SIST ES 283 027 V2.4.0:2008

Final draft ETSI ES 283 027 V2.4.0 (2008-01)
ETSI Standard

Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN);
Endorsement of the SIP-ISUP Interworking between the
IP Multimedia (IM) Core Network (CN) subsystem
and Circuit Switched (CS) networks
[3GPP TS 29.163 (Release 7), modified]

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2 Final draft ETSI ES 283 027 V2.4.0 (2008-01)



Reference
RES/TISPAN-03119-NGN-R2
Keywords
endorsement, interworking, ISUP, SIP
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3 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
Contents
Intellectual Property Rights.4
Foreword.4
1 Scope.5
2 References.5
2.1 Normative references.5
3 Definitions and abbreviations.8
Endorsement notice .8
Global modifications to 3GPP TS 29.163 Release 7.8
Annex A (informative): Change history .26
History .27

ETSI

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4 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This ETSI Standard (ES) has been produced by ETSI Technical Committee Telecommunications and Internet
converged Services and Protocols for Advanced Networking (TISPAN), and is now submitted for the ETSI standards
Membership Approval Procedure.
ETSI

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5 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
1 Scope
The present document provides the ETSI endorsement of the 3GPP TS 29.163 [1].
Clauses 7.2.3 and 7.4 of 3GPP TS 29.163 [1] specify the signalling interworking between ISDN User Part (ISUP)
protocols and SIP in order to support services that can be commonly supported by ISUP and SIP-based network
domains.
Clause 9.2.3.3.5 specifies how ringing tone is applied at the gateway when interworking ISUP and SIP.
The present document specifies the principles of interworking between the ETSI TISPAN IMS and ISUP based legacy
CS networks, in order to support IM basic voice calls, therefore all the references to interworking between IMS and
BICC are out of scope of the present document.
The present document is a protocol interworking specification; therefore all references to the user plane interworking
are out of scope of the present document.
The present document specifies the interworking between ETSI SIP profile (as specified within ES 283 003 [3]) and
ISUP, as specified in EN 300 356-1 [2] respectively.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably,
the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the
reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the
method of access to the referenced document and the full network address, with the same punctuation and use of upper
case and lower case letters.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
[1] 3GPP TS 29.163: "3rd Generation Partnership Project; Technical Specification Group Core
Network and Terminals; Interworking between the IP Multimedia (IM) Core Network (CN)
subsystem and Circuit Switched (CS) networks (Release 7)".
[2] ETSI EN 300 356-1 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 1: Basic services
[ITU-T Recommendations Q.761 to Q.764 (1999) modified]".
ETSI

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6 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
[3] ETSI ES 283 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Call Control Protocol based on Session
Initiation Protocol (SIP) and Session Description Protocol (SDP) Stage 3
[3GPP TS 24.229 (Release 7), modified]".
[4] ETSI ES 282 007: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Subsystem (IMS); Functional architecture".
[5] ETSI EN 300 356-3 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 3: Calling Line
Identification Presentation (CLIP) supplementary service [ITU-T Recommendation Q.731,
clause 3 (1993) modified]".
[6] ETSI EN 300 356-4 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 4: Calling Line
Identification Restriction (CLIR) supplementary service [ITU-T Recommendation Q.731,
clause 4 (1993) modified]".
[7] ETSI EN 300 356-5 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 5: Connected
Line Identification Presentation (COLP) supplementary service [ITU-T Recommendation Q.731,
clause 5 (1993) modified]".
[8] ETSI EN 300 356-6 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 6: Connected
Line Identification Restriction (COLR) supplementary service [ITU-T Recommendation Q.731,
clause 6 (1993) modified]".
[9] ETSI EN 300 356-7 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 7: Terminal
Portability (TP) supplementary service [ITU-T Recommendation Q.733, clause 4 (1993)
modified]".
[10] ETSI EN 300 356-8 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 8: User-to-User
Signalling (UUS) supplementary service [ITU-T Recommendation Q.737, clause 1 (1997)
modified]".
[11] ETSI EN 300 356-9 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 9: Closed User
Group (CUG) supplementary service [ITU-T Recommendation Q.735, clause 1 (1993) modified]".
[12] ETSI EN 300 356-10 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface;
Part 10: Subaddressing (SUB) supplementary service [ITU-T Recommendation Q.731, clause 8
(1992) modified]".
[13] ETSI EN 300 356-11 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 11: Malicious
Call Identification (MCID) supplementary service [ITU-T Recommendation Q.731, clause 7
(1997) modified]".
[14] ETSI EN 300 356-12 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 12: Conference
call, add-on (CONF) supplementary service [ITU-T Recommendation Q.734, clause 1 (1993) and
implementors guide (1998) modified]".
[15] ETSI EN 300 356-14 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 14: Explicit Call
Transfer (ECT) supplementary service [ITU-T Recommendation Q.732, clause 7 (1996) and
implementors guide (1998) modified]".
ETSI

