V5 - UK PSTN MAPPING REQUIREMENTS

Transcription

1 NICC Document ND1703:1998/07 ND1703:1998/07 V5 - UK PSTN MAPPING REQUIREMENTS Protocol Implementation Conformance Statement (PICS) proforma Network Interoperability Consultative Committee Ofcom Riverside House, 2a Southwark Bridge Road, London SE1 9HA UK

2 NICC Document ND1703:1998/07 Normative Information 1998 Crown Copyright NOTICE OF COPYRIGHT AND LIABILITY Copyright All right, title and interest in this document are owned by the Crown and/or the contributors to the document unless otherwise indicated (where copyright be owned or shared with a third party). Such title and interest is protected by United Kingdom copyright laws and international treaty provisions. The contents of the document are believed to be accurate at the time of publishing, but no representation or warranty is given as to their accuracy, completeness or correctness. You may freely download, copy, store or distribute this document provided it is not modified in any way and it includes this copyright and liability statement. You may not modify the contents of this document. You may produce a derived copyright work based on this document provided that you clearly indicate that it was created by yourself and that it was derived from this document and provided further that you ensure that any risk of confusion with this document is avoided. Liability Whilst every care has been taken in the preparation and publication of this document, NICC, nor any committee acting on behalf of NICC, nor any member of any of those committees, nor the companies they represent, nor any person contributing to the contents of this document (together the Generators ) accepts liability for any loss, which may arise from reliance on the information contained in this document or any errors or omissions, typographical or otherwise in the contents. Nothing in this document constitutes advice. Nor does the transmission, downloading or sending of this document create any contractual relationship. In particular no licence is granted under any intellectual property right (including trade and service mark rights) save for the above licence to copy, store and distribute this document and to produce derived copyright works. The liability and responsibility for implementations based on this document rests with the implementer, and not with any of the Generators. If you implement any of the contents of this document, you agree to indemnify and hold harmless the Generators in any jurisdiction against any claims and legal proceedings alleging that the use of the contents by you or on your behalf infringes any legal right of any of the Generators or any third party. None of the Generators accepts any liability whatsoever for any direct, indirect or consequential loss or damage arising in any way from any use of or reliance on the contents of this document for any purpose. If you have any comments concerning the accuracy of the contents of this document, please write to: The Technical Secretary, Network Interoperability Consultative Committee, Ofcom, Riverside House, 2a Southwark Bridge Road, London, SE1 9HA, UK.

3 NICC Document ND1703:1998/07 SSPE SPECIFICATION NUMBER V5 - UK PSTN MAPPING REQUIREMENTS Protocol Implementation Conformance Statement (PICS) proforma ISSUE 2 NETWORK INTER-OPERABILITY CONSULTATIVE COMMITTEE Office of Telecommunications 50 Ludgate Hill London EC4M 7JJ

4 PAGE 2 of 102 Contents 0.1 Normative Information History References Glossary of Terms Abbreviations Definitions INTRODUCTION PICS PROFORMA Identification of the Implementation Implementation Under Test (IUT) Identification System Under Test (SUT) Identification Product Supplier Client PICS Contact Person PICS/System Conformance Statement (SCS) Identification of the Protocol Global Statement of Conformance Local Exchange Summary DEL Main Optional Features PSTN Protocol Protocol Data Units Messages Information Elements: General Information Elements: Pulse Types Information Elements: Steady Signals Error Handling Message/Information Element Summary Messages From AN Messages To AN LOOP CALLING PBX Main Optional Features PSTN Protocol Protocol Data Units Messages Information Elements: General Information Elements: Pulse Types Information Elements: Steady Signals Error Handling Message/Information Element Summary Messages From AN Messages To AN EARTH CALLING PBX Main Optional Features PSTN Protocol Protocol Data Units Messages Information Elements: General Information Elements: Pulse Types Information Elements: Steady Signals... 33

5 PAGE 3 of Error Handling Message/Information Element Summary Messages From AN Messages To AN DDI PBX Main Optional Features PSTN Protocol Protocol Data Units Messages Information Elements: General Information Elements: Pulse Types Information Elements: Steady Signals Error Handling Message/Information Element Summary Messages From AN Messages To AN Access Network Summary DEL Main Optional Features Analogue Line Signals PSTN Protocol Protocol Data Units Messages Information Elements General Information Elements: Pulse Types Information Elements: Steady Signals Error Handling Autonomous Actions Message/Information Element Summary Messages From LE Messages To LE LOOP CALLING PBX Main Optional Features Analogue Line Signals PSTN Protocol Protocol Data Units Messages Information Elements General Information Elements: Pulse Types Information Elements: Steady Signals Error Handling Autonomous Actions Message/Information Element Summary Messages From LE Messages To LE EARTH CALLING PBX Main Optional Features Analogue Line Signals PSTN Protocol Protocol Data Units Messages Information Elements General Information Elements: Pulse Types Information Elements: Steady Signals Error Handling... 72

