New Unimodem comm/datamodem device classes (323151)

SUMMARY

With Microsoft Windows 2000 and later versions of Windows, Unimodem separates the TAPI comm/datamodem device class into two separate device classes:

comm/datamodem/dialin
comm/datamodem/dialout

These new device classes can be used on any Unimodem device and in any API where a device class can be specified.

When used in the lineSetDevConfig function, each class sets the modem configuration for all telephone calls until the next call to the lineSetDevConfig function:

comm/datamodem/dialout for outbound calls
comm/datamodem/dialin for inbound calls

MORE INFORMATION

On versions of Windows earlier than Windows 2000, applications must configure TAPI modem devices for their own use, whether they make outbound or inbound calls. However, if one application, such as HyperTerminal, makes an outbound call while another application, such as remote access, waits for inbound calls, the outbound application might configure the device in a manner that is not compatible with the inbound application. The new device classes on Windows 2000 make this kind of conflict less likely.

Note These new device classes are not supported by any version of Unimodem earlier than Windows 2000. Also, they are not supported by many third-party technology solutions professionals. We recommend that applications first try either comm/datamodem/dialin or comm/datamodem/dialout. If these do not succeed, use comm/datamodem.

If an application uses comm/datamodem, this always uses comm/datamodem/dialout. However, this behavior is intended for earlier (legacy) applications. We recommend that developers use the new device classes to make their intentions clear.

REFERENCES

For more information about the lineSetDevConfig function, see the Microsoft Platform Software Development Kit documentation or visit the following Microsoft Developer Network (MSDN) Web site:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/tapi/tapi2/linesetdevconfig.asp