The DRS_MSG_QUERYSITESREPLYELEMENT_V1 structure defines the computed cost of communication between two sites.

 typedef struct {
   DWORD dwErrorCode;
   DWORD dwCost;
 } DRS_MSG_QUERYSITESREPLYELEMENT_V1;

dwErrorCode: 0 if this "from-to" computation was successful, or ERROR_DS_OBJ_NOT_FOUND if the "to" site does not exist.

dwCost: The communication cost between the "from" site and this "to" site, or 0xFFFFFFFF if the sites are not connected.