ISDNLINECAPS

The ISDN device's physical line capabilities are enumerated in the ISDNLINECAPS structure.

typedef struct tagISDNLINECAPS {
   DWORD   cbSize;          /* size of entire structure */
   DWORD   dwFlags;         /* flags for the line (ISDN_LINE_*) */
   DWORD   dwChannelFlags;  /* flags for the channels (ISDN_CHAN_*) */
   DWORD   dwSwitchType;    /* switches supported */
   DWORD   dwSpeedType;     /* speed type */
   DWORD   cChannelsMax;    /* number of B-channels per line supported */
   DWORD   cActiveChannels; /* number of active channels */
   } ISDNLINECAPS, FAR * LPISDNLINECAPS;

The field descriptions follow:

cbSize	The size of the entire ISDNLINECAPS structure.
dwFlags	Line capability options. This is a bit field, where the possible flags are: `ISDN_LINE_DEFAULT Default settings ISDN_LINE_INACTIVE The line can be inactive`
dwChannelFlags	Channel capability options. This is a bit field, where the possible flags are: `ISDN_CHAN_DEFAULT Default settings ISDN_CHAN_INACTIVE The channel can be inactive ISDN_CHAN_SPEED_ADJUST Connection speed can adjust downwards`
dwSwitchType	Refers to the switch types that this line supports. This is a bit field, where any or all of the following flags may be set. `ISDN_SWITCH_NONE No switch ISDN_SWITCH_AUTO Automatic ISDN_SWITCH_ATT AT&T ESS 5 ISDN_SWITCH_NI1 National ISDN 1 ISDN_SWITCH_NTI Northern Telecom DMS 100 ISDN_SWITCH_INS64 NT&T (Japan) ISDN_SWITCH_1TR6 Deutsche Telecom ISDN_SWITCH_VN3 French Telecom ISDN_SWITCH_NET3 European Switch ISDN_SWITCH_AUS Australian Switch ISDN_SWITCH_BEL Belgium Switch`
dwSpeedType	Refers to the speed and data types that the channels on this line support. This is a bit field, where any or all of the following flags may be set. `ISDN_SPEED_56K_VOICE 56kbps voice ISDN_SPEED_56K_DATA 56kbps data ISDN_SPEED_64K_DATA 64kbps data ISDN_SPEED_128K_DATA 128kbps data`
cChannelsMax	Refers to the number of B-channels the physical line has. This field must match the number of ChannelY keys that are in the line registry key of the driver.
cActiveChannels	Refers to the number of B-channels that are active on the line. This value is derived from the number of ChannelY keys that have the ISDN_CHAN_INACTIVE bit set in their Properties value. This value is determined at run time and should be set to zero in an INF.