NT enhancements,applications and development tools, and hardware.

Windows NT: Now a Telephony Platform
Early CTsystems ran on IBM’s OS/2, Sun Microsystems' Solaris, Novell’sNetWare, or MS-DOS. Today, CT systems are hosted on Windows NT with TelephonyAPI (TAPI), NetWare with Telephony Services API (TSAPI), Solaris with JTAPI, orproprietary interfaces. The OS acts as an operator that directs and managescalls, sending commands through the API to the hardware. In such a setup, aMulti-Vendor Integration Protocol (MVIP), a Signal Computing System Architecture(SCSA), or another board-interconnect standard provides a mechanism forinterconnecting many CT resource ports inside a PC-based platform. Thisinterconnecting mechanism is one factor that differentiates CT solutions in asmall office/home office (SOHO) from those in an enterprise.

Another difference between SOHO and enterprise CT is the level of control.Because most SOHOs have only one phone, first-party call control (i.e., theability to control calls that come to your phone) is adequate. With first-partycall control, you can dial a number, transfer a call, or put a call on hold. Butbecause companies usually have numerous phones, they need third-party callcontrol (i.e., the ability to control a call not directly connected to yourcomputer). With third-party call control, a company’s computer cancontrol an entire phone system, making applications such as automated bankingservices possible.

NT 4.0 with TAPI 2.0 made third-party call control a reality. But byindustry standards, TAPI 2.0 is incomplete; enthusiasts have been waiting forthe release of TAPI 2.1, which finally hit public beta in May. TAPI 2.1 offersclient/server features for telephony control, a tightened standard, andimportant new features, such as Unicode support for internationalization, ActiveControl support, and a much better TAPI client manager. With TAPI 2.1,application-development tools and switch interfaces are smoother. (For moreinformation about TAPI and other standards in the CT industry, see the sidebar "TheRole of Standards in CT’s Growth".)

But the effectiveness of NT-based CT doesn’t depend only on how goodTAPI is. This fact was evident at Microsoft’s booth at the CT Expo.Microsoft ran demonstration applications on a Northern Telecom Meridian 1 phonesystem. The demonstration featured Screen pops containing information aboutcallers, ways to transfer calls, and techniques to control the phone system. AndMicrosoft’s demonstration barely scratched the surface of possible NT-basedCT applications. (For more information on these applications, see Chris Bajorekand Alex Pournelle, "The Marriage of Computers and Telephones," WindowsNT Magazine, September 1997.)

One nice benefit of attending an expo is seeing cutting-edge products.VenturCom’s Component Integrator (CI) definitely falls into that category.CI lets you embed NT or Windows CE on a no-hard-disk PC with realtimeextensions. As a development tool for integrating, configuring, and buildingdedicated NT target systems, CI extends NT into places previously held by onlyUNIX and MS-DOS and offers obvious appeal to the CT market.

After the CT Expo, Microsoft introduced a cutting-edge product of its own:Routing and Remote Access Service (RRAS) for Windows NT Server. RRAS, formerlycode-named Steelhead, is a networking software package that improves NT-basedCT. (For more information about RRAS, see Mark Minasi, "Steelhead Swimsinto the Mainstream," Windows NT Magazine, August 1997.) RRASconnects two or more locations over Internet links or dedicated links (e.g.,WAN). Because RRAS supports compressed and encrypted links, more MIS managersare likely to buy into the idea of using the Internet to haul their strategicpackets. (For more information about Microsoft’s link-state routingprotocol of TCI/IP networks, see Tao Zhou, "Steelhead’s OSPF Routing,"Windows NT Magazine, August 1997.)

CT Applications and Development Tools: The Fun Begins
The CT field used to be all development tools and no off-the-shelf software.Now, the field has expanded greatly, so you can pick and choose from manyproducts, ranging from complete SOHO software solutions to PBX front ends todevelopment systems.

