2.2.3.1.15 LINEBEARERMODE_Constants
The LINEBEARERMODE_Constants are bit-flag constants that describe the different bearer modes of a call. When a call is made, it can request a specific bearer mode. These modes are used to select a certain quality of service for the requested connection from the underlying telephone network. Bearer modes that are available on a particular line are a device capability of the line.
|
Constant/value |
Description |
|---|---|
|
LINEBEARERMODE_VOICE 0x00000001 |
A regular 3.1-kilohertz (kHz) analog voice-grade bearer service. Bit integrity must not be assured. Voice-grade bearer service can support fax and modem media types. |
|
LINEBEARERMODE_SPEECH 0x00000002 |
The LINEBEARERMODE_SPEECH corresponds to G.711 speech transmission on the call. The network can use processing techniques such as analog transmission, echo cancellation, and compression/decompression. Bit integrity must not be assured. Speech must not be intended to support fax and modem media types. |
|
LINEBEARERMODE_MULTIUSE 0x00000004 |
The multiuse mode that is defined by ISDN for the call. |
|
LINEBEARERMODE_DATA 0x00000008 |
This flag allows for the unrestricted data transfer on the call. The data rate must be specified separately. |
|
LINEBEARERMODE_ALTSPEECHDATA 0x00000010 |
This flag allows for the alternate transfer of speech or unrestricted data on the same ISDN call. |
|
LINEBEARERMODE_NONCALLSIGNALING 0x00000020 |
This capability corresponds to a non-call-associated signaling connection from the application to the service provider or switch (treated as a media stream by TAPI). |
The following constants are present in TAPI versions 1.4, 2.0, 2.1, 2.2, 3.0, and 3.1.
|
Constant/value |
Description |
|---|---|
|
LINEBEARERMODE_PASSTHROUGH 0x00000040 |
When a call is active in LINEBEARERMODE_PASSTHROUGH mode, the service provider gives direct access to the attached hardware for control by the application. This mode must be used primarily by applications that want temporary direct control over asynchronous modems, accessed through the communications functions, for the purpose of configuring or using special features that are not otherwise supported by the service provider. |
The following constants are present in TAPI versions 2.0, 2.1, 2.2, 3.0, and 3.1.
|
Constant/value |
Description |
|---|---|
|
LINEBEARERMODE_RESTRICTEDDATA 0x00000080 |
Bearer service for digital data in which only the low-order 7 bits of each octet can contain user data (for example, for switched 56-kbps service). |
The high-order 16 bits can be assigned for device-specific extensions. The low-order 16 bits are reserved.
Note that bearer mode and media type are different notions. The bearer mode of a call MUST be an indication of the quality of the telephone connection as provided primarily by the network. The media type of a call MUST be 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.