2.2.3.1.44 LINEMEDIAMODE_Constants

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The LINEMEDIAMODE_Constants are bit-flag constants that describe media types (or modes) of a communications session or call.

Constant/value

Description

LINEMEDIAMODE_UNKNOWN

0x00000002

A media stream exists but its mode is not currently known and can become known later. This condition would correspond to a call with an unclassified media type. In typical analog telephony environments, the media type of an incoming call can be unknown until after the call has been answered and the media stream has been filtered to make a determination.

If the unknown media-mode flag is set, other media flags can also be set. This flag is used to signify that the media is unknown but that it is likely to be one of the other selected media types.

LINEMEDIAMODE_INTERACTIVEVOICE

0x00000004

Voice energy was detected on the call, and the call is handled as an interactive voice call with humans on both ends.

LINEMEDIAMODE_AUTOMATEDVOICE

0x00000008

Voice energy was detected on the call, and the voice is locally handled by an automated application, such as with an answering machine application. When a service provider cannot distinguish between interactive and automated voice on an incoming call, it will report the call as interactive voice.

LINEMEDIAMODE_DATAMODEM

0x00000010

A data modem session on the call. Current modem protocols require the called station to initiate the handshake. For an incoming data modem call, the application can typically make no positive detection. How the service provider makes this determination is its choice. For example, a period of silence just after answering an incoming call can be used as a heuristic to decide that this call might be a data modem call.

LINEMEDIAMODE_G3FAX

0x00000020

A group 3 fax is being sent or received over the call.

LINEMEDIAMODE_TDD

0x00000040

A Telephony Devices for the Deaf (TDD) session on the call.

LINEMEDIAMODE_G4FAX

0x00000080

A group 4 fax is being sent or received over the call.

LINEMEDIAMODE_DIGITALDATA

0x00000100

A digital data stream of unspecified format.

LINEMEDIAMODE_TELETEX

0x00000200

A teletex session on the call. Teletex is one of the telematic services.

LINEMEDIAMODE_VIDEOTEX

0x00000400

A videotex session on the call. Videotex is one the telematic services.

LINEMEDIAMODE_TELEX

0x00000800

A telex session on the call. Telex is one of the telematic services.

LINEMEDIAMODE_MIXED

0x00001000

A mixed session on the call. Mixed is one of the ISDN telematic services.

LINEMEDIAMODE_ADSI

0x00002000

An ADSI session on the call. ADSI enhances voice calls with alphanumeric information that is downloaded to the phone and with the use of soft buttons on the phone.

The following constants are present in TAPI versions 1.4, 2.0, 2.1, 2.2, 3.0, and 3.1.

Constant/value

Description

LINEMEDIAMODE_VOICEVIEW

0x00004000

The media type of the call must be VoiceView.

The following constants are present in TAPI versions 2.1, 2.2, 3.0, and 3.1.

Constant/value

Description

LINEMEDIAMODE_VIDEO

0x00008000

The media type of the call must be video.

Note that bearer mode and media type are different notions. The bearer mode of a call is an indication of the quality of the telephone connection, as provided primarily by the network. The media type of a call is an indication of the type of information stream that is exchanged over that call. Group 3 fax or data modem are media types that use a call with a 3.1-kHz voice bearer mode.

For backward compatibility, it is the responsibility of the service provider to examine the negotiated TAPI version on the line and to not use this LINEMEDIAMODE_Constants value if it is not supported on the negotiated version.