Long deprecated standard for a modem that survived only in the form of a connector, the shape and pinout of which were defined for the modem. The V.35 connector is big, bulky, and slow by today's standards.
An ITU standard (1968) for group band analog modems that combines the bandwidth of several telephone circuits to achieve higher data rates. Although not specified in the ITU standard, the V.35 connector has become a de facto standard for a serial interface in the 48 to 64 Kbps range. It is typically used between a modem and a multiplexor.