ISO/IEC INTERNATIONAL STANDARD 8481 Secondedition 1996-06-15 Information technology Telecommunications and information exchange between systems DTE to DTE direct connections Technologies de I'information - Télécommunications et échange d'information entre systemes -Connexions directes de DTE a DTE IEC Reference number ISO/IEC 8481:1996(E) Copyright Intermational Organization for Standardization rovided by IHS rmitted without license from IHS Not for Resale ISO/IEC8481:1996(E) Foreword ISO (the International Organization for Standardization) and IEC (the Inter- national Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of iSO or IEC participate in the development of International Standards through technical lar fields of technical activity. ISO and IEC technical committees collab- orate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology. ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. International Standard ISO/IEC 8481 was prepared by Joint Technical Committee ISO/lEC JTC 1,Information technology, Telecommunications and information exchangebetween systems. This second edition cancels and replaces the first edition (ISO 8481:1986) which has been technically revised. Annex A of this International Standard is for information only. @ ISO/IEC1996 photocopying and microfilm, without permission in writing from the publisher. 1SO/IEC Copyright Office · Case postale 56 · CH-1211 Geneve 20 · Switzerland Printed in Switzerland ii CopyrightIntemational Organizatin for Standardization ed without license from IHS Not for Resale ISO/EC8481:1996(E) @ ISO/IEC Introduction This Intemational Standard provides for the interconnection of Data Terminal Equipment (DTE) without any signal conversion, whereby a DTE is not The desired DTE to DTE direct connection may be totally located at the users premises. The aim is to relate these interconnections to the elements of The normative part of this standard provides for interconnection for both asynchronous and synchronous transmission, using CCITT Recommendation X.24 interchange circuits, including circuit X for synchronous transmission, and using ITU-T Recommendation V.11 electrical characteristics. An informative annex provides guidance for other cases of interconnection that, though acceptable under limited conditions, cannot be both DTEs with ITU-T Recommendation V.11 electrical characteristics. transmited signal is such that no general method of interconnection can be recommended. ili Copyright Intemational Organization for Standardization No reproduc permitted without license from IHS Not for Resale