ITU I.221:1993
ITU I.221:1993 Common Specific Characteristics Of Services
Table of Contents
1ScopeandcontentoftheRecommendation2Commonspecificcharacteristics
2.1DefinitionofbusyinanISDN
AnnexAHandlingofactiveandheldcalls
A.1Introduction
A.2Functionalityavailabletotheserveduser
controllingmorethanonecall