1、 ECMA-360 1stEdition / December 2004 Corporate Telecommunication Networks - Signalling Interworking between QSIG and SIP - Call Diversion Standard ECMA-360 1stEdition / December 2004 Corporate Telecommunication Networks - Signalling Interworking between QSIG and SIP - Call Diversion Ecma Internation
2、al Rue du Rhne 114 CH-1204 Geneva T/F: +41 22 849 6000/01 www.ecma-international.org IW Ecma-360.doc 14.12.2004 10:45 . Brief history This Standard is one of a series of Ecma Standards defining the interworking of services and signalling protocols deployed in corporate telecommunication networks (CN
3、s) (also known as enterprise networks). The series uses telecommunication concepts as developed by ITU-T and conforms to the framework of International Standards on Open Systems Interconnection as defined by ISO/IEC. It has been produced under ETSI work item DTS/ECMA-00296. This Standard specifies i
4、nterworking between the Session Initiation Protocol (SIP) and QSIG within corporate telecommunication networks (also known as enterprise networks) for calls that undergo diversion. SIP is an Internet application-layer control (signalling) protocol for creating, modifying, and terminating sessions wi
5、th one or more participants. These sessions include, in particular, telephone calls. QSIG is a signalling protocol for creating, modifying and terminating circuit-switched calls, in particular telephone calls, within Private Integrated Services Networks (PISNs). QSIG is specified in a number of Ecma
6、 Standards and published also as ISO/IEC International Standards. This Standard is based upon the practical experience of Ecma member companies and the results of their active and continuous participation in the work of ISO/IEC JTC1, ITU-T, IETF, ETSI and other international and national standardiza
7、tion bodies. It represents a pragmatic and widely based consensus. This Ecma Standard has been adopted by the General Assembly of December 2004. Table of contents 1 Scope 1 2 References 1 3 Terms and definitions 2 3.1 External definitions 2 3.2 Other definitions 2 3.2.1 Call diversion 2 3.2.2 Call f
8、orwarding busy (CFB) 2 3.2.3 Call forwarding no reply (CFNR) 2 3.2.4 Call forwarding unconditional (CFU) 2 3.2.5 Corporate telecommunication Network (CN) 2 3.2.6 Entity A 2 3.2.7 Entity B 3 3.2.8 Entity C 3 3.2.9 Gateway 3 3.2.10 IP network 3 3.2.11 Leg A 3 3.2.12 Leg B 3 3.2.13 Leg C 3 3.2.14 Priva
9、te Integrated Services Network (PISN) 3 3.2.15 Private Integrated services Network eXchange (PINX) 3 3.2.16 Rerouting entity 3 3.2.17 User A 3 3.2.18 User B 3 3.2.19 User C 3 4 Abbreviations and acronyms 3 5 Background and architecture for SIP-QSIG interworking 4 6 Call diversion 4 7 Call diversion
10、in QSIG 5 8 Call diversion in SIP 6 9 Diversion interworking 6 9.1 Scenarios for diversion interworking 6 - i - 9.2 Mapping of numbers, names and URIs 7 9.3 Derivation of QSIG diversion reasons 7 9.3.1 Scenario A1 7 9.3.2 Scenario B1 8 9.3.3 Scenario C2 8 9.4 Derivation of SIP response codes (scenar
11、ios A2 and C1) 8 9.5 Mapping the QSIG diversion counter 8 9.6 Privacy considerations 9 9.7 Interworking for scenario A1 9 9.7.1 Transmitting a SIP INVITE request 9 9.7.2 Receipt of a SIP 1xx or 2xx response 9 9.7.3 Receipt of a SIP 4xx, 5xx or 6xx response 10 9.8 Interworking for scenario A2 10 9.8.
