X.75¶

X.75 is an ITU standard originally developed for the Network-to-Network Interface (NNI) of X.25 networks.

A simplified (single-link) version of X.75 was used for transfer of asynchronous serial communication (like those usesd with traditional analog modems in the PSTN) via ISDN B-channels. This standard was mostly used in Europe, while in North America, V.120 was more frequently used.