ISDN Protocol Administrator's and Developer's Guide ... - Intervoice

E1 Transfer MethodsQSIG Path-Replacement TransferFor more information onITU-T standard Q.931,see the ITU-T documentList of ITU-TRecommendations.For more information onany of the ETSI standardsmentioned here, see“ETSI” on page xxx fordocument specifics.For more information onQSIG, refer to “QSIGProtocol,” Chapter 5.QSIG is a type of ISDN that is based on the ITU-T Q.931 standard. Ituses ROSE encoding and object identifiers for its varioussupplementary services. While the identifiers can be coded fromstandards produced by ISO, ECMA, or ETSI, the Intervoiceimplementation uses ETSI standards.The call control is defined in ETSI specifications EN 300 171 and EN300 172. The switch type is defined in the configuration file, sincevarious switch vendors may vary in their methods of implementation.The Path-replacement type of call transfer is defined in ETSIspecifications ETS 300 258 and ETS 300 259. Path replacement is asupplemental service that uses two lines, a primary line and an outboundline.Once a switch has accepted the transfer request, both calls are connectedat the switch and the Omvia Media Server releases both B channels.The characteristics of Path-replacement call transfer are shown inTable 3-8.Table 3-8. Path-Replacement Call Transfer CharacteristicsSpan Type Transfer Type connect UserDLL?E1 Two Line Transfer Yes60001262, First Edition Call Transfer 3-9