ITS 21/15-ISUP / Report ITS 12 – Prestudy report
Edition 1Page 1

PSTN-ISDN-PLMN ISUP Signalling interface for SWEDEN - technical prestudy

A technical prestudy report for national interconnections between public telecommunications networks (of both public land mobile networks and fixed public telecommunications networks).

Contents

Introduction......

1 Normative references......

2 Structure of ISUP specifications......

3 Scope of ISUP specifications......

3.1 Relationship between ISUP versions......

3.2 ITU-T/ETSI procedures of services that will be supported on the interconnection interface......

Annex 1 – Functions that may impact the PSTN-ISDN-PLMN ISUP Signalling interface for SWEDEN......

A.1Introduction......

A.2 Normative references......

A.3 Swedish unique functions......

A.3.1Transit carrier information......

A.3.2Cell id......

A.3.3Free NDC-values......

A.3.4Priority......

A.3.5Accounting information......

A.3.6Fictitious A-number......

Introduction

This Prestudy report describes the scope of the work performed in the AG 15 ISUP work group. The AG 15 ISUP work group defines the ISUP protocol that shall be used between public telecommunications networks for national interconnections in Sweden. The AG 15 ISUP group shall also specify an ISUP interconnect test specification for the national interconnections.

The ISUP specification has a technical direction. It is assumed that the concerned public telecommunication operator sign mutual commercial agreements on the interconnection, traffic cases, services, traffic volumes, accounting procedures, prices etc. The extent to which the ISUP specification shall be applied will be settled in the agreements. The telecommunications operators can agree on deviations from the ISUP specification.

The ISUP test specification has a technical direction. The applicable sections in the ISUP test specification has to be selected based on the mutual agreements made for the ISUP interface. Each operator has to select which sections of the ISUP test specification that are applicable for their interconnection interface.

1Normative references

The following normative documents contain provisions, which, through reference in this text, constitute provisions of this Prestudy report. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Prestudy report are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies

ITU-T Rec. Q.730 / ISDN User Part supplementary services
ITU-T Rec. Q.731 / Stage 3 description for numbering identification supplementary services using Signalling System No. 7
ITU-T Rec. Q.732 / Stage 3 description for call offering supplementary services using Signalling System No. 7
ITU-T Rec. Q.733 / Stage 3 description for call completion supplementary services using No. 7 Signalling System
ITU-T Rec. Q.734 / Stage 3 description for multiparty supplementary services using Signalling System No. 7
ITU-T Rec. Q.735 / Stage 3 description for community of interest supplementary services using SS No. 7
ITU-T Rec. Q.736 / Stage 3 description for charging supplementary services using Signalling System No. 7
ITU-T Rec. Q.737 / Stage 3 description for additional information transfer supplementary services using Signalling System No. 7
ITU-T Rec. Q.761 / Signalling System No.7 – ISDN user part functional description
ITU-T Rec. Q.762 / Signalling System No. 7 – ISDN user part general functions of messages and signals
ITU-T Rec. Q.763 / Signalling System No. 7 – ISDN user part formats and codes
ITU-T Rec. Q.764 / Signalling System No. 7 – ISDN user part signalling procedures
ITU-T Rec. Q.850 / Usage of cause and location in the Digital Subscriber Signalling System No. 1 and the Signalling System No. 7 ISDN User Part
ETSI EN 300 356-1—20 / ISDN User Part (ISUP) version 3 for the international interface
Telia 8211-A325, rev A / ISDN-PLMN (GSM) signalling interface for Sweden
Telia 8211-A330, rev A / Sending of called party number for calls with network prefixes 95xx to and from Telia’s Swedish fixed network
Telia 8211-A335, rev C / ISDN-ISDN signalling interface for Sweden
Telia 8211-A340, rev A / Specification of the Route identity information (RIN) parameter
Report ITS 9 / Transfer of subscriber number information in national interconnection
ETSI EN 302 097, v1.1.2 / Enhancements for support of Number Portability
ETSI TR 101 xxx, v1.1.1 / Non-circuit related signalling functionality for Number Portability
ETSI TR 102 081,v1.1.1 / Signalling requirement for number portability
Report from ”IT-företag” / Accounting principles
ETSI ES 201 296, v1.1.2 / Signalling aspects of charging
ETSI EN 301 062-1, v1.2.2 / Support of VPN
ETSI EN 301 069-1, v1.2.2 / APM – Application transport mechanism
PN/CSI-98:265, version 1.1 / Krav och beskrivning av valt alternativ för prioritetsnät i Sverige
The European Telecommunications Platform (ETP), framework interconnection agreement: Guidelines for operation & maintenance
98/C 339/04 / Telecommunications: open network provision OPN list of standards (sixth issue)
SS 63 63 90:1999, issue 1 / Number Portability in Sweden – Network solutions for Service Provider Portability for fixed public telecommunications services

