This section defines basic PC 98 hardware feature requirements for modems.
2. Modem supports TIA-602 Hayes-compatible command set
Required
TIA-602 codifies the most common data modem. As part of the command set, the modem must have a distinct means for controlling the reporting of modem-to-modem protocols, so the modem can be forced to generate recognizable reports for modulation, error control, and data compression. Examples include the Wn command, the S95 register, the \Vn command, and the ITU V.25ter +MR, +ER, and +DR commands.
Recommended: ITU V.25ter, which is a superset of TIA-602 with significant and useful improvements. It includes three new components:
The particular utility of the standard format is that it allows a future modem installer to adaptively install and use a modem, with minimal need for INF file minidrivers. This will be provided in versions of the MDK available in the second half of 1997.
3. Data modem supports 33.6 Kbps (V.34-1996) with V.42 and V.42bis protocol
| Required |
This is the minimum modem capability specified for PC 98.
4. Data modem supporting speeds faster than 33.6 Kbps can be upgraded to V.pcm
Required
Any modem that supports speeds faster than 33.6 Kbps must be capable of being upgraded to V.pcm. For Entertainment PC 98 systems, any modem supplied with the system must have this capability.
See the related “PCM modem supports ITU-T V.pcm” requirement later in this chapter.
5. Fax modem supports 14.4 Kbps (V.17) with Class 1 (TIA-578-A) command set
Required
The following are recommended:
Windows is bundled with fax-modem support. Windows NT 5.0 and future versions of Microsoft BackOffice® products will support Class 1.0 and Class 2.0 fax modems and use adaptive call-classification support. To benefit from this support, modem vendors should extend their modem INF files to support the new registry keys that are needed to support these features, as defined in the MDK available in the last quarter of 1997.
6. Data modem supports V. 80 for synchronous access
| Recommended |
This standard provides a control plane for the modem and synchronous access to the data path, the foundation for third-party voice/data/video software (for example, H.324, V.70). Modems that support V.80 should also include V.8bis signaling and V.25ter Annex A as described in the following item.
7. Modem supports adaptive connection, V.25, V.8, and V.8bis call control signaling with V.25ter Annex A modem commands
Recommended
V.25 defines basic call-type selection, with an answer tone, a fax-calling tone, and a data-calling tone. V.8 defines advanced call-type selection, with complex information exchanged between terminals; V.8 is used in V.34, V.pcm, and some digital simultaneous voice/data (DSVD) implementations. V.8bis is required for the following standard multimedia modes: V.61 ASVD, V.70 DSVD, and H.324 video telephony.
V.25ter Annex A enables the PC to participate in call control, allowing flexibility and a visual user interface as well as saving modem complexity.
8. Modem supports delayed and blacklisted number clearing
Recommended
The modem should clear its delayed and blacklisted number tables if the associated handset goes off hook.
During certain international PTT certification processes, modems must support the delayed and blacklisted numbers feature. That means that when the modem fails to connect to a specific number for a certain number of times, the dialed number is stored in an internal list. Any subsequent automated dialing operation to this number is then either delayed for a time (delayed) or might be forbidden until some form of manual intervention occurs (blacklisted). The international certification processes specify that manual intervention using an external device is required in order to clear these numbers.
Windows will provide error messages corresponding to delayed and blacklisted error reports in order to reduce customer confusion.
9. Modem supports TDD, meeting V.18-1996 with V.25ter AT commands
Recommended
People with deafness or reduced hearing can use Telephone Device for the Deaf (TDD), also known as Text Telephones, to communicate over phone lines. The U.S. Americans with Disabilities Act (ADA) requires all businesses of a certain size or larger to have Text Telephone services available and to be able to receive calls from people using Text Telephones.
In North America and Europe, the following types of Text Telephones are used:
ITU recommendation V.18 codifies how all these devices work and how to adaptively connect to all of them. ITU recommendation V.25ter contains AT commands for control of V.18 features in a modem.
It is recommended to include Text Telephone capability for the type commonly used in the country of sale and use (for example, Baudot in the United States, Minitel in France, and so on).
10. PCM modem supports ITU-T V.pcm
| Required |
For PCM modems (faster than V.34-1996), ITU V.pcm is a requirement. Compliance testing for this requirement will begin within a reasonable time frame after ITU V.pcm is approved by ITU Study Group 16 (currently projected for January 1998). If V.pcm has not been approved by the time PC 98 compliance testing begins, the modem must be end-user upgradable by software means to the current version of V.pcm. It is critical not to strand end users with devices that must be replaced later.
11. Modem controller meets PC 98 requirements
Required
The following are PC 98 requirements for the modem controller:
The following are PC 98 recommendations for the modem controller: