ANSI/NEMA C12.21-2006

Details the criteria required for communications between a C12.21 device and a C12.21 client via a modem connected to the switched telephone network. The C12.21 client could be a laptop or portable computer, a master station system or some other electronic communications device.

This product replaces:ANSI C12.21-1999 - Protocol Specification for Telephone Modem Communication
This product is included inANSI/NEMA C12 Series - Protocol Specification for Telephone Modem Communication