12、1 Receipt of a SIP INVITE request 10 9.8.2 Receipt of a QSIG divertingLegInformation1 invoke APDU 10 9.8.3 Receipt of a QSIG divertingLegInformation3 invoke APDU 10 9.8.4 Transmitting a SIP response in which History-Info is allowed 11 9.9 Interworking for scenario B1 11 9.9.1 Receipt of a SIP 3xx re
13、sponse 11 9.9.2 Receipt of a QSIG DISCONNECT or FACILITY message containing a callRerouteing return result APDU 13 9.9.3 Receipt of a QSIG FACILITY message containing a callRerouteing return error APDU 13 9.9.4 Receipt of a QSIG FACILITY message containing a cfnrDivertedLegFailed invoke APDU 13 9.10
14、 Interworking for scenario B2 13 9.10.1 Receipt of a QSIG FACILITY message containing a CallRerouteing invoke APDU 13 9.11 Interworking for scenario C1 14 9.11.1 Receipt of a QSIG SETUP message containing a divertingLegInformation2 invoke APDU 14 9.11.2 Transmitting a QSIG CONNECT message 14 9.12 In
15、terworking for scenario C2 14 9.12.1 Transmitting a QSIG SETUP message 14 9.12.2 Receipt of a QSIG message containing a divertingLegInformation3 invoke APDU 15 9.12.3 Sending History-Info in a response 15 10 Example message sequences 16 10.1 Scenario A1 16 10.1.1 Successful call history information
16、in 200 response 16 10.1.2 Successful call history information in provisional response 17 10.1.3 Failed call 18 10.2 Scenario A2 18 10.2.1 Successful call CFU or CFB 19 - ii - 10.2.2 Successful call CFNR 20 10.3 Scenario B1 21 10.3.1 Successful diversion CFU or CFB 21 10.3.2 Successful diversion CFNR
17、 22 10.3.3 Failure callRerouting.err received 23 10.3.4 Failure No answer following CFNR 24 10.4 Scenario B2 25 10.5 Scenario C1 26 10.6 Scenario C2 27 10.7 Scenario A1 followed by B1 28 10.8 Scenario A2 followed by scenario B2 29 10.9 Scenario C1 followed by scenario A1 30 10.10 Scenario C2 followe
18、d by scenario A2 31 10.11 Scenario C1 followed by scenario B1 32 10.12 Scenario C2 followed by scenario B2 33 11 Security considerations 33 - iii - 1 Scope This document specifies signalling interworking between “QSIG“ and the Session Initiation Protocol (SIP) in support of call diversion within cor
19、porate telecommunication networks (CN), also known as enterprise networks. “QSIG“ is a signalling protocol that operates between Private Integrated services Network eXchanges (PINX) within a Private Integrated Services Network (PISN). A PISN provides circuit-switched basic services and supplementary
20、 services to its users. QSIG is specified in Ecma Standards, in particular 1 (call control in support of basic services), 2 (generic functional protocol for the support of supplementary services) and a number of Standards specifying individual supplementary services. Diversion services are specified
21、 in 4 and the QSIG signalling protocol in support of these services is specified in 5. In particular, this signalling protocol signals information about call diversion to the users involved. SIP is an application layer protocol for establishing, terminating and modifying multimedia sessions. It is t
22、ypically carried over IP 8, 10. Telephone calls are considered as a type of multimedia session where just audio is exchanged. SIP is defined in 11. An extension to SIP provides history information 14 that can be used to signal information about the retargeting of a request, in particular a call esta
23、blishment request, as it is routed through a network. This document specifies signalling interworking for call diversion during the establishment of calls between a PISN employing QSIG and a corporate IP network employing SIP. It covers both the impact on SIP of call diversion in the QSIG network an
24、d the impact on QSIG of request retargeting in the SIP network. Signalling interworking for call diversion operates on top of signalling interworking for basic calls, which is specified in 6. Call diversion interworking between a PISN employing QSIG and a public IP network employing SIP is outside t
25、he scope of this specification. However, the functionality specified in this specification is in principle applicable to such a scenario when deployed in conjunction with other relevant functionality (e.g., number translation, security functions, etc.). This specification is applicable to any interw
26、orking unit that can act as a gateway between a PISN employing QSIG and a corporate IP network employing SIP. 2 References 1 International Standard ISO/IEC 11572 “Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Circuit mode
27、 bearer services - Inter-exchange signalling procedures and protocol“ (also published by Ecma as Standard ECMA-143). 2 International Standard ISO/IEC 11582 “Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Generic functional
28、 protocol for the support of supplementary services - Inter-exchange signalling procedures and protocol“ (also published by Ecma as Standard ECMA-165). 3 International Standard ISO/IEC 13868 “Information technology - Telecommunications and information exchange between systems - Private Integrated Se
29、rvices Network - Inter-exchange signalling protocol - Name identification supplementary services“ (also published by Ecma as Standard ECMA-164). 4 International Standard ISO/IEC 13872 “Information technology - Telecommunications and information exchange between systems - Private Integrated Services
30、Network - Specification, functional model and information flows - Call Diversion supplementary services“ (also published by Ecma as Standard ECMA-173). 5 International Standard ISO/IEC 13873 “Information technology - Telecommunications and information exchange between systems - Private Integrated Se
31、rvices Network - Inter-exchange signalling protocol - Call Diversion supplementary services“ (also published by Ecma as Standard ECMA-174). - 1 - 6 International Standard ISO/IEC 17343 “Information technology - Telecommunications and information exchange between systems - Corporate telecommunication
32、 networks - Signalling interworking between QSIG and SIP - Basic services“ (also published by Ecma as Standard ECMA-339). 7 Ecma Technical Report TR/86, “Corporate Telecommunication Networks User Identification in a SIP/QSIG Environment“. 8 J. Postel, “Internet Protocol“, RFC 791. 9 Bradner, S., “Ke
33、y words for use in RFCs to Indicate Requirement Levels“, BCP 14, RFC 2119. 10 S. Deering, R. Hinden, “Internet Protocol, Version 6 (IPv6)“, RFC 2460. 11 J. Rosenberg, H. Schulzrinne, et al., “SIP: Session initiation protocol“, RFC 3261. 12 J. Peterson, “A Privacy Mechanism for the Session Initiation
34、 Protocol (SIP)“, RFC 3323. 13 H. Schulzrinne, D. Oran, G. Camarillo, “The Reason Header field for the Session Initiation Protocol (SIP)“, RFC 3326. 14 M. Barnes “An Extension to the Session Initiation Protocol for Request History Information“, draft-ietf-sipping-history-info-03 (work in progress).
