The Recommendation describes that the second order digital multiplex equipment using positive justification described below, is intended for use on digital paths between countries using 1544 kbit/s primary multiplex equipments.
ITU-T G.743 SPANISH-1993 history
1993ITU-T G.743 SPANISH-1993 SECOND ORDER DIGITAL MULTIPLEX EQUIPMENT OPERATING AT 6312 kbit/s AND USING POSITIVE JUSTIFICATION