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7 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
[16] ETSI EN 300 356-15 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 15: Diversion
supplementary service [ITU-T Recommendation Q.732, clauses 2 to 5 (1999) modified]".
[17] ETSI EN 300 356-16 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface;
Part 16: Call Hold (HOLD) supplementary service [ITU-T Recommendation Q.733,
clause 2 (1993) modified]".
[18] ETSI EN 300 356-17 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface;
Part 17: Call Waiting (CW) supplementary service [ITU-T Recommendation Q.733,
clause 1 (1992) modified]".
[19] ETSI EN 300 356-18 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 18: Completion
of Calls to Busy Subscriber (CCBS) supplementary service [ITU-T Recommendation Q.733,
clause 3 (1997) modified]".
[20] ETSI EN 300 356-19 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface;
Part 19: Three-Party (3PTY) supplementary service [ITU-T Recommendation Q.734,
clause 2 (1996) and implementors guide (1998) modified]".
[21] ETSI EN 300 356-20 (V4.3.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 20: Completion
of Calls on No Reply (CCNR) supplementary service [ITU-T Recommendation Q.733, clause 5
(1999) modified]".
[22] ETSI EN 300 356-21: "Integrated Services Digital Network (ISDN); Signalling System No.7
(SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 21: Anonymous Call
Rejection (ACR) supplementary service [ITU-T Recommendation Q.731, clause 4 (1993)]".
[23] ETSI EN 300 485 (V1.2.3): "Integrated Services Digital Network (ISDN); Definition and usage of
cause and location in Digital Subscriber Signalling System No. one (DSS1) and Signalling System
No. 7 (SS7) ISDN User Part (ISUP) [ITU-T Recommendation Q.850 (1998) with addendum
modified]".
[24] ETSI EN 300 403-1: "Integrated Services Digital Network (ISDN); Digital Subscriber Signalling
System No. one (DSS1) protocol; Signalling network layer for circuit-mode basic call control;
Part 1: Protocol specification [ITU-T Recommendation Q.931 (1993), modified]".
[25] IETF RFC 3966 (December 2004): "The tel URI for Telephone Numbers".
ETSI

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8 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
3 Definitions and abbreviations
For the purposes of the present document, the terms, definitions and abbreviations given in 3GPP TS 29.163 [1],
clauses 7.2.3 and 7.4 apply.
Endorsement notice
The present document endorses 3GPP TS 29.163: "3rd Generation Partnership Project; Technical Specification Group
Core Network and Terminals; Interworking between the IP Multimedia (IM) Core Network (CN) subsystem and Circuit
Switched (CS) networks (Release 7)" [1], the contents of which apply together with the following modifications:
Clauses 6.3, 7.3, 8, 9.2.2.1, 9.2.2.2, 9.2.3.1, 9.2.3.2, 9.2.4.1, 9.2.5.1, 9.2.6.1, 9.2.7.1, 9.2.8.1, 9.2.8.3 and annex B do not
apply to this recommendation.
NOTE: Underlining and/or strike-out are used to highlight detailed modifications where necessary.
Global modifications to 3GPP TS 29.163 Release 7
Throughout the text of the 3GPP TS 29.163 Release 7
Replace references as shown in table 1.
Table 1
References in 3GPP TS 29.163 [1] Replaced references
ITU-T Recommendation Q.761 EN 300 356-1 [2]
ITU-T Recommendation Q.762 EN 300 356-1 [2]
ITU-T Recommendation Q.763 EN 300 356-1 [2]
ITU-T Recommendation Q.764 EN 300 356-1 [2]
3GPP TS 24.229 ES 283 003 [3]
3GPP TS 23.228 ES 282 007 [4]
ITU-T Recommendation Q.850 (1998) EN 300 485 [23]
ITU-T Recommendation Q.731.3 EN 300 356-3 [5]
ITU-T Recommendation Q.731.4 EN 300 356-4 [6]
ITU-T Recommendation Q.731.5 EN 300 356-5 [7]
ITU-T Recommendation Q.731.6 EN 300 356-6 [8]
ITU-T Recommendation Q.731.7 EN 300 356-11 [13]
ITU-T Recommendation Q.731.8 EN 300 356-10 [12]
ITU-T Recommendation Q.732.2 EN 300 356-15 [16]
ITU-T Recommendation Q.732.3 EN 300 356-15 [16]
ITU-T Recommendation Q.732.4 EN 300 356-15 [16]
ITU-T Recommendation Q.732.5 EN 300 356-15 [16]
ITU-T Recommendation Q.732.7 EN 300 356-14 [15]
ITU-T Recommendation Q.733.1 EN 300 356-17 [18]
ITU-T Recommendation Q.733.2 EN 300 356-16 [17]
ITU-T Recommendation Q.733.3 EN 300 356-18 [19]
ITU-T Recommendation Q.733.4 EN 300 356-7 [9]
ITU-T Recommendation Q.733.5 EN 300 356-20 [21]
ITU-T Recommendation Q.734.1 EN 300 356-12 [14]
ITU-T Recommendation Q.734.2 EN 300 356-19 [20]
ITU-T Recommendation Q.735.1 EN 300 356-9 [11]
ITU-T Recommendation Q.737.1 EN 300 356-8 [10]

