TIA TIA-678-B

Abstract

This standard is applicable to the interconnection of data terminal equipment (DTE) and data circuit-terminating equipment (DCE) employing serial binary data operation via the 100-series interchange circuits or data operation over equivalent logical circuits. <br>This standard specifies extensions to the protocol elements, procedures, and behaviors described in ANSI/TIA/EIA-602-1992 (TIA/EIA-602-A). These extensions are based on the "<strong>+</strong>" command prefix that is reserved by TIA/EIA-602-A for standardized extensions, and adhere to the extended command syntax conventions established by ITU-T V.250. <br>This standard generalizes the protocol elements, procedures, and behaviors described in TIA/EIA-602-A, making them applicable to DCE which operate over arbitrary data networks. <br>This standard defines the commands that the DTE may issue to: <br>(1) Interrogate the capabilities of the DCE, including determination of what data network types and associated network-specific AT command set extensions are supported by the DCE; <br>(2) Select among supported data network types for subsequent DCE processing of automatic calling and automatic call answering functions; and, <br>(3) Select among supported DTE-DCE interface protocols. <br>This standard defines the responses the DCE shall issue to those commands. Where possible, these commands and responses are taken from existing TIA standards. <br>This standard establishes required mappings between manufacturer-specific data network services and the DCE protocol elements, procedures, and behaviors referenced in TIA/EIA-602-A (e.g. ring, dial, answer, busy, on-line data state). <br>This standard establishes conventions for interworking of network-specific AT command sets in DCE which support multiple data network types. <br>This standard establishes a minimal DCE Common AT Command Set consisting of: <br>(1) Those commands defined in TIA/EIA-602-A and ITU-T V.250, and <br>(2) Required extensions using the +W command prefix in accordance with ITU-T V.250. <br>This standard establishes conventions for uniform extension of its own scope and content through Annexes. <br>Annex D defines optional extensions to the protocol elements, procedures and behaviors defined in the original standard, based on +WS and +WC command prefixes reserved for standardized extensions. The parameters in Annex D only affect operation of the DCE in Transparent Character Stream mode and in Reliable Transparent Character Stream mode, as selected by +WS45=0 or by +WS45=1.