Telephony? Just Call on NT

Telemac creates debit cellular service

For many potential cellular phone customers, prepayment is the only way toget a mobile phone. Credit or income deficiencies will cause cellular serviceproviders to deny an estimated 28 million Americans a cellular phone by the year2000, according to Telemac's reports.

Developers at Telemac evaluated Windows NT as the platform for a newtelephony application to provide an innovative cellular service, debit phones,for customers with poor or no credit history. Debit phones let service providerstap into the credit-risk market and avoid bad debts. The programming team atTelemac, including brothers Chris and Greg McGregor, had used Unixware onprevious projects. "We had a long debate about Unix or NT for this newapplication," said Greg, Telemac's director of software planning. The teamconcluded that Unix's advantage was familiarity, and this appeal couldn't matchNT's available tools and support or lower development costs.

After deciding on NT, Telemac chose APEX Voice Communications's OmniVox forits interactive voice response unit (IVRU) system on the front end. ThenTelemac's development team decided that Raima's Velocis Database Server wouldmake its application a ringing success.

Problem and Solution
Telemac's new NT-based Debit Technology provides pay-as-you-go cellularservice. The debit phone has a chip that regulates the phone's available airtime. A back-end NT-based database server running NT 3.51 is at Telemac'sheadquarters in Danville, California. A customer calls in to an IVR system andenters a personal identification number (PIN). If the customer has a prepaidcalling card or a credit card Telemac's Debit Technology server applicationgives a code the customer keys into the phone to unlock more calling time.

Telephony is a key component of Telemac's solution. "We had to use theTelephony API (TAPI) to take advantage of the Remote Access Service (RAS)features in Windows 95 and NT," said Greg. "We use TAPI to communicateto cellular phones, process credit cards, and support the native dial-up serverunder NT and Win95."

Cutting Development Costs
Several key components of the Telemac's Debit Technology application wereless expensive for NT than for Unix. For voice processing, Telemac choseOmniVox, a high-level telephony application generator with a drag-and-drop,iconbased interface, and a Dialogic telephony card. Fully configured,OmniVox for Unix costs $8000, compared to $6400 for NT.

"We had one week to get the Debit Technology IVRU shell running,"Greg said. So Telemac called on Dialogic, a leading PC telephony voice cardmanufacturer, to recommend a telephony card and a voice processing developmentprogram. "Dialogic recommended OmniVox. OmniVox got us up and runningreliably and quickly," he said.

Performance wasn't a problem for Telemac's telephony application. "Withvoice stuff, the hardware, not the OS or application, does most of the work,"Greg said.

The cost of NT vs. Unix also affected decisions about the application'sserver side. Telemac liked the cost of NT Server, $699, compared to $1695 forUnixware. Only the back-end database server, Raima's Velocis Database Server,costs the same--$8995 for an unlimited client license--for NT and Unix when yourun Velocis on a low-end PC.

Choosing a Database Server
Telemac considered Microsoft's SQL Server and Raima's Velocis DatabaseServer for the back-end database server. SQL and Velocis offer similar features:Both are client/server databases, support SQL, include referential integrity andtransaction processing, and communicate with the OmniVox application through theMicrosoft Open Database Connectivity (ODBC) standard. But Velocis allows higherperformance by supporting multiple database architectures.

SQL Server follows the relational databases model. Velocis supportsrelational joins between records and lets you use network database architectureto connect records. This network architecture refers to a particular model forstoring and retrieving records. In this model, which predates relationaldatabases but is still a mainstay of some corporate data repositories, recordsjoin directly through pointers, so queries are much faster than with therelational model.

Developers also considered portability because Telemac expects somecustomers to buy the application and deploy it on Unix. Velocis ports easily tomost Unix variants, but SQL Server is NT-only.

A Winning Combination
Three major US cellular carriers recently completed testing Telemac's DebitTechnology, and it performed well. Telemac's Debit Technology runs on a Pentiumserver. As the application's use grows, Telemac will scale up to five Pentiumservers running NT and hosting the IVRU application, with a back-end Alpha NTdatabase server.

Telemac uses NT's Perfmon to tune the application and chose the NT FileSystem (NTFS) file structure over the File Allocation Table (FAT) structure. "NTFSoffers higher performance and better security than FAT," said John Dismuke,Telemac's director of MIS/communications, who oversees the daily operation ofTelemac's Debit Technology.

Telemac has joined NT's features with third-party tools to form a winningcombination. By choosing NT, Telemac and other application developers arerecognizing NT as a mature operating system.

Please see sidebar "An Interview with Telemac".