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9 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
Clause 2
Modify as follows:
[77] IETF draft-ietf-sip-acr-code-03 "Rejecting Anonymous Requests in the Session Initiation Protocol
(SIP)"
[77] IETF RFC 5079: "Rejecting Anonymous Requests in the Session Initiation Protocol (SIP)".
[89] draft-ejzak-sipping-p-em-auth-03.txt (January 2007): "Private Header (P-Header) Extension to the
Session Initiation Protocol (SIP) for Authorization of Early Media".
[89] IETF RFC 5009: "Private Header (P-Header) Extension to the Session Initiation Protocol (SIP) for
Authorization of Early Media".
[91] ETSI EN 300 403-1: "Integrated Services Digital Network (ISDN); Digital Subscriber Signalling
System No. one (DSS1) protocol; Signalling network layer for circuit-mode basic call control; Part
1: Protocol specification [ITU-T Recommendation Q.931 (1993), modified]".
[92] IETF RFC 3966: "The tel URI for Telephone Numbers".
[93] ISO/IEC 8348: "Information technology Open Systems Interconnection Network service
definition".
Clause 7.2.3.1.2.5 Transmission medium requirement
Modify as follows:
The I-MGCF may either transcode the selected codec(s) to the codec on the PSTN side or it may attempt to interwork
the media without transcoding. If the I-MGCF transcodes, it shall select the TMR parameter to "3,1 kHz audio". If the
I-MGCF does not transcode, it should map the TMR, USI and Access Transport parameters from the selected codec
according to table 2a. The support of any of the media listed in table 2a is optional. The SDP for the data transfer with
64 kbit/s clearmode shall be mapped to the TMR "64 kbit/s unrestricted".
If the XML BearerCapability element is received in the INVITE the mapping of the USI shall be taken from the
BearerCapability XML, else the USI shall be derived from the SDP attributes as shown in table2a.
Add clause 7.2.3.1.2.1.5a
7.2.3.1.2.5a Transmission medium requirement prime and USI prime (optional)
The Fallback mechanism shall only apply if a XML Bearer Capability element appears within the INVITE Request.
When the INVITE request includes multiple audio codecs with codec appearing in table 2a then the I-MGCF shall:
- If the first stated codec in the INVITE is a codec appearing in table 2a and is the equivalent as stated within the
second Bearer Capability in the XML Bearer Capability element then the I-MGCF shall map the XML Bearer
Capability element into the TMR and USI prime.
- If the second stated codec in the INVITE is a codec appearing in table 2a and is the equivalent as stated within
the first Bearer Capability in the XML Bearer Capability element then the I-MGCF shall map the XML Bearer
Capability element into the TMR prime and USI.
- If the compared codec stated within the INVITE is not equivalent as stated within XML Bearer Capability
element then the XML Bearer Capability element shall be discarded.
If the Fallback mechanism is not supported by the terminating network the procedures as described within
clause 7.2.3.1.2.5 shall apply.
In cases where the fallback appears within the terminating entity and sends back a codec to which is fallen back then the
I-MGCF shall only apply the cut-though to the chosen codec.
In cases where the fallback appears within the terminating entity and sends back a SDP Answer that is equivalent with
the TMR prime codec (fallback codec) then the I-MGCF shall only apply the cut-though to the fallback codec.

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10 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
In cases where preconditions are used the I-MGCF has to wait for the SDP answer where the preconditions are met and
fallback codec is sent back.
Add clause 7.2.3.1.2.10
7.2.3.1.2.10 Access Transport Parameter and User Tele Service
When an INVITE was received containing a PSTN XML body as defined in ES 283 003 [3], an available
"ProgressIndicator" element can be as a network option mapped into a Progress Indicator in the Access Transport
Parameter of the sent IAM
Table 7a0.1: Mapping of PSTN XML elements with ISUP Parameters
INVITE  IAM
PSTN XML ISUP Parameter Content
ProgressIndicator ProgresAccess Transport Parameter s indicator
HighLayerCompatibility High layer compatibility (Note)
LowLayerCompatibility Low layer compatibility
BearerCapability User Service Information
HighLayerCompatibility User Tele Service High layer compatibility (Note)
NOTE: If two high layer compatibility information elements are received, they are transferred in the same order as
received in the INVITE message in the access transport parameter of the initial address message.

Clause 7.2.3.1.4 Sending of 180 ringing
Modify as follows:
The I-MGCF shall send the SIP 180 Ringing when receiving any of the following messages:
- ACM with Called party's status indicator set to subscriber free.

I-MGCF
ACM
180 Ringing
(Subscriber Free)
P-Early-Media (1)
Ring tone

NOTE: Including the P-Early-Media Header is a network option for a speech call.

Figure 6: The receipt of ACM
- CPG with Event indicator set to alerting
I-MGCF
180 Ringing
CPG (Alerting)
P-Early-Media (1)
Ring tone


NOTE: Including the P-Early-Media Header is a network option for a speech call.

Figure 7: Receipt of CPG (Alerting)
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11 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
For a speech call, if the I-MGCF supports the P-Early-Media header as a network option, and if the INVITE request
includes the P-Early-Media header, the I-MGCF shall include in the SIP 180 ringing response a P-Early-Media header
authorizing early media, except when:
- the I-MGCF has already sent a reliable provisional response including a P-Early-Media header, as defined in
RFC5009 [89]; and
- the most recently sent P-Early-Media header authorized early media.
NOTE: If the I-MGCF signals the P-Early-Media header authorizing early media, then the IMS can expect tones
or announcements to the calling party to flow from the CS network via an MGW controlled by the
I-MGCF. In particular, once the I-MGCF sends the 180 Ringing response, ringback is expected in media
from the CS network.
Received PSTN XML elements shall be mapped as shown in table 7a0.2.
Table 7a0.2: ISUP Parameters with Mapping of PSTN XML elements
18x CPG or ACM
PSTN XML ISUP Parameter Content
ProgressIndicator ProgresAccess Transport Parameter s indicator
HighLayerCompatibility High layer compatibility (Note)
LowLayerCompatibility Low layer compatibility
NOTE: If two high layer compatibility information elements are received, they are transferred in the same order as
received in the INVITE message in the access transport parameter of the initial address message.