6 PAGE 4 of Autonomous Actions Message/Information Element Summary Messages From LE Messages To LE DDI PBX Main Optional Features Analogue Line Signals PSTN Protocol Protocol Data Units Messages Information Elements General Information Elements: Pulse Types Information Elements: Steady Signals Error Handling Autonomous Actions Message/Information Element Summary Messages From LE Messages To LE Annex A (Informative): Instructions for Completing the PICS Proforma A.1 Identification of the Implementation A.2 Global Statement of Conformance A.3 Summary A.4 Main Optional Features A.5 Analogue Signals A.6 Protocol A.7 Protocol Data Units A.8 Message/Information Element Summary A.9 Message Sequence Charts Annex B (Informative): Common Characteristics B.1 Ring Cadence/V5 Cadenced Ringing Type B.2 Initial Ring Pulse Duration Type Definitions B.3 Pulse Reduced Battery Pulse Duration Type Definitions B.4 Pulsed No Battery Pulse Duration Type Definitions B.5 Recognition Time Duration Types Annex C (Informative): DEL Specific Characteristics C.1 Electrical Characteristics of Analogue Signals C.2 DEL Message Sequence Charts Annex D (Informative): Loop Calling PBX Specific Characteristics D.1 Electrical Characteristics of Analogue Signals D.2 Loop Calling PBX Message Sequence Charts Annex E (Informative): Earth Calling PBX Specific Characteristics E.1 Electrical Characteristics of Analogue Signals E.1 Earth Calling PBX Message Sequence Charts Annex F (Informative): DDI Specific Characteristics F.1 Electrical Characteristics of Analogue Signals F.1 Sequence Charts DDI Message

7 PAGE 5 of 102 Normative Information History (c) 1998 Oftel [Office of Telecommunications] NOTICE OF COPYRIGHT AND LIABILITY: All right, title and interest in this document are owned by the Director General of Telecommunications and are protected by United Kingdom copyright laws and international treaty provisions. You may freely copy or distribute this document as long as: i) It is not modified in any way; and, ii) It includes this copyright and liability statement. Whilst every care has been taken in the preparation and publication of this document, errors in content, typographical or otherwise, may occur. If you have any comments concerning its accuracy, please write to: Oftel [Office of Telecommunications], 50 Ludgate Hill, London, EC4V 7JJ. The liability and responsibility for implementations based on this document rests with the implementor, and not with Oftel. Issue 1.0, July, , July , July 1998 Via NICC Web site In order to place of this specification on the public area of the NICC Website the following amendment was made to the above notice of copyright and liability. In the first line Oftel was replaced by the Director General of Telecommunications. The date and issue number remain the same.

8 PAGE 6 of 102 References SSPE/SPEC/001-1, Issue 1: V5 - UK PSTN Mapping Requirements [2] ETS , February 1994 Signalling Protocols and Switching (SPS); V interfaces at the digital Local Exchange (LE); V5.1 interface for the support of Access Network (AN); Part 1: V5.1 interface specification as amended by ETS , Amendment A1 [3] ETS , February 1994: Signalling Protocols and Switching (SPS) V interfaces at the digital Local Exchange (LE); V5.1 interface for the support of Access Network (AN); Part 2: Protocol Implementation Conformance Statement (PICS) proforma [4] ISO/IEC : Information technology - Open systems interconnection Conformance testing methodology and framework - Part 1: General Concepts [5] ISO/IEC : Information technology - Open systems interconnection Conformance testing methodology and framework - Part 7: Implementation Conformance Systems [6] ETS , September 1994 Signalling Protocols and Switching (SPS); V interfaces at the digital Local Exchange (LE); V5.2 interface for the support of Access Network (AN); Part 1: V5.2 interface specification as amended by ETS , Amendment pra1 Glossary of Terms Abbreviations ACK Acknowledge signal AN Access Network C7 (NUP) CCITT Signalling System Number 7 National User Part CCITT International Telegraph and Telephone Consultative Committee CLASS Custom Local Area Signalling Services CPE Customers Premises Equipment CSH Called Subscriber Hold DEL Direct Exchange Line DCPI Disconnect Clear Primitive Indicator DDI Direct Dial In EOC End Of Call