Many off-the-shelf applications are now powerful enough to remove the needfor programming. For example, Active Voice’s PhoneMax is a SOHO solutionwith call control. Q.Sys’s CallProducer is an enterprise solution thatdisplays a company’s call information at a master station. It interfaces acompany’s existing phone system with its LAN and puts the front end onusers’ PCs. Applied Voice Technology’s CallXpressNT is a unifiedmessaging system for NT. It includes emails, calls, and faxes in one window.CallXpressNT will also read or fax email to you when you’re on the road.You can even remotely fetch faxes and forward them with voice annotation. (Formore products that can perform unified messaging and other applications, see the"Computer Telephony Buyer’s Guide,"

Naturally, complex solutions require a software development kit (SDK) andan advanced programmer to write the program. Many SDKs are Visual Basic(VB)-centric. You can write the program using the SDK libraries, which hide thecomplexity of the various functions (e.g., call control and voicerecord/playback). For example, Parity Software’s CallSuite uses VB, butalso supports Visual C++ and Delphi (which is appealing for enterprise-levelapplications). Parity Software’s TAPI Starter Bundle is a cheap way to getyour feet wet in CT and comes with a 700-page PC Telephony book.

Artisoft, famous for LANtastic, now sells Visual Voice, one of severalVB-centric application creators available. Visual Voice has a text-to-speechoption for playing back those "Your account balance is $17.31"messages from your bank. In addition, Visual Voice tracks call accounting (Who’scalling whom?) and call tracking (Who did this guy call in our office?)information, which can often help sell the application to the boss. A proversion for multiline call-processing boards is also available.

Some application creators use languages other than VB. For example, ExpertSystem’s Ease for Windows NT is an integrated development environment (IDE)that uses its own low-level language and hooks to C/C++ for completecustomization. With the IDE, you complete scenarios and provide triggers,actions, and data in a standard Windows framework. Ease for Windows NT has aruntime environment that sits on NT once you complete the installation.

Sometimes products cross category lines, such as Octel Communications'Unified Messenger. This product lets you retrieve voice mail messages from anyphone or computer and send voice email attachments. It’s both a traditionalcomputer program and a CT application. The idea of unified messaging and auniversal inbox is now becoming reality.

Like the PC industry, the CT industry is fractured. Some vendors providecall-processing cards, while others offer PBXs-on-a-card. Meanwhile, somecompanies sell complete systems. All solutions work, to varying degrees, witheither their application development tools or third-party tools. Industryleaders exist, but none dominates.

Although the structure of the CT and PC industries is similar, bigdifferences exist between traditional computing and CT applications. Onesignificant difference is the servers. CT applications run on big hardware. Theshow was full of CT servers right out of the industrial-computer world, completewith rack mounting, big fans, hot-swap disks, 10 to 20 slots, passivebackplanes, CPU and RAM on daughter cards, redundant power supplies, andtemperature alarms. Surprisingly, instead of seeing IBM, Compaq, AST, and otherwell-known PC names at the expo, I saw names such as Dolch, InterLogic, Ziatech,and Recortec. None of the big PC names makes enterprise-size CT servers, exceptDigital Equipment, which offers Alpha servers for that purpose.

Whoever the maker, the CT server usually has call-processing cards andfull-length ISA boards stuffed with analog components and digital signalprocessor (DSP) chips. Low-density cards, such as the 4-line Rhetorex RDSP/9432,have individual phone-line connections out the back of the board and some amountof onboard CPU. High-density boards, such as Dialogic’s D/240PCI-T1, mighttake an entire T-1 line worth of calls. No matter the cards’ density, alllisten for ringing, play a greeting, listen for touch-tone or rotary digits (orthe caller’s voice with the appropriate software), and then route the call.Some cards might then play another digitized message, offer text-to-speechconversion, or bridge conference calls.

In the world of CT servers, one rule holds true: the smarter the board, theless burden on the host CPU. The D/240PCI-T1, for instance, has three 66MHzMotorola DSP56002 DSPs and two Intel 486 GX CPUs for call processing. Obviously,for more smarts, you can expect to pay more money. (If you’re not using anSDK such as Visual Voice and CallSuite, you need to make sure that yourapplication-development software knows how to harness these smarts.)

The call-processing boards that I’m mentioning are but a tiny sampleof the available boards. Rhetorex, for instance, makes more than 20 boards.Dialogic offers more than 30, ranging from 1 line to 120 lines for ISA, PCI, andVMEbus. Some of these boards plug directly into a PBX. In addition, manyDialogic workalikes exist, such as NewVoice and Bicom. You must ensure theboards you select will support the software you want to install.

