Purpose
 Used by the x25_call_clear and x25_receive  subroutines to pass the
clear cause and diagnostic values, called and calling addresses, 
facilities information, and user data.
Syntax
 #define X25FLG_CAUSE        ;0x00000001
#define X25FLG_DIAGNOSTIC   0x00000002
#define X25FLG_CALLED_ADDR  0x00000004
#define X25FLG_CALLING_ADDR 0x00000008
#define X25FLG_CB_FAC       0x00000010
#define X25FLG_USER_DATA    0x00000020
struct cb_clear_struct
{
  unsigned long flags;
  u_char cause;
  u_char diagnostic;
  char *called_addr;
  char *calling_addr;
  struct cb_fac_struct *cb_fac;
  int user_data_len;
  u_char *user_data;
};
Flags
 | Item | Description | 
|---|
| X25_FLG_CAUSE | Indicates that the cause field is used. | 
| X25_FLG_DIAGNOSTIC | Indicates that the diagnostic field is used. | 
| X25_FLG_CALLED_ADDR | Indicates that the called_addr field is used. | 
| X25_FLG_CALLING_ADDR | Indicates that the calling_addr field is used. | 
| X25_FLG_CB_FAC | Indicates that the cb_fac field is used. | 
| X25_FLG_USER_DATA | Indicates that the user_data field is used. | 
Fields
 | Item | Description | 
|---|
| flags | Notification to the API that the associated field has been
used. | 
| cause | Cause value to be inserted in clear packet. | 
| diagnostic | Diagnostic reason to be inserted in packet. | 
| called_addr | Pointer to the network user address (NUA) of the called data
terminal equipment  (DTE). The address is given in ASCIIZ format. | 
| calling_addr | Pointer to the NUA of the calling DTE. The address is given
in ASCIIZ format. | 
| cb_fac | Pointer to the facilities information in the cb_fac_struct structure. | 
| user_data_len | Length of user-data field. | 
| user_data | Pointer to user data. This can be used only if "fast select"
has been requested in  the call-request packet. |