ITU-T Recommendations

This Recommendation defines the procedures used by Group 3 facsimile terminals as defined in ITU-T Rec. T.4. These procedures enable documents to be transmitted on the general switched telephone network, international leased circuits and the Integrated Services Digital Network (ISDN). Further, these procedures allow communication to be manual or automatic and for document transmission to be requested alternatively with telephone conversation. Amendment 1 specifies the extension of silence period when the fallback from V.34 fax to normal G3 fax happens in order that the fallback works well.