Table 7a0.3: Sending criteria of the XML with Progress indicator X
← 180 Ringing ←ACM
PSTN XML body with Progress indicator X Content
No. 1 Backward call indicators parameter
(Call is not end-to-end ISDN: further progress information may ISDN User Part indicator
be available in-band)  0 ISDN User Part not used all the way
No. 2 Backward call indicators parameter
(Destination address is non-ISDN) ISDN User Part indicator
 1 ISDN User Part used all the way
ISDN access indicator
 0 Terminating access non-ISDN
No. 4 Backward call indicators parameter
(Call is returned to ISDN)   ISDN User Part indicator
 1 ISDN User Part used all the way
ISDN access indicator
 1 Terminating access ISDN

Progress indicator
Progress indicator information elements possibly present in the access transport parameter of the Address Complete
Message (ACM) are transferred into the PSTN XML body (as defined in ES 283 003 [3]) of the 180 Ringing sent to the
calling user.
Clause 7.2.3.1.4A Sending of 183 Session Progress for early media scenarios
Modify as follows:
If SIP preconditions are used, the first 183 Session Progress will be sent after the reception of the INVITE request,
before any ISUP message has been received from the CS network. The I-MGCF shall not include the P-Early-Media
header in any SIP message before it receives an ISUP ACM.
On receipt of an ACM with the options described in table 7a2 the I-MGCF can be sent, as a network option, a
183 Session Progress response with following options:
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12 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
Table 7a2: Sending criteria of the XML with Progress indicator X
← 183 Session Progress ←ACM
PSTN XML body with Progress indicator X Content
No. 1 Backward call indicators parameter
(Call is not end-to-end ISDN: further progress information ISDN User Part indicator
may be available in-band)  0 ISDN User Part not used all the way
No. 2 Backward call indicators parameter
(Destination address is non-ISDN) ISDN User Part indicator
 1 ISDN User Part used all the way
ISDN access indicator
 0 Terminating access non-ISDN
No. 4 Backward call indicators parameter
(Call is returned to ISDN)   ISDN User Part indicator
 1 ISDN User Part used all the way
ISDN access indicator
 1 Terminating access ISDN

Progress indicator
Progress indicator information elements possibly present in the access transport parameter of the Address Complete
Message (ACM) are transferred into the PSTN XML body (as defined in ES 283 003 [3]) of the 183 Session Progress
sent to the calling user.
For a speech call upon receipt of one of the following messages, if the I-MGCF supports the P-Early-Media header as a
network option, and if the I-MGCF has received the P-Early-Media header in the INVITE request, and has not already
sent a provisional response including a P-Early-Media header with parameters indicating authorization of early media,
then the I-MGCF shall send the 183 Session Progress response with a P-Early-Media header authorizing early media:
- ACM with the value of the called party's status indicator "no indication" and one of the options described in
table 7a1. Based on local configuration, the I-MGCF may also send a 183 Session Progress response with a
P-Early-Media header authorizing early media if it receives an ACM with other parameters than described in
table 7a1.

I-MGCF
ACM
183 Progress
(No indication)
P-Early-Media
appropriate announcement

Figure 7c: Receipt of ACM "No indication"
Table 7a.1: ACM Parameters that trigger the 183 Session Progress response
←183 Session Progress ←ACM

1 ）Optional backward call indicators parameter
183 Session Progress response including a P-Early-Media
In-band information indicator
header authorizing early media, if not already sent
 1 In-band info.
2 ）Backward call indicators parameter
ISDN User Part indicator
0 ISDN User Part not used all the way

NOTE: As a network option the I-MGCF can also map ACM into 183 in other cases than those described in
table 7a1.
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13 Final draft ETSI ES 283 027 V2.4.0 (2008-01)
- CPG message, when:
1. Event indicator is set to "in-band information or an appropriate pattern is now available"; or
2. Event indicator is set to "Progress" and one of the options described in table 7b1.

I-MGCF
CPG
183 Progress
(in-band information available)
P-Early-Media
appropriate announcment

Figure 7d: Receipt of CPG (in-band information available)
Table 7b.1: CPG Parameters that trigger the 183 Session Progress response
←183 Session Progress ←CPG

Event indicator
183 Session Progress response including a P-Early- 000 0010 (progress)
Media header authorizing early media, if not already
1 ）Optional backward call indicators parameter
sent
In-band information indicator
0 In-band info .
2 ）Backward call indicators parameter
ISDN User Part indicator
0 ISDN User Part not used all the way
NOTE 1: The mapping of the contents in the CPG message is only relevant if the information received in the
message is different compared to earlier received information, e.g. in the ACM message or a CPG
message received prior to this message.
NOTE 2: 183 Session Progress message including a P-Early-Media header authorizing early media may only be
sent for a speech call.

NOTE: As a network option the I-MGCF can also map CPG into 183 in other cases than those described in
table 7a1.
Received PSTN XML elements shall be mapped as shown in table 7a0.2
On receip
...

SLOVENSKI STANDARD
SIST ES 283 027 V2.4.0:2008
01-julij-2008
=OLWHWHOHNRPXQLNDFLMVNHLQLQWHUQHWQHVWRULWYHWHUSURWRNROL]DQDSUHGQRRPUHåHQMH
7,63$13RWUGLWHYPHGVHERMQHJDGHORYDQMD6,3,683PHGSRGVLVWHPRP,3
YHþSUHGVWDYQRVWQHJDMHGUQHJDRPUHåMD&1LQYRGRYQRNRPXWLUDQLPL&6
RPUHåML
Telecommunications and Internet converged Services and Protocols for Advanced
Networking (TISPAN) - Endorsement of the SIP-ISUP Interworking between the IP
Multimedia (IM) Core Network (CN) subsystem and Circuit Switched (CS) networks
Ta slovenski standard je istoveten z: ES 283 027 Version 2.4.0
ICS:
33.040.01 Telekomunikacijski sistemi Telecommunication systems
na splošno in general
33.080 Digitalno omrežje z Integrated Services Digital
integriranimi storitvami Network (ISDN)
(ISDN)
SIST ES 283 027 V2.4.0:2008 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ES 283 027 V2.4.0:2008