2Structure of ISUP specifications

The ISUP specification will be describes as a delta document towards the ITU-T recommendations for ISUP 2000[1] (Q.761-764, Q.850 and Q.730-737). Additions to the ITU-T recommendations will be included. The additions could either be based on ETSI standards or Swedish national requirements.

The ISUP test specification will be described in a separate document. The test specification will only handle ”positive” test cases; it will not handle any negative test. The aim with the test specification is to provide a document that provides enough test cases to secure safe interconnection. All possible ISUP procedures and traffic cases will not be tested. The test specification will focus on the basic procedures to allow minimum functionality on the interface.

3Scope of ISUP specifications

The development of Swedish ISUP is based on the previous Telia ISUP (8211-A335) with alignment with the latest ITU-T/ETSI developments. The functionality of the Swedish ISUP will be higher than the functionality provided by ETSI v2.

Swedish requirements that may affect the ISUP specification are listed in Annex 1

Note: Swedish ISUP is the ISUP that will be developed based on ITU-T ISUP 2000. Telia ISUP is the existing interconnection ISUP (8211-A335) based on Q.767 and ISUP´92.

3.1Relationship between ISUP versions

ITU-T ISUP / ETSI ISUP / Swedish ISUP
Blue Book (1988) / - / -
Q.767 (1990) / ETS 300 121 – ETSI v1 (identical as Q.767) / Telia ISUP – Telia 8211-A335 rev B (Telia ISUP) with additions from SS 63 63 90:1999 issue 1 and Call Forwarding supplementary service from ISUP’92.
Telia ISUP – Telia 8211-A335 rev C (ISDN-ISDN and Telia 8211-A325 rev A (ISDN-PLMN (GSM))
ISUP’92 (1993) / ETS 300 356 – ETSI v2 (based on ISUP’92 with freephone, CCBS and ECT) / -
ISUP’97 (1997) / EN 300 356 – ETSI v3 / -
ISUP 2000 (2000) / ETSI v4 / Swedish ISUP – based on ISUP 2000 and ETSI v3

3.2ITU-T/ETSI procedures of services that will be supported on the interconnection interface

