DSVD terminals provide communication of real-time audio and data information using ITU-T V-Series modems over the GSTN. This Recommendation specifies control procedures to establish a point-to-point DSVD connection. The procedures described within this Recommendation can be incorporated, for example, by a Multipoint Control Unit (MCU), to support a multipoint DSVD terminal conference. The procedures described within this Recommendation specifj the manner in which DSVD terminals with different connection capability sets exchange media and data link capability information so that a common mode of communication can be established. Procedures are defined for exchange of capabilities at the beginning of a DSVD connection and while a DSVD connection is in progress. Establishing the physical connection (call control) is outside the scope of this Recommendation and is described elsewhere. DSVD terminals are made aware of a remote terminal's support of DSVD capabilities prior to a DSVD session using the procedures described in Recommendation V.8 bis [2]. DSVD specifies the use of two types of media streams - data and audio. Data and audio streams are multiplexed onto one physical connection using LAP-based multiplexing as defined in Recommendation V.76 [7]. Optional procedures are described within this Recommendation to support the exchange of connection capabilities that are independent of a media stream.