ITU Q.521:1993
ITU Q.521:1993 Digital Exchange Functions
Table of Contents
1General2Exchangefunctionsfintroductionandframework
2.1General
2.2Exchangemodel
2.3Utilizationofexchangefunctionsforservices
3Generalfunctionsrequiredinanexchangefor
operationintheIDN,ISDNormixedanalogue/digital
environment
3.1Timingandsynchronization
3.2Signalling
3.3DataPacketHandling
3.4Informationretrievalandanalysis
3.5Resourcemanagement
3.6Ongoingoperations
4Functionsusedinprocessingbearerservicecall
attempts
4.1ProcessServiceRequest
4.2Connect(throughconnect)/Disconnect
4.3Performoriginatingscreening(inoriginating
exchange)
4.4Performterminatingscreening(interminating
exchange)
4.5ProcessAttempt
5AdditionalfunctionsrequiredtoprovideISDN
SupplementaryServices