After exhaustive searching, I have been unable to find any standards for interworking ISDN supplementary services to SIP (Call Forwarding, Transfer, 3-Way calling, Call Waiting, Hold, etc. as described in Q.932 and the Q.730 series and Q.950 series docs as well as other docs covering NI-2, 5ESS variants, etc.). The closest I have found is Q.1912.5, but for supplementary services it refers to other Q.73x standards that basically say drop the feature indicator, i.e. don't interwork. I found reference to ETSI DEN/TISPAN-03012-NGN-R1 work item that covers DSS1-SIP interworking for ISDN basic call and supplementary services, but the status page shows the work item has been stopped, with the last deliverable being a draft in 2003 (that I can't find). The Rapporteur listed was Peter Kotar who also wrote draft-kotar-sipping-dss1-sip-iw-01 which expired in 2004 and notes supplemental services is out of scope of the document.
I've also looked around for off the shelf BRI-SIP gateways and none appear to support supplemental services. If anyone knows of gateways supporting supplementary services specifically for 5ESS, NI-2 and DMS-100 variants, or any standards covering this interworking I'd appreciate a pointer. John Hearty Voice Architect Level 3 Communications, LLC 1025 Eldorado Blvd Broomfield, CO 80021 720-888-2161 _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