35、3 Terms and definitions In this document, the key words “MUST“, “MUST NOT“, “REQUIRED“, “SHALL“, “SHALL NOT“, “SHOULD“, “SHOULD NOT“, “RECOMMENDED“, “MAY“, and “OPTIONAL“ are to be interpreted as described in RFC 2119 9 and indicate requirement levels for compliant implementations. For the purposes
36、of this specification, the following definitions apply. 3.1 External definitions The definitions in 1 and 11 apply as appropriate. 3.2 Other definitions 3.2.1 Call diversion The act of retargeting a call during call establishment by changing the user identity that is used as the basis for routing to
37、 the destination. 3.2.2 Call forwarding busy (CFB) Call diversion invoked because the targeted user is busy. 3.2.3 Call forwarding no reply (CFNR) Call diversion invoked because the targeted user fails to reply within a certain time. 3.2.4 Call forwarding unconditional (CFU) Call diversion invoked f
38、or reasons other than those leading to CFB or CFNR. 3.2.5 Corporate telecommunication Network (CN) Sets of privately-owned or carrier-provided equipment that are located at geographically dispersed locations and are interconnected to provide telecommunication services to a defined group of users. NO
39、TE 1 A CN can comprise a PISN, a private IP network (intranet) or a combination of the two. NOTE 2 Also known as enterprise network. 3.2.6 Entity A The entity that provides information about diversion to user A. - 2 - 3.2.7 Entity B The entity that invokes diversion for a call targeted at user B. 3.
40、2.8 Entity C The entity that provides information about diversion to user C. 3.2.9 Gateway An entity that performs interworking between a PISN using QSIG and an IP network using SIP. 3.2.10 IP network A network, unless otherwise stated a corporate network, offering connectionless packet-mode service
41、s based on the Internet Protocol (IP) as the network layer protocol. 3.2.11 Leg A The call segment between entity A and the rerouting entity for a call that undergoes diversion. 3.2.12 Leg B The call segment between the rerouting entity and entity B for a call that undergoes diversion. 3.2.13 Leg C
42、The call segment between the rerouting entity and entity C for a call that undergoes diversion. 3.2.14 Private Integrated Services Network (PISN) A CN or part of a CN that employs circuit-switched technology. 3.2.15 Private Integrated services Network eXchange (PINX) A PISN nodal entity comprising s
43、witching and call handling functions and supporting QSIG signalling in accordance with 1. 3.2.16 Rerouting entity The entity that performs call rerouting on request from entity B and that provides information about diversion to entity A and entity C. 3.2.17 User A The calling user of a call that und
44、ergoes diversion. 3.2.18 User B The user on behalf of which call diversion is invoked for an incoming call to that user. 3.2.19 User C The user to which a call is diverted. 4 Abbreviations and acronyms APDU Application Protocol Data Unit CFB Call forwarding busy CFNR Call forwarding no reply CFU Cal
45、l forwarding unconditional IP Internet Protocol PINX Private Integrated services Network eXchange PISN Private Integrated Services Network SIP Session Initiation Protocol UA User Agent UAC User Agent Client UAS User Agent Server URI Universal Resource Identifier - 3 - 5 Background and architecture f
46、or SIP-QSIG interworking The background and architecture of 6 applies. In addition, the interworking function in the protocol model handles interworking for call diversion services. This involves interworking between the QSIG call diversion protocol specified in 5 and SIP, including the use of SIP r
47、equest history information as specified in 14. 6 Call diversion Call diversion, as specified in QSIG and for the purposes of this document, is the act of retargeting a call during call establishment by changing the user identity that is used as the basis for routing to the destination. This can be v
48、iewed as being a change of destination user, although in some cases two identities can belong to the same user, e.g., a home number and office number. The three users involved are known as user A (the calling user A), user B (the called user or diverting user) and user C (the diverted-to user). Reas
49、ons for invoking diversion are various and can depend on factors such as the state of the line serving user B, the time of day and the type or identity of user A. It could also be as a result of action by user B in response to the arrival of a call (sometimes known as call deflection). A diversion can occur immediately, i.e. without alerting user B, or after a period of alerting without reply. With the exception of call deflection, diversion requirements must be pre-configured into some
