The DCME Package is used for interfacing Digital Circuit Multiplication Equipment (DCME). DCME types are for instance defined by ITU-T Recs G.763 [b-ITU-T G.763], G.767 [b-ITU-T G.767] or G.768 [b-ITU-T G.768]. There is a signalling interface defined between DCME and asocalled "International Switching Centre" (ISC). ITU-T Rec. Q.50 [ITU-T Q.50] defines such an interface. The DCME Package scopes DCMEwith Q.50 interfaces (see Figure 1).