Function/service / National use / Inter-national / ETSI v3 / Swedish ISUP / Telia ISUP
Basic call
Speech/3.1 kHz audio / / / / / / / / / /
64 kbit/s unrestricted / / / / / / / / / /
Multirate connection types (Note) / / / / / / / / / –
N  64 kbit/s connection types / / / / / – / – / –
En bloc address signalling / / / / / / / / / /
Overlap address signalling / / / / / / / / / –
Transit network selection / / / – / – / – / –
Continuity check / / / / / / / / / /
Forward transfer / – / / / / / – / –
Simple segmentation / / / / / / / / / –
Tones and announcements / / / / / / / / / /
Access delivery information / / / / / / / / / –
Transportation of User teleservice information / / / / / / / / / –
Suspend and resume / / / / / / / / / /
Signalling procedures for connection type allowing fallback capability / / / / / / / – / –
Propagation delay determination procedure / / / / / / / – / –
Enhanced echo control signalling procedures / / / / / / / – / –
Simplified echo control signalling procedures / / / / / / / / / /
Automatic repeat attempt / / / / / / / / / /
Blocking and unblocking of circuits and circuit groups / / / / / / / / / /
Circuit group query / / / – / – / – / –
Dual seizure / / / / / / / / / /
Transmission alarm handling for digital inter-exchange circuits / / / / / / / / / /
Reset of circuits and circuit groups / / / / / / / / / /
Receipt of unreasonable signalling information / / / / / / / / / /
Compatibility procedure / / / / / / / / / /
Temporary trunk blocking / / / – / – / – / –
ISDN User Part signalling congestion control / / / / / / / / / –
/represents ITU-T/ETSI/Sweden support.
–represents ITU-T/ETSI/Sweden non-support.
Function/service / National use / Inter-national / ETSI v3 / Swedish ISUP / Telia ISUP
Automatic congestion control / / / / / / / / / –
Interaction between N-ISUP and INAP / / / / / / / / / –
Unequipped circuit identification code / / / – / – / – / –
ISDN User Part availability control / / / / / / / – / –
MTP pause and resume / / / / / / / / / /
Overlength messages / / / / / / / / / /
Temporary Alternative Routing (TAR) / / / / / / / – / –
Hop counter procedure / / / / / / / / / –
Collect call request procedure / / / / / / / / / –
Hard-to-Reach / / / / / – / – / –
Calling Geodetic location procedure / / / / / – / / / –
NOTE – Multirate connection types are 2 × 64, 384, 1536 and 1920 kbit/s.
/represents ITU-T/ETSI/Sweden support.
–represents ITU-T/ETSI/Sweden non-support.
Function/service / National use / Inter-national / ETSI v3 / Swedish ISUP / Telia ISUP
Generic signalling procedures for supplementary services
End-to-end signalling – Pass along method / / / – / – / – / –
End-to-end signalling – SCCP Connection Orientated / / / / / – / – / –
End-to-end signalling – SCCP Connectionless / / / – / – / – / –
Generic number transfer / / / / / / / / / –
Generic digit transfer / / / – / – / / / –
Generic notification procedure / / / / / / / / / /
Service activation / / / / / / / / / –
Remote Operations Service (ROSE) capability / / / – / – / – / –
Network specific facilities / / / – / – / / / –
Pre-release information transport / / / / / / / / / –
Application Transport Mechanism (APM) / / / / / / / / / –
Redirection / / / – / – / – / –
Pivot Routing / / / / / – / – / –
/represents ITU-T/ETSI/Sweden support.
–represents ITU-T/ETSI/Sweden non-support.
Function/service / National use / Inter-national / ETSI v3 / Swedish ISUP / Telia ISUP
Supplementary services
Direct-Dialling-In (DDI) / / / / / / / / / /
Multiple Subscriber Number (MSN) / / / / / / / / / /
Calling Line Identification Presentation (CLIP) / / / / / / / / / /
Calling Line Identification Restriction (CLIR) / / / / / / / / / /
Connected Line Identification Presentation (COLP) / / / / / / / / / /
Connected Line Identification Restriction (COLR) / / / / / / / / / /
Malicious Call Identification (MCID) / / / / / / / / / –
Sub-addressing (SUB) / / / / / / / / / /
Call Forwarding Busy (CFB) / / / / / / / / / /
Call Forwarding No Reply (CFNR) / / / / / / / / / /
Call Forwarding Unconditional (CFU) / / / / / / / / / /
Call Deflection (CD) / / / / / / / / / /
Explicit Call Transfer (ECT) / / / / / / / / / –
Call Waiting (CW) / / / / / / / / / /
Call HOLD (HOLD) / / / / / / / / / /
Completion of Calls to Busy Subscriber (CCBS) / / / / / / / / / –
Completion of Calls on No Reply (CCNR) / / / / / / / / / –
Terminal Portability (TP) / / / / / / / / / /
Conference calling (CONF) / / / / / / / / / /
Three-Party Service (3PTY) / / / / / / / / / /
Closed User Group (CUG) / / / / / / / / / /
Multi-Level Precedence and Preemption (MLPP) / / / / / – / – / –
Global Virtual Network Service (GVNS) / / / / / Note 1 / – / –
International telecommunication charge card (ITCC) / / / / / – / – / –
Reverse charging (REV) / / / – / – / – / –
User-to-User Signalling (UUS) / / / / / / / / / Note 2
Support of VPN applications with PSS1 Information flow / / / / / / / / / –
Support of Number Portability (NP) / / / / / – / / / –
/represents ITU-T/ETSI/Sweden support.
–represents ITU-T/ETSI/Sweden non-support.

