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MIME media types for DPNSS Objects in SIP { draft-mukundan-sipping-dpnss-02.txt : R Mukundan, V Seshasayee / K Morneault / R Shiroor / N Mangalpally / S Naganathan Wipro / Cisco/ Sasken / Nortel / Hughes } . Ranjith Mukundan Wipro Technologies. B. B. A. A.
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MIME media types for DPNSS Objects in SIP{draft-mukundan-sipping-dpnss-02.txt :R Mukundan, V Seshasayee/ K Morneault/ R Shiroor/ N Mangalpally/ S NaganathanWipro/ Cisco/ Sasken/ Nortel/ Hughes} Ranjith Mukundan Wipro Technologies
B B A A What is DPNSS (in 30 secs)?? • DPNSS == Digital Private Network Signaling System # 1; Peer-to-peer (Symmetric), private-NNI protocol. Spec == Oftel’s ND1301:2001/03 (previously BTNR 188); • Industry standard for PBX inter-connection (or Centrex customers hosted off COs); Deployed in UK, NZ, Australia, India and parts of NA; ISDN-like; similar to QSIG (Europe/Germany); • Approximately 250+ suppl services (like Call Back When Free, Call Back When Next Used, Executive Intrusion, Travelling Class of Service, Do Not Disturb, Night Service, Private Network Route Optimization, Centralized Operator, Three Party Takeover, Remote Diversion Registration etc ….). Deployment Scenario 1 – Basic: PBX PBX DPNSS T1/E1 Deployment Scenario 2 – VPN: ISUP (DPNSS tunnel) CO CO PBX PBX {PSTN} H.323(DPNSS tunnel) H323GW H323GW
DPNSS SIP GW DPNSS SIP GW MGC MGC SIP (DPNSS MIME) MG/ SG MG/ SG B A PBX PBX DUA (SIGTRAN WG: draft-ietf-sigtran-dua-05.txt) Is there a Need for DPNSS MIME in SIP?? • DUA is already past the WGLC on SIGTRAN. For inter-MGC scenarios we need DPNSS-MIME is SIP. • Service Provider trials (e.g., H.323 to SIP migration in VPN/Enterprises that have DPNSS PBXs). • As discussed on the list; DPNSS is the only missing link (QSIG and ISUP MIME exist) so we are not opening a flood-gate. • DPNSSSIP translation is a complementary mechanism – we are working on it; NOT an alternative. • Translation is required to complete calls along routes/nodes that supports only partial DPNSS service transparency. • DPNSS MIME is required for complete service transparency – would be almost impossible to map every detail of DPNSS to SIP (as is the case with ISUP and QSIG)
What is the (primary) difference between DPNSS MIME and QSIG/ISUP MIME?? • Similar to RFC 3204 (MIME objects for ISUP/QSIG) i.e., same Content-Disposition Header etc.. • Mandates single binary coded octet message length field appended to the DPNSS PDU as the first byte. • Specifies message Buffering Option (Detailed description of the usage & examples). • Mandates DPNSS SIP gateway to be modeled as a Transit PBX (Explained with an example). • Mandates single DPNSS call per SIP dialogue. • Specifies use of Version Parameter in DPNSS context.
Does the DPNSS Message Semantic Match with SIP?? • Not an exhaustive list – e.g., messages like Recall Message (RM) does not find a equivalent match (hence have to use SIP INFO Method) • DPNSS Maintenance Messages are of local significance and hence need not be tunneled)
Conclusion • Can be progressed as a WG I-D. • Does not seem to be orthogonal to what SIPPING set out to do. • Has been fairly (sufficiently?) discussed and reviewed on the list. • Submit a DPNSS SIP translation I-D that complements the MIME I-D. (shall provide a Oftel and/or BTNR contact at that stage to assist in reviews)