This Recommendation provides network Grade of Service (GOS) parameters for circuit-switched services in ISDN, based on the ISDN Grade of Service concept and guidelines for selecting GOS parameters provided in Recommendation E.720. The parameter values assume that the network and the components are fully operational and take account of the evolving nature of the ISDN and Signalling System No. 7 capabilities.
ITU-T E.721 FRENCH-1999 Referenced Document
ITU-T E.172-1992 ISDN Routing Plan - Telephone Network and ISDN; Operation Numbering Routing and Mobile Service (Study Group II) 21 pp
ITU-T G.101-1996 Transmission Plan - Series G: Transmission Systems and Media International Telephone Connections and Circuits - General Definitions (Study Group 12)
ITU-T I.350-1993 General Aspects of Quality of Service and Network Performance in Digital Networks Including ISDNs Study Group XVIII
ITU-T I.352-1993 Network Performance Objectives for Connection Processing Delays in an ISDN (Study Group XVIII) 22 pp
ITU-T Q.543-1993 Digital Exchange Performance Design Objectives (Study Group XI) 39 pp
ITU-T Q.706-1993 Signalling System No. 7 - Message Transfer Part Signalling Performance
ITU-T Q.709-1993 Signalling System No. 7 - Hypothetical Signalling Reference Connection - Specifications of Signalling System No. 7 (Study Group XI) 17 pp
ITU-T Q.766-1993 Performance Objectives in the Integrated Services Digital Network Application - Specifications of Signalling System No. 7 ISDN User Part (Study Group XI) 7 pp
ITU-T Q.921-1997 ISDN user-network interface Data link layer specification Study Group 11; 269 pp
ITU-T Q.931-1998 ISDN user-network interface layer 3 specification for basic call control Study Group 11
ITU-T E.721 FRENCH-1999 history
1999ITU-T E.721 FRENCH-1999 Network grade of service parameters and target values for circuit-switched services in the evolving ISDN Study Group 2; 11 pp