Windows 9X Networking

WIndows 98 Telephony

TAPI Overview

TAPI is an interface that provides a method for applications to easily support telephone communications. Windows 95 shipped with TAPI 1.4, which provided support for the direct connection to a telephone network, automatic phone dialing, and interfaces for conference calling, voice mail, and caller id.

Windows 98 supports TAPI 2.1. In addition to being compatible with previously released versions of TAPI (including TAPI 2.0 in Windows NT 4.0), TAPI 2.1 gives developers additional extensions to easily create client-server telephony applications

TAPI 2.1 Architecture

When an 32-bit telephony application makes a TAPI call, Tapi32.dll passes it to the TAPI Server, Tapisrv.exe. The TAPI Server then communicates using the TAPI Service Provider Interface with the appropriate TAPI Service Provider (TSP).

The TAPI Service Provider is responsible for communicating with the telephone hardware to perform the application's request. Depending on the TAPI Service Provider, it may then use it’s own device drivers to communicate with the telephone hardware it supports. Unimodm.tsp is listed in the diagram as the TSP, however this could potentially be any TAPI Service Provider provided by a third party.

Note: Tapisrv.exe is now the core of TAPI. It runs as a separate process, assuming the role previously played in Windows 95 by Tapiexe and Tapi.dll.

New Telephony Control Panel Applet

Windows 98 includes a Telephony control panel applet from which users can adjust dialing properties and view installed TAPI service providers.

The first tab, My Locations, contains the information that was previously found in the Modems applets in Windows 95. This tab is still available from the modem control panel applet. Information regarding dialing location is entered here.

The Area Code Rules window allows for variances in calling area codes. Such variences include:

Areas where 10-digit dialing is required.
Areas where an area code covers both local calling as well as long distance calling.
Areas area codes share local calling areas.

Some areas (such as Seattle and New York City) have several area codes included in the local calling area. In such an area, you must dial the area code, and then the seven digit telephone number. The standard convention before this situation occurred was for an eleven digit dialing sequence, as the area code was for calling between local calling areas.

Such was a long distance call. Following this convention would have the ten-digit sequence preceded by a 1.

In areas where 10-digit dialing is required, the telephony sub-system must also be informed what area codes are local and which area codes are a out of the local calling area. It is simpler to identify one or the other, thus making both readily apparent by process of elimination.

The convention in Windows 98 is to identify those area codes that are inside the local calling area.

To set a different area code as a local call, click on the New button

New Area

The window depicted in will open. Input an area code into the textbox and then click OK. The area code that was entered into the textbox will appear in the list. Windows 98 will now treat calls to that area code as a local call and the prefix will appear in the list.

Long Distance Calls in a Single Area Code

Occasionally an area code covers such a large distance that calls with in are considered long distance, and then, although the call is within the area code the ten-digit number must be dialed, preceded with a 1. An example of this is the 512 area code. In such circumstances, it is necessary to set certain prefixes as long distance. The way this is done is to click on the New button.

New Long Distance Prefix Within an Area Code

The window shown will appear. Input the prefix into the Prefix textbox and click OK. The prefix will appear in the list and it will be treated as a long distance call.

To remove an item from the lists as depicted click on the item in the list and then click the remove button to the right of the respective list.

Calling Cards

If a calling card is used to make long distance calls then the procedure for performing such calls needs to be entered into Windows 98. The first thing that needs to be done is enable the option. This is done by clicking the checkbox. Placing a check in that checkbox will enable the calling card drop down menu depicted in the same figure. The most common cards we expect calls on that are supported out of the box are:

AT&T Direct Dial via 10ATT1
AT&T via 10ATT0
AT&T via 1-800-321-0288
MCI Direct Dial via 102221
MCI via 1-800-674-0700
MCI via 1-800-674-7000
MCI via 1-800-888-8000
US Sprint Direct Dial via 103331
US Sprint via 103330
US Sprint via 1-800-877-8000

Calling Card Configuration

These calling cards already have calling card sequences defined and thus need no further configuration. To configure a card, click the Calling Card button.

The Calling Card window will appear. This provides the ability to enter the Personal Identification Number for the calling card account and special numbers to use the card for long distance calls or international calls (often the same number for both).

Further, the exact sequence for placing an international or long distance call can be configured by clicking the appropriate button.

Calling Card Sequence

The same window is used for both long distance and international calls; the data however is kept separate. Up to six steps are supported for the sequence. The two parts of each step are action and input; the operating system performs an action and then waits for a pre-determined event.

The actions supported are:

Calling Card phone number
Destination Number [without area code]
Destination Number [including area code]
Destination Country/Region
PIN
Specified digits:
Done
Do Tone Dialing Hereafter
The inputs the operating system can wait for are:

Tone Done 2 Seconds 4 Seconds 6 Seconds 8 Seconds 10 Seconds

14 Seconds 18 Seconds 22 Seconds 28 Seconds 36 Seconds 46 Seconds

To set the dialing action or the input to wait for, use the drop down selectors.