Digital Cross-Connect Systems CEPT Gateway Application

In order to provide digital telecommunication transport between Mexico and the United States, TELMAX and AT&T negotiated cross-border interconnection using the CEPT-1 facility format common throughout Mexico. Interworking between these 2.048-Mb/s facilities and the United States' DS-1 facilities (1.544 Mb/s) has been implemented in San Diego, California, El Paso, Laredo and Harlingen, Texas, using AT&T International DACS with CEPT enhancements. These CEPT gateway DACS: (1) cross-connect voice and data DS- O channels between the 30-channel CEPT-1 and the 24-channels DS-1 facility terminations; (2) convert DS-) channels between A-law and mu-law companding rules for PCM encoding; and (3) convert between CEPT's out-of-band 16-state channel- associated signaling and 4-state robbed bit signaling. These CEPT gateway DACS are integrated into the AT&T service node through interface with AT&T operations support systems that serve the operations and maintenance functions of: (1) facility provisioning, performance monitoring, and testing; (2) circuit provisioning and testing; and (3) DACS memory backup and remote DACS equipment maintenance.