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SIST ES 283 027 V2.4.0:2008

ETSI ES 283 027 V2.4.0 (2008-04)
ETSI Standard

Telecommunications and Internet converged Services and
Protocols for Advanced Networking (TISPAN);
Endorsement of the SIP-ISUP Interworking between the
IP Multimedia (IM) Core Network (CN) subsystem
and Circuit Switched (CS) networks
[3GPP TS 29.163 (Release 7), modified]

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SIST ES 283 027 V2.4.0:2008
 2 ETSI ES 283 027 V2.4.0 (2008-04)



Reference
RES/TISPAN-03119-NGN-R2
Keywords
endorsement, interworking, ISUP, SIP
ETSI
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ETSI

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SIST ES 283 027 V2.4.0:2008
 3 ETSI ES 283 027 V2.4.0 (2008-04)
Contents
Intellectual Property Rights.4
Foreword.4
1 Scope.5
2 References.5
2.1 Normative references.5
2.2 Informative references.7
3 Definitions and abbreviations.7
Endorsement notice .8
Global modifications to 3GPP TS 29.163 Release 7.8
Annex A (informative): Change history .26
History .27

ETSI

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SIST ES 283 027 V2.4.0:2008
 4 ETSI ES 283 027 V2.4.0 (2008-04)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://webapp.etsi.org/IPR/home.asp).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This ETSI Standard (ES) has been produced by ETSI Technical Committee Telecommunications and Internet
converged Services and Protocols for Advanced Networking (TISPAN).
ETSI

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SIST ES 283 027 V2.4.0:2008
 5 ETSI ES 283 027 V2.4.0 (2008-04)
1 Scope
The present document provides the ETSI endorsement of the 3GPP TS 29.163 [1].
Clauses 7.2.3 and 7.4 of 3GPP TS 29.163 [1] specify the signalling interworking between ISDN User Part (ISUP)
protocols and SIP in order to support services that can be commonly supported by ISUP and SIP-based network
domains.
Clause 9.2.3.3.5 specifies how ringing tone is applied at the gateway when interworking ISUP and SIP.
The present document specifies the principles of interworking between the ETSI TISPAN IMS and ISUP based legacy
CS networks, in order to support IM basic voice calls, therefore all the references to interworking between IMS and
BICC are out of scope of the present document.
The present document is a protocol interworking specification; therefore all references to the user plane interworking
are out of scope of the present document.
The present document specifies the interworking between ETSI SIP profile (as specified within ES 283 003 [3]) and
ISUP, as specified in EN 300 356-1 [2] respectively.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• Non-specific reference may be made only to a complete document or a part thereof and only in the following
cases:
- if it is accepted that it will be possible to use all future changes of the referenced document for the
purposes of the referring document;
- for informative references.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
For online referenced documents, information sufficient to identify and locate the source shall be provided. Preferably,
the primary source of the referenced document should be cited, in order to ensure traceability. Furthermore, the
reference should, as far as possible, remain valid for the expected life of the document. The reference shall include the
method of access to the referenced document and the full network address, with the same punctuation and use of upper
case and lower case letters.
NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are indispensable for the application of the present document. For dated
references, only the edition cited applies. For non-specific references, the latest edition of the referenced document
(including any amendments) applies.
[1] 3GPP TS 29.163: "3rd Generation Partnership Project; Technical Specification Group Core
Network and Terminals; Interworking between the IP Multimedia (IM) Core Network (CN)
subsystem and Circuit Switched (CS) networks (Release 7)".
[2] ETSI EN 300 356-1 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 1: Basic services
[ITU-T Recommendations Q.761 to Q.764 (1999) modified]".
ETSI

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SIST ES 283 027 V2.4.0:2008
 6 ETSI ES 283 027 V2.4.0 (2008-04)
[3] ETSI ES 283 003: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Call Control Protocol based on Session
Initiation Protocol (SIP) and Session Description Protocol (SDP) Stage 3
[3GPP TS 24.229 (Release 7), modified]".
[4] ETSI ES 282 007: "Telecommunications and Internet converged Services and Protocols for
Advanced Networking (TISPAN); IP Multimedia Subsystem (IMS); Functional architecture".
[5] ETSI EN 300 356-3 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 3: Calling Line
Identification Presentation (CLIP) supplementary service [ITU-T Recommendation Q.731,
clause 3 (1993) modified]".
[6] ETSI EN 300 356-4 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 4: Calling Line
Identification Restriction (CLIR) supplementary service [ITU-T Recommendation Q.731,
clause 4 (1993) modified]".
[7] ETSI EN 300 356-5 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 5: Connected
Line Identification Presentation (COLP) supplementary service [ITU-T Recommendation Q.731,
clause 5 (1993) modified]".
[8] ETSI EN 300 356-6 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 6: Connected
Line Identification Restriction (COLR) supplementary service [ITU-T Recommendation Q.731,
clause 6 (1993) modified]".
[9] ETSI EN 300 356-7 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 7: Terminal
Portability (TP) supplementary service [ITU-T Recommendation Q.733, clause 4 (1993)
modified]".
[10] ETSI EN 300 356-8 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 8: User-to-User
Signalling (UUS) supplementary service [ITU-T Recommendation Q.737, clause 1 (1997)
modified]".
[11] ETSI EN 300 356-9 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 9: Closed User
Group (CUG) supplementary service [ITU-T Recommendation Q.735, clause 1 (1993) modified]".
[12] ETSI EN 300 356-10 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface;
Part 10: Subaddressing (SUB) supplementary service [ITU-T Recommendation Q.731, clause 8
(1992) modified]".
[13] ETSI EN 300 356-11 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 11: Malicious
Call Identification (MCID) supplementary service [ITU-T Recommendation Q.731, clause 7
(1997) modified]".
[14] ETSI EN 300 356-12 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 12: Conference
call, add-on (CONF) supplementary service [ITU-T Recommendation Q.734, clause 1 (1993) and
implementors guide (1998) modified]".
[15] ETSI EN 300 356-14 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 14: Explicit Call
Transfer (ECT) supplementary service [ITU-T Recommendation Q.732, clause 7 (1996) and
implementors guide (1998) modified]".
ETSI