Note 1 - GVNS is not supported as an ETSI service, but the ITU-T parameters can still be used in conjunction with Core INAP CS2.

Note 2 – Only UUS service 1 implicit is supported.

Annex 1 – Functions that may impact the PSTN-ISDN-PLMN ISUP Signalling interface for SWEDEN

A.1Introduction

This annex describes the Swedish unique functions identified during the prestudy that may have impact on the scope of the work performed in the AG 15 ISUP work group.

A.2Normative references

The following normative documents contain provisions, which, through reference in this text, constitute provisions of this Prestudy report. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Prestudy report are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to apply.

Telerådet, arbetsgrupp Nummerportabilitet, Subgrupp Avräkning (rapport från IT-företag)
A/B-nummergruppen
PN/CSI-98:265 / Krav och beskrivning av valt alterantiv för prioritetsnät i Sverige

A.3Swedish unique functions

This chapter describes the unique Swedish functions that could affect the ISUP specification work in AG 15 ISUP work team.

A.3.1Transit carrier information

This function introduces a new carrier selection information in ISUP.

During the prestudy this requirement was withdrawn and is therefore not included in the Swedish standard.

A.3.2Cell id

This function is introduced to allow a correct routing of calls to SOS-centrals according to SOS Alarm AB requirements.

This requirement is fulfilled with the introduction of the Calling Geodetic location parameter in the ISUP protocol.

A.3.3Free NDC-values

Introduction of new functions in ISUP that makes it possible to remove allocated NDCs for different services/routing functions or other technical functions that today are used in the Swedish numbering plan for telephony (E.164).

This removal of different NDCs for technical functions makes it possible for a more easy change of the numbering plan structure in the future.

This is a requirement from PTS (National Post & Telecom Agency).

During the prestudy no alternative method to the existing use of B-numbers was identified. Therefore no changes to the protocol are made.

A.3.4Priority

PTS has decided that it shall be possible to allow special users to have priority for their telephone calls in the public telecommunications networks. This function is utilised by using an existing value in Calling party’s Categories (subscriber with priority).

A.3.5Accounting information

To allow a correct handling of accounting between operators it is foreseen that a new indicator both in the forward and in the backward direction is need. No solution is proposed yet.

In the forward direction four alternatives are foreseen:

  • Location number
  • New value in nature of address (in calling party number), this could have a conflict with Calling line identification services.
  • Charged party identification
  • New parameter (e.g. route identification number)

This requires that a numbering plan (or some sort operator identification) is established for all operators. It is possible that an already existing numbering plan can be used.

In the backward direction two alternatives are foreseen:

  • New parameter
  • An All Call Query network handle the accounting (OR network buys the accounting function together with ACQ)

The indicator in the backward direction is only needed if Onward Routing is used.

The team suggest that Location number is used as a short term solution to carry information in the forward direction. When backward information is needed the APM-mechanism should be used to carry information both in the backward and forward direction.

A.3.6Fictitious A-number

A/B-number team in AG 15 is investigating how fictitious A-numbers transported and identified in the public telecommunications network. This could be solved either by a new indicator in nature of address field or as a prefix. Method is not chosen yet.

[1] To be approved at the next ITU-T SG 11 meeting 22 of November to the 10 of December 1999