The SESSION_RANK enumeration provides 4-byte signed integer values that describe whether the machine is a primary partner or a secondary partner.

 typedef  enum _SessionRank
 {
   SRANK_PRIMARY = 0x00000001,
   SRANK_SECONDARY = 0x00000002
 } SESSION_RANK;

SRANK_PRIMARY:  Primary partner.

SRANK_SECONDARY:  Secondary partner.