This article is from the Mac communications FAQ, by Bruce L Grubb BruceG6069@aol.com with numerous contributions by others.
Because these topics are universal telecommunications issues,
they are more fully discussed in comp.dcom.modems. However, a
short description of some of the more common abbreviations and
buzzwords is given below.
Buzzword What it typically means --------------- ---------------------------------------------- bit : binary digit; amount of information necessary to distinguish between two equally likely events (such as the value of a binary digit) byte : eight bits; size of a single ASCII character bps : bits per second baud : one analog signal state change; people usually use baud and bps interchangeable, although most modern modems can encode multiple bits per baud Bell 103 : 300 bps U.S. Standard Bell 212A : 1200 bps U.S. Standard LAP/M : Link Access Protocol/Modem. MNP : Microcom Networking Protocol (Proprietary) MNP5 : MNP extension; 2 to 1 data compression. V.32 : 9600bps, 4800bps V.32bis : 14.4Kbps, 12Kbps, 9600bps, 7200bps, 4800bps V.32terbo : psuedo-standard extending V.32bis to 16.8, 19.2 kbs V.34 : 28,800 bps, 14,400 bps, 9,600 bps, 2,400 bps V.Fast : Interim version of V.34; sometimes used as a nickname for V.34 V.FC : proprietary Rockwell protocol used before V.34 was approved as a standard V.42 : MNP 4 and LAP/M modem to modem error correction V.42bis : LAP/M and 4-to-1 data compression. V.44 : Internet focused compression X2/K56flex : Two incompatable proprietary formats for 56K Dependent on a digital equipment which some areas do not have. V.90 : base standard for 56K; 33,600 bps upload maximum V.92 : Improved 56K stadard; 48,000 bps upload maximum
FAX standards: V.21 : 300 bps FAX V.27ter : 4800 bps FAX V.29 : 9600 bps FAX V.17 : 14400 bps FAX