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SIST ES 283 027 V2.4.0:2008
 7 ETSI ES 283 027 V2.4.0 (2008-04)
[16] ETSI EN 300 356-15 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 15: Diversion
supplementary service [ITU-T Recommendation Q.732, clauses 2 to 5 (1999) modified]".
[17] ETSI EN 300 356-16 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface;
Part 16: Call Hold (HOLD) supplementary service [ITU-T Recommendation Q.733,
clause 2 (1993) modified]".
[18] ETSI EN 300 356-17 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface;
Part 17: Call Waiting (CW) supplementary service [ITU-T Recommendation Q.733,
clause 1 (1992) modified]".
[19] ETSI EN 300 356-18 (V4.1.2): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 18: Completion
of Calls to Busy Subscriber (CCBS) supplementary service [ITU-T Recommendation Q.733,
clause 3 (1997) modified]".
[20] ETSI EN 300 356-19 (V4.2.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface;
Part 19: Three-Party (3PTY) supplementary service [ITU-T Recommendation Q.734,
clause 2 (1996) and implementors guide (1998) modified]".
[21] ETSI EN 300 356-20 (V4.3.1): "Integrated Services Digital Network (ISDN); Signalling System
No.7 (SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 20: Completion
of Calls on No Reply (CCNR) supplementary service [ITU-T Recommendation Q.733, clause 5
(1999) modified]".
[22] ETSI EN 300 356-21: "Integrated Services Digital Network (ISDN); Signalling System No.7
(SS7); ISDN User Part (ISUP) version 4 for the international interface; Part 21: Anonymous Call
Rejection (ACR) supplementary service [ITU-T Recommendation Q.731, clause 4 (1993)]".
[23] ETSI EN 300 485 (V1.2.3): "Integrated Services Digital Network (ISDN); Definition and usage of
cause and location in Digital Subscriber Signalling System No. one (DSS1) and Signalling System
No. 7 (SS7) ISDN User Part (ISUP) [ITU-T Recommendation Q.850 (1998) with addendum
modified]".
[24] ETSI EN 300 403-1: "Integrated Services Digital Network (ISDN); Digital Subscriber Signalling
System No. one (DSS1) protocol; Signalling network layer for circuit-mode basic call control;
Part 1: Protocol specification [ITU-T Recommendation Q.931 (1993), modified]".
[25] IETF RFC 3966 (December 2004): "The tel URI for Telephone Numbers".
2.2 Informative references
Not applicable.
3 Definitions and abbreviations
For the purposes of the present document, the terms, definitions and abbreviations given in 3GPP TS 29.163 [1],
clauses 7.2.3 and 7.4 apply.
ETSI

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SIST ES 283 027 V2.4.0:2008
 8 ETSI ES 283 027 V2.4.0 (2008-04)
Endorsement notice
The present document endorses 3GPP TS 29.163: "3rd Generation Partnership Project; Technical Specification Group
Core Network and Terminals; Interworking between the IP Multimedia (IM) Core Network (CN) subsystem and Circuit
Switched (CS) networks (Release 7)" [1], the contents of which apply together with the following modifications:
Clauses 6.3, 7.3, 8, 9.2.2.1, 9.2.2.2, 9.2.3.1, 9.2.3.2, 9.2.4.1, 9.2.5.1, 9.2.6.1, 9.2.7.1, 9.2.8.1, 9.2.8.3 and annex B do not
apply to this recommendation.
NOTE: Underlining and/or strike-out are used to highlight detailed modifications where necessary.
Global modifications to 3GPP TS 29.163 Release 7
Throughout the text of the 3GPP TS 29.163 Release 7
Replace references as shown in table 1.
Table 1
References in 3GPP TS 29.163 [1] Replaced references
ITU-T Recommendation Q.761 EN 300 356-1 [2]
ITU-T Recommendation Q.762 EN 300 356-1 [2]
ITU-T Recommendation Q.763 EN 300 356-1 [2]
ITU-T Recommendation Q.764 EN 300 356-1 [2]
3GPP TS 24.229 ES 283 003 [3]
3GPP TS 23.228 ES 282 007 [4]
ITU-T Recommendation Q.850 (1998) EN 300 485 [23]
ITU-T Recommendation Q.731.3 EN 300 356-3 [5]
ITU-T Recommendation Q.731.4 EN 300 356-4 [6]
ITU-T Recommendation Q.731.5 EN 300 356-5 [7]
ITU-T Recommendation Q.731.6 EN 300 356-6 [8]
ITU-T Recommendation Q.731.7 EN 300 356-11 [13]
ITU-T Recommendation Q.731.8 EN 300 356-10 [12]
ITU-T Recommendation Q.732.2 EN 300 356-15 [16]
ITU-T Recommendation Q.732.3 EN 300 356-15 [16]
ITU-T Recommendation Q.732.4 EN 300 356-15 [16]
ITU-T Recommendation Q.732.5 EN 300 356-15 [16]
ITU-T Recommendation Q.732.7 EN 300 356-14 [15]
ITU-T Recommendation Q.733.1 EN 300 356-17 [18]
ITU-T Recommendation Q.733.2 EN 300 356-16 [17]
ITU-T Recommendation Q.733.3 EN 300 356-18 [19]
ITU-T Recommendation Q.733.4 EN 300 356-7 [9]
ITU-T Recommendation Q.733.5 EN 300 356-20 [21]
ITU-T Recommendation Q.734.1 EN 300 356-12 [14]
ITU-T Recommendation Q.734.2 EN 300 356-19 [20]
ITU-T Recommendation Q.735.1 EN 300 356-9 [11]
ITU-T Recommendation Q.737.1 EN 300 356-8 [10]

