The present document sets out detailed and practical requirements for Duplex Universal Speech and Text (DUST) protocols and services that provide enhanced real time text and speech conversation for all users. The present document identifies existing textphones@ chat systems and protocols@ identifies user requirements for effective text and telephone conversation@ and gives methods of fulfilling these requirements. The present document identifies necessary extensions to signalling protocols and transport facilities of current multimedia systems to achieve the DUST requirements. In addition@ the present document sets out a migration process from existing national textphone systems. The present document points out where further standardization work is required to resolve any remaining problems. The present document contains information applicable to network operators@ service providers@ terminal and network manufacturers.