The SESSION_HEADER structure contains information about a network session. This structure is pointed to by the ncb_buffer member of the NCB structure. SESSION_HEADER is followed by as many SESSION_BUFFER structures as are required to describe the current network sessions.
typedef struct _SESSION_HEADER { // sh
UCHAR sess_name;
UCHAR num_sess;
UCHAR rcv_dg_outstanding;
UCHAR rcv_any_outstanding;
} SESSION_HEADER;