But you don’t need to build your system from components. If you want atotal solution, try an UnPBX, an NT-based phone system with automated attendant,voice messaging, ACD, and email functions. One exciting UnPBX approach, forexample, is Sphere Communications’ Sphericall software and hardwareproduct. Sphericall puts a switch in an NT Server. But it can also useasynchronous transfer mode (ATM) networking to combine LAN and voice traffic onthe same wires. You just need Sphere Communications’ PhoneNICs to connecteach phone to the host PC. The company also offers PhoneHubs to add plain oldtelephone service (POTS) phones without ATM. Most of the call handling is onScreen, so you don’t need expensive phones. (For more information aboutSphericall, see Chris Bajorek, "What’s Happening in ComputerTelephony," Windows NT Magazine, January 1997.) Sphericall blursthe line between computers and telephony. In fact, Sphericall received moreattention at NetWorld+InterOp than at CT Expo.

Despite all the board-level, UnPBX, and hybrid solutions, don’t expectthe traditional switch to dry up. Switches have redundancy and reliability thatmake PCs look like toy computers. (You can’t even put a card in a PCwithout turning it off.) In addition, many companies already have largeinvestments in switch equipment and telephones. So, instead of companiesreplacing their switch equipment, they will most likely use computers to moreeasily control the switches.

Predictions Through a Foggy Crystal Ball

Two events will affect CT in the near future. One event is the release of NT5.0. (For more information about the new NT 5.0 capabilities that will affectCT, see the sidebar, "Windows NT 5.0 and CT.") This new version of NTwill make CT applications, especially Internet-based ones, easier to develop—andthat brings us to the second event: the growing reliance on the Internet. Thewidespread popularity of the Internet will greatly affect both CT and NT.Companies will need to use both to help them meet their customers’ rapidlychanging needs. For example, companies will need to integrate Internetphone-like plugins into their customer service and tech support centers. Theywill also require page-push features to show customers the right Web page.Because more voice- and videoconferences will take place over the Internet,companies will need to install full-time (and large) connections. Companies willalso need telephone systems with an Ethernet jack so that they can make andreceive voice-over-IP calls directly. Finally, Internet delays will makeextranets to vital customers and suppliers more important.

In the more distant future, perhaps NT 6.0 will have more smarts for CT.But the independent CT application-development tools and CT hardware market aren’tgoing to fade away. Like dreams, both will change in unpredicTable and excitingways. Connecting and using all these new innovations will get easier for SOHOsand FORTUNE 500 organizations alike. I can’t wait for next year’s CTExpo show to see how.

The Role of Standards in CT’s Growth

Standards have been incredibly important to the CT industry’s growthand are shaping it today. Interoperability is one area in which standards play acritical role. Companies want to buy software and hardware components frommultiple vendors, install them on a Windows NT server, and have them all worktogether in call-automating harmony. For example, you can buy a voice card, faxcard, voicemail software, and fax server package from different vendors, andthrough the magic of standards, they peacefully coexist. They can even work asan integrated messaging solution with Microsoft Exchange Server and Outlook.

Vendors now have many standards to choose from. Open Database Connectivity(ODBC), SQL, Telephony API (TAPI), Telephony Services API (TSAPI), Messaging API(MAPI), H.323, S.x00, and Voice Profile for Internet Mail (VPIM) are but a few.(For more information on these standards, see Chris Bajorek and Alex Pournelle,"Computer Telephony Terms and Technologies," Windows NT Magazine,September 1997.)

In the last year, NT became a pivotal standard for CT, providing a commonsoftware platform for CT manufacturers. In fact, Microsoft has been a drivingforce in CT by providing the following standards:

•PC-based OS (MS-DOS, Windows 3.x, Windows 95, and NT)

•ODBC for database access

•Messaging API (MAPI) for messaging

•COM/DCOM for distributed object-oriented development

•Application development tools (primarily Visual C++ and Visual Basic)

•TAPI and related API standards

While Microsoft’s CT focus and momentum waned a bit during its fullfrontal attack on Netscape, the company recently updated its CT efforts withCOM-enabled TAPI 3.0. Microsoft has also been busy with an NT networkingstandard important to CT: RRAS (formerly code-named Steelhead) for NT Server.

