H-NET H-NET H-NET H-NET H-NET H-NET H-NET H N N E ** H-Net Magazine ** E T T H Volume One, Issue 1, File #11 of 20 H N N E CCITT Recommendations by Zed Haytey. E T T H-NET H-NET H-NET H-NET H-NET H-NET H-NET H CCITT RECOMENDATIONS V series - covering data transmissions over telephone lines V1 Equivalence between binary notation stmbols and the significant cond- itions of a two conditioned code V2 Power levels for data transmission over telephone lines V3 International Alphabet No.5 (ASCII) V4 General structure of signals of International Alphabet No.5 code for data transmissions over public telephone networks V5 Standardisation of modulation rates and data signalling rates for synchronoous data transmission in general switched network V6 Ditto, on leased telephone type circuits V7-9 Not assigned V10 Electrical characteristics for unbalanced double current interchange circuits for general use with integrated circuits V11 Ditto, for balanced double current interchange circuits V12 Not assigned V13 Answerback simulator V14 Not assigned V15 Use of acoustic coupling for data transmission V16 Recommendation for modems for transmission of medical analogue data V19 Modems for parallel data transmissions using telephone signalling frequencies V20 Parallel data transmission modems standardised for universal use in the general switched network V21 300 Baud modem standardised for use in the switched telephone network V22 1200 Baud full duplex 2 wire modem standardised for use in the general switched telephone network V22b 2400 Baud full duplex 2 wire modem standardised for use in the general switched telephone network V23 600/1200 baud modem standardised for use in the general switched telephone network V24 List of definitions for interchange circuits between data terminal equipment and data circuit terminating equipment (i.e. modem) V25 Automatic calling and/or answering equipment on the general switched telephone network V25b Bit synchronous auto dialling protocol for use over PSTN V26 2400 baud modem for use on 4 wire point to point circuits V26b 2400/1200 baud modem standardised for use in the general switched telephone network V27 4800 baud modem for leased circuits V27b 4800/2400 modem with automatic adaptive equaliser standardised for use on leased circuits V27t 4800/2400 modem standardised for use on the general switched telephone network V28 Electrical characteristics for unbalanced double current interchange circuits V29 9600 baud modem for use on leased circuits V30 Not assigned V31 Electrical characteristics for single current interchange circuits controlled by contact closure V32-4Not Assigned V35 Data transmission at 48 kilobits per second using 60-108KHz group band circuits V36 Modems for synchronous data transmission using 60-108kHz group band circuits V37-9Not assigned V40 Error indication with electromechanical equipment V41 Code independent error correction system V42-9Not assigned V50 Standard limits for transmission quality of data transmission V51 Organisation of the maintenance of international telephone type circuits for data transmission V52 Characteristics of distortion and error rate measuring apparatus for data transmission V53 Limits for the maintenance of telephone type circuits used for data transmissions V54 Loop test device for modems V55 Specification for an impulsive noise measuring instrument for telephone type circuits V56 Comparative test for modems for use over telephone type circuits V57 Comprehensive test set for high signalling rates. by Zed Haytey 1990 =============================================================================== [Hackernet BBS,LEEDS,UK(0532)557739, 24hrs. Home of H-Net Hacking magazine]