In data communications, defined protocols which facilitates communication amongst a wide body of users. Early protocols merely provided for the interconnection of similar devices and the Arpanet was an exception which permitted the interconnection of any two devices. Some early protocols, e.g. BISYNC, became ad hoc standards since they were adopted by many other manufacturers. These are two international bodies concerned with standards CCITT and ISO. CCITT is responsible for standards in the field of public telecommunication services. It is a permanent committee of the ITU and its best known recommendations are the V and Xseries for analog and digital data transmission. ISO has a large number of member bodies, one or each participating country——BSI in the UK, ANSI in USA, AFNOR in France. Other bodies such as CCITT and ECMA are also represented. The European Conference of Post and Telecommunications Administrations undertake standardization in the field of telephony extending into other facilities provided by PTTs, e.g. digital data networks. National organizations such as the IEEE promulgate standards, e.g. RS 232, equivalent to CCITT V.24 and a local area network standard IEEE; 802.在數(shù)據(jù)通信中,為便于廣大用戶進(jìn)行通信而制定的規(guī)程。早期的規(guī)程是為相似的設(shè)備互 連而提出的,但Arpanet是個例外,它允許任何兩種設(shè)備進(jìn)行互連。有些早期的規(guī)程,如 BISYNC,因?yàn)橐褳樵S多廠家采用,成了事實(shí)上的標(biāo)準(zhǔn)。有兩個國際性組織即CCITT和ISO關(guān) 心這類標(biāo)準(zhǔn)。CCITT是國際電信聯(lián)盟ITU的常設(shè)委員會,負(fù)責(zé)公用電信服務(wù)領(lǐng)域中的標(biāo)準(zhǔn), 其中著名的是用于模擬傳輸?shù)腣系列推薦標(biāo)準(zhǔn)和數(shù)字?jǐn)?shù)據(jù)傳輸?shù)腦系列推薦標(biāo)準(zhǔn)。ISO擁 有大量成員團(tuán)體——每一個參加國,如英國是BSI,美國是ANSI,法國是AFNOR,其它社會團(tuán) 體如CCITT和ECMA也有代表參加。歐洲郵電管理部門會議決定把電話領(lǐng)域中標(biāo)準(zhǔn)化推廣 到PTT提供的其它設(shè)施,如數(shù)字?jǐn)?shù)據(jù)網(wǎng)。象IEEE美國學(xué)術(shù)機(jī)構(gòu)也頒布了標(biāo)準(zhǔn),即RS232,等 價于CCITT V.24及LAN標(biāo)準(zhǔn)IEEE 802。參閱ANSI,ARPA,BISYNC,CCITT，IEEE,IEEE 802, loca l area network, PTT, RS 232, V[·××]， X[·××]。