When multiple corporate sites have their own CT systems, a natural needexists to network them. For example, if you want to send a voicemail message toa remote office, you need to send that message from your local system and havethe CT system automatically transfer it to the appropriate remote mailbox. WithRRAS, you can establish server-to-server connections that provide a conduit forthe routing of email, voice, fax, data, and video with equal ease andefficiency. Of course, you need application code to implement the routingfunction, but with NT making the network connections, CT application developershave one less piece that they must create themselves. The same update also makesit easier to create IP-to-PSTN gateways because establishing theserver-to-server connection is an intrinsic NT capability.

—Chris Bajorek

Windows NT 5.0 and CT
Core features in Windows NT 5.0 will spawn new computer telephony (CT)products and capabilities. Although NT 4.0 is already a highly capable CTplatform, NT 5.0 will make CT applications, especially Internet-based ones,easier to develop. Here are several new NT 5.0 capabilities that will affect CT.

Active Directory Service: The most strategic addition to NT5.0 will be the built-in Active Directory Service. It will enable manyuser-addressing features for communications routing, all of which NT willhandle. One such feature will let you publish controlled user information in aglobal directory entry. The global entry will let anyone on the Internet findyou.

Active Movie: New data-streaming protocols will simplifyimplementing Internet telephony applications. These protocols will, for example,make IP-to-Public Switched Telephone Network (PSTN) gateways easier to implementand appropriate for all realtime communications streams, including voice, fax,and video.

COM/DCOM support: NT 5.0 will offer support for ComponentObject Model/Distributed Component Object Model (COM/DCOM). Withthis support, NT can provide scalable object-oriented solutions.

Hot-swap: NT 5.0’s hot-swap feature will let usersexchange NT Server components without shutting down the server. This new featurewill most likely prompt PC vendors to begin supporting hot-swap capabilities,although they won’t address hot-swapping PCI cards.

Nonstop computing: On the software front, when Microsoftreleases the Wolfpack clustering program, more software and hardware companieswill use nonstop computing for failover in telephony. Thus, NT 5.0 users willhave nonstop computing capability.

Plug and Play (PnP) support: On the hardware front, NT 5.0’sPnP architecture will slowly make CT hardware easier to install compared withinstallation on those systems in which the call-processing boards have ISAarchitecture. But the switch to PCI will be slow until CT becomes moredo-it-yourself. In addition, PCI’s three to five cards-per-PCI-bus limitwill keep ISA from fading away for another year, at least for applicationsrequiring 8 to 10 boards. This situation will put CT in a separate box and outof the file server, especially in large installations (120 lines or more).

ReSerVation Protocol (RSVP): Microsoft will implement thisquality-of-service protocol for the Internet as part of NT 5.0. RSVP will enablerealtime communications that will be far less susceptible to dropouts.

Telephony API (TAPI) 3.0: This version of TAPI will mergecall control with media streaming and control. TAPI 3.0 will have features thatmake Internet telephony applications easier to implement. For example, a COMlayer will be put around TAPI 3.0, so developers can use their language ofchoice (e.g., Java, C++, or Visual Basic).

Virtual private networks: NT 5.0 will provide efficientserver-to-server routing over virtual private networks, providing low-cost CTbandwidth. No router hardware is necessary. These connections will providerealtime communications for all media types. (This capability is alreadyavailable for NT 4.0 through RRAS, which Microsoft released this summer.)

—Alex Pournelle and Chris Bajorek


Contact: Q.Sys • 513-745-8070Web: http://www.qsys.comEmail: [email protected]

CallSuite, TAPI Starter Bundle

Contact: Parity Software • 415-332-5656Web:

Component Integrator

Contact: VenturCom • 617-661-1230 or 800-334-8649Web: http://www.vci.comEmail: [email protected]


Contact: Dialogic • 973-993-3000 or 800-755-4444Web: http://www.dialogic.comEmail: [email protected]


Contact: Active Voice • 206-441-4700Web:


Contact: Rhetorex • 408-370-0881, Ext. 1Web: http://www.rhetorex.comEmail: [email protected]

Routing and Remote Access Service for Windows NT Server

Contact: Microsoft • 206-882-8080Web:

Unified Messenger

Contact: Octel Communications • 408-324-2000Web:

Visual Voice

Contact: Artisoft • 617-354 0600 or 800-914 9985Web: http://www.artisoft.comEmail: [email protected]

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