ETSI

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SIST ES 283 027 V2.4.0:2008
 9 ETSI ES 283 027 V2.4.0 (2008-04)
Clause 2
Modify as follows:
[77] IETF draft-ietf-sip-acr-code-03 "Rejecting Anonymous Requests in the Session Initiation Protocol
(SIP)"
[77] IETF RFC 5079: "Rejecting Anonymous Requests in the Session Initiation Protocol (SIP)".
[89] draft-ejzak-sipping-p-em-auth-03.txt (January 2007): "Private Header (P-Header) Extension to the
Session Initiation Protocol (SIP) for Authorization of Early Media".
[89] IETF RFC 5009: "Private Header (P-Header) Extension to the Session Initiation Protocol (SIP) for
Authorization of Early Media".
[91] ETSI EN 300 403-1: "Integrated Services Digital Network (ISDN); Digital Subscriber Signalling
System No. one (DSS1) protocol; Signalling network layer for circuit-mode basic call control; Part
1: Protocol specification [ITU-T Recommendation Q.931 (1993), modified]".
[92] IETF RFC 3966: "The tel URI for Telephone Numbers".
[93] ISO/IEC 8348: "Information technology Open Systems Interconnection Network service
definition".
Clause 7.2.3.1.2.5 Transmission medium requirement
Modify as follows:
The I-MGCF may either transcode the selected codec(s) to the codec on the PSTN side or it may attempt to interwork
the media without transcoding. If the I-MGCF transcodes, it shall select the TMR parameter to "3,1 kHz audio". If the
I-MGCF does not transcode, it should map the TMR, USI and Access Transport parameters from the selected codec
according to table 2a. The support of any of the media listed in table 2a is optional. The SDP for the data transfer with
64 kbit/s clearmode shall be mapped to the TMR "64 kbit/s unrestricted".
If the XML BearerCapability element is received in the INVITE the mapping of the USI shall be taken from the
BearerCapability XML, else the USI shall be derived from the SDP attributes as shown in table2a.
Add clause 7.2.3.1.2.1.5a
7.2.3.1.2.5a Transmission medium requirement prime and USI prime (optional)
The Fallback mechanism shall only apply if a XML Bearer Capability element appears within the INVITE Request.
When the INVITE request includes multiple audio codecs with codec appearing in table 2a then the I-MGCF shall:
- If the first stated codec in the INVITE is a codec appearing in table 2a and is the equivalent as stated within the
second Bearer Capability in the XML Bearer Capability element then the I-MGCF shall map the XML Bearer
Capability element into the TMR and USI prime.
- If the second stated codec in the INVITE is a codec appearing in table 2a and is the equivalent as stated within
the first Bearer Capability in the XML Bearer Capability element then the I-MGCF shall map the XML Bearer
Capability element into the TMR prime and USI.
- If the compared codec stated within the INVITE is not equivalent as stated within XML Bearer Capability
element then the XML Bearer Capability element shall be discarded.
If the Fallback mechanism is not supported by the terminating network the procedures as described within
clause 7.2.3.1.2.5 shall apply.
In cases where the fallback appears within the terminating entity and sends back a codec to which is fallen back then the
I-MGCF shall only apply the cut-though to the chosen codec.
In cases where the fallback appears within the terminating entity and sends back a SDP Answer that is equivalent with
the TMR prime codec (fallback codec) then the I-MGCF shall only apply the cut-though to the fallback codec.
ETSI

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 10 ETSI ES 283 027 V2.4.0 (2008-04)
In cases where preconditions are used the I-MGCF has to wait for the SDP answer where the preconditions are met and
fallback codec is sent back.
Add clause 7.2.3.1.2.10
7.2.3.1.2.10 Access Transport Parameter and User Tele Service
When an INVITE was received containing a PSTN XML body as defined in ES 283 003 [3], an available
"ProgressIndicator" element can be as a network option mapped into a Progress Indicator in the Access Transport
Parameter of the sent IAM
Table 7a0.1: Mapping of PSTN XML elements with ISUP Parameters
INVITE  IAM
PSTN XML ISUP Parameter Content
ProgressIndicator ProgresAccess Transport Parameter s indicator
HighLayerCompatibility High layer compatibility (Note)
LowLayerCompatibility Low layer compatibility
BearerCapability User Service Information
HighLayerCompatibility User Tele Service High layer compatibility (Note)
NOTE: If two high layer compatibility information elements are received, they are transferred in the same order as
received in the INVITE message in the access transport parameter of the initial address message.

