All CODAN modems can send data either by a peer-to-peer or by a broadcast communication. The modes CODAN-9001 and CODAN-3012 use the same coding, modulation, scrambling and transmission modes (secure, secure interactive and unsecure). The only difference is that a fax device can be additionally connected to a CODAN-9001 modem. CODAN-3212, which is the successor of CODAN-3012, has the possibility to communicate with other CODAN-3012 modems by using the CODAN-3212 compatibility mode. The CODAN-3212 compatibility mode uses a different preamble from the modes CODAN-9001 and CODAN-3012 for synchronisation. The coding, modulation, scrambling and the transmission modes (secure, secure interactive and unsecure) remain the same.