| Constant | Meaning | 
   
    | LINEBEARERMODE_VOICE | This is a regular 3.1 kHz analog voice-grade bearer service. Bit integrity 
        is not assured. Voice can support fax and modem media types.  | 
   
    | LINEBEARERMODE_SPEECH | This 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 is not assured. Speech is 
        not intended to support fax and modem media types. | 
   
    | LINEBEARERMODE_MULTIUSE | The multiuse mode defined by ISDN.  | 
   
    | LINEBEARERMODE_DATA | The unrestricted data transfer on the call. The data rate is specified 
        separately.  | 
   
    | LINEBEARERMODE_ALTSPEECHDATA | The alternate transfer of speech or unrestricted data on the same call 
        (ISDN).  | 
   
    | LINEBEARERMODE_NONCALLSIGNALING | This corresponds to a non-call-associated signaling connection from the 
        application to the service provider or switch (treated as a media stream 
        by TAPI). | 
   
    | LINEBEARERMODE_PASSTHROUGH | When a call is active in LINEBEARERMODE_PASSTHROUGH, the service provider 
        gives direct access to the attached hardware for control by the application. 
        This mode is used primarily by applications desiring temporary direct 
        control over asynchronous modems, accessed through the Win32 comm functions, 
        for the purpose of configuring or using special features not otherwise 
        supported by the service provider. | 
   
    | LINEBEARERMODE_RESTRICTEDDATA | Bearer service for digital data in which only the low-order seven bits 
        of each octet may contain user data (for example, for Switched 56kbit/s 
        service).  |