Clause 7.2.3.1.4 Sending of 180 ringing
Modify as follows:
The I-MGCF shall send the SIP 180 Ringing when receiving any of the following messages:
- ACM with Called party's status indicator set to subscriber free.

I-MGCF
ACM
180 Ringing
(Subscriber Free)
P-Early-Media (1)
Ring tone

NOTE: Including the P-Early-Media Header is a network option for a speech call.

Figure 6: The receipt of ACM
- CPG with Event indicator set to alerting
I-MGCF
180 Ringing
CPG (Alerting)
P-Early-Media (1)
Ring tone


NOTE: Including the P-Early-Media Header is a network option for a speech call.

Figure 7: Receipt of CPG (Alerting)
ETSI

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 11 ETSI ES 283 027 V2.4.0 (2008-04)
For a speech call, if the I-MGCF supports the P-Early-Media header as a network option, and if the INVITE request
includes the P-Early-Media header, the I-MGCF shall include in the SIP 180 ringing response a P-Early-Media header
authorizing early media, except when:
- the I-MGCF has already sent a reliable provisional response including a P-Early-Media header, as defined in
RFC5009 [89]; and
- the most recently sent P-Early-Media header authorized early media.
NOTE: If the I-MGCF signals the P-Early-Media header authorizing early media, then the IMS can expect tones
or announcements to the calling party to flow from the CS network via an MGW controlled by the
I-MGCF. In particular, once the I-MGCF sends the 180 Ringing response, ringback is expected in media
from the CS network.
Received PSTN XML elements shall be mapped as shown in table 7a0.2.
Table 7a0.2: ISUP Parameters with Mapping of PSTN XML elements
18x CPG or ACM
PSTN XML ISUP Parameter Content
ProgressIndicator ProgresAccess Transport Parameter s indicator
HighLayerCompatibility High layer compatibility (Note)
LowLayerCompatibility Low layer compatibility
NOTE: If two high layer compatibility information elements are received, they are transferred in the same order as
received in the INVITE message in the access transport parameter of the initial address message.

Table 7a0.3: Sending criteria of the XML with Progress indicator X
← 180 Ringing ←ACM
PSTN XML body with Progress indicator X Content
No. 1 Backward call indicators parameter
(Call is not end-to-end ISDN: further progress information may ISDN User Part indicator
be available in-band)  0 ISDN User Part not used all the way
No. 2 Backward call indicators parameter
(Destination address is non-ISDN) ISDN User Part indicator
 1 ISDN User Part used all the way
ISDN access indicator
 0 Terminating access non-ISDN
No. 4 Backward call indicators parameter
(Call is returned to ISDN)   ISDN User Part indicator
 1 ISDN User Part used all the way
ISDN access indicator
 1 Terminating access ISDN

Progress indicator
Progress indicator information elements possibly present in the access transport parameter of the Address Complete
Message (ACM) are transferred into the PSTN XML body (as defined in ES 283 003 [3]) of the 180 Ringing sent to the
calling user.
Clause 7.2.3.1.4A Sending of 183 Session Progress for early media scenarios
Modify as follows:
If SIP preconditions are used, the first 183 Session Progress will be sent after the reception of the INVITE request,
before any ISUP message has been received from the CS network. The I-MGCF shall not include the P-Early-Media
header in any SIP message before it receives an ISUP ACM.
ETSI

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On receipt of an ACM with the options described in table 7a2 the I-MGCF can be sent, as a network option, a
183 Session Progress response with following options:
Table 7a2: Sending criteria of the XML with Progress indicator X
← 183 Session Progress ←ACM
PSTN XML body with Progress indicator X Content
No. 1 Backward call indicators parameter
(Call is not end-to-end ISDN: further progress information ISDN User Part indicator
may be available in-band)  0 ISDN User Part not used all the way
No. 2 Backward call indicators parameter
(Destination address is non-ISDN) ISDN User Part indicator
 1 ISDN User Part used all the way
ISDN access indicator
 0 Terminating access non-ISDN
No. 4 Backward call indicators parameter
(Call is returned to ISDN)   ISDN User Part indicator
 1 ISDN User Part used all the way
ISDN access indicator
 1 Terminating access ISDN

Progress indicator
Progress indicator information elements possibly present in the access transport parameter of the Address Complete
Message (ACM) are transferred into the PSTN XML body (as defined in ES 283 003 [3]) of the 183 Session Progress
sent to the calling user.
For a speech call upon receipt of one of the following messages, if the I-MGCF supports the P-Early-Media header as a
network option, and if the I-MGCF has received the P-Early-Media header in the INVITE request, and has not already
sent a provisional response including a P-Early-Media header with parameters indicating authorization of early media,
then the I-MGCF shall send the 183 Session Progress response with a P-Early-Media header authorizing early media:
- ACM with the value of the called party's status indicator "no indication" and one of the options described in
table 7a1. Based on local configuration, the I-MGCF may also send a 183 Session Progress response with a
P-Early-Media header authorizing early media if it receives an ACM with other parameters than described in
table 7a1.

I-MGCF
ACM
183 Progress
(No indication)
P-Early-Media
appropriate announcement

Figure 7c: Receipt of ACM "No indication"
Table 7a.1: ACM Parameters that trigger the 183 Session Progress response
←183 Session Progress ←ACM

1 ）Optional backward call indicators parameter
183 Session Progress response including a P-Early-Media
In-band information indicator
header authorizing early media, if not already sent
 1 In-band info.
2 ）Backward call indicators parameter
ISDN User Part indicator
0 ISDN User Part not used all the way

NOTE: As a network option the I-MGCF can also map ACM into 183 in other cases than those described in
table 7a1.
ETSI

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