A gateway between a EUROCOM D/1-network and a private PTT-type CCITT SS7-network

The authors discuss the design of a digital gateway between a EUROCOM D/1 network and a private PTT-type CCITT SS7-network using eight TMS320C25 digital signal processors. This gateway converts 30 channel trunks between a tactical network and a fixed network. The gateway includes a signaling converter for EUROCOM D/1 loop signaling and CCITT SS7 TUP (telephone user part). The gateway also accomplishes speech transcoding between EUROCOM D/1 16 kb/s CVSD (continuously variable slope delta modulation) and 64 kb/s A-law pulse code modulation. The authors discuss possible methods for data conversion between EUROCOM D/1 RMVD/BCH-codes and PTT network, especially CCITT V.110/X.30 ISDN bit rate adaptation