9 PAGE 7 of 102 ETS European Telecommunications Standard ETSI European Telecommunications Standards Institute FE Function Element I/C Incoming IEC International Electrotechnical Commission ISO International Standards Organisation IUT Implementation Under Test LE Local Exchange M Mandatory MCI Malicious Call Indication MF Multiple Frequency MSC Message Sequence Chart O Optional OSI Open Systems Interface Not Applicable PBX Private Branch Exchange PICS Protocol Implementation Conformance Statement PSTN Public Switched Telephone Network Q(AN) Q interface at the AN Q(LE) Q interface at the LE SCS System Conformance Statement SDL Specification and Description Language SPM Subscribers Private Meter SUT System Under Test TE Terminal Equipment TMN Telecommunications Management Network UK United Kingdom of Great Britain & Northern Ireland V5 A generic term for an ETSI interface family used to connect ANs to an LE. V5.1 An interface conforming to ETS [2] V5.2 An interface conforming to ETS [6] Definitions AN Access Network - A system implemented between the Local Exchange (LE) and user, replacing part or the whole of the local line distribution network. Analogue Port The physical port implementation in the AN to provide the relevant interface functions towards the user. The analogue port is addressed by a logical address used in the relevant protocols on the V5 interface. CPE Any equipment that can be connected to a user port and is located at the customer premises such as a telephone or small call routing apparatus.

10 PAGE 8 of 102 LE Local Exchange - An exchange on which user lines may be terminated via an AN. PICS Protocol Implementation Conformance Statement, a document made by the supplier of an Open Systems Interconnection (OSI) implementation or system, stating which capabilities have been implemented for a given OSI protocol (see ISO/IEC [4]). PICS proforma A document, in the form of a questionnaire, designed by the committee specifying the protocol or conformance test suite, which, when completed for an OSI implementation or system, becomes the PICS (see ISO/IEC [4]). Pre- Defined A parameter is said to be Pre-defined when it is not required to be configured via the management (TMN) interface. Instead, the parameter is either intrinsically provided within the equipment or is provided on installation or re-equipping of the equipment via a local interface. Provisioned A parameter is said to be provisioned if it can be configured via the management (TMN) interface. Such an interface may be Q3 conformant or proprietary. Static conformance review A review of the extent to which the static conformance requirements are met by the Implementation Under Test (IUT), accomplished by comparing the PICS with the static conformance requirements expressed in the relevant standard(s) (see ISO/IEC [4]). User port The physical port implemented in the AN to provide the relevant interface functions towards the user. The user port is addressed by a logical address used in the relevant protocols on the V5 interface.

11 PAGE 9 of 102 INTRODUCTION This section defines the Protocol Implementation Conformance Statement (PICS) proforma for the implementation flexibility allowed for the PSTN portion of a V5 interface defined in ETS [2] and SSPE/SPEC/ PICS can be used by: the Network Operator for the formulation of PSTN requirements for V5 implementation in an Access Network (AN) or a Local Exchange (LE). the Network Operator for determining whether a specific implementation meets the V5 requirements of that Network Operator s PSTN. suppliers for publishing their products degree of compliance with the standards. suppliers for developing a V5 design for the UK market. It details, in tabular form, the implementation options, i.e. the optional functions additional to those which are mandatory to implement. This specification is in compliance with the relevant requirements and in accordance with the relevant guidance given in ISO/IEC [5]. This document is intended to be used in association with the ETS PICS [3] and assumes that the reader is familiar with the interpretation of PICS as used by ETSI. The details regarding the use and interpretation of this document are specified in Annex A. Notwithstanding the provisions of the copyright Clause related to the text of this document, permission is granted that users may freely reproduce the PICS proforma in clause 2 and Annex A through and including Annex F, so that it can be used for its intended purposes and may further publish the completed PICS.

12 PAGE 10 of 102 PICS PROFORMA Identification of the Implementation Implementation Under Test (IUT) Identification IUT Name: IUT Version: System Under Test (SUT) Identification SUT Name: Hardware Configuration: Operating System: Product Supplier Name: Address: Telephone: Facsimile: Miscellaneous:

13 PAGE 11 of 102 Client Name: Address: Telephone: Facsimile: Miscellaneous: PICS Contact Person Name: Telephone: Facsimile: Miscellaneous:

14 PAGE 12 of 102 PICS/System Conformance Statement (SCS) Provide the relationship of the PICS with the SCS for the system: Identification of the Protocol This PICS proforma applies to the following standards: SSPE/SPEC/ Global Statement of Conformance The implementation described in this PICS meets all mandatory requirements of the referenced standard. [ ] Yes [ ] No NOTE: Answering No to this question indicates a non-conformance to the protocol specification. Non-supported mandatory capabilities are to be identified in the PICS, with an explanation of why the implementation is non-conforming.

15 PAGE 13 of 102 Local Exchange Summary Line Type Basic Service SPM 30 kω Hook Flash MX.2.1 DEL MX.2.2 Loop PBX MX.2.3 Earth Calling MX.2.4 DDI DEL Main Optional Features Conditions for status Status Reference F1 SPM? O F2 30kΩ Loop? O F3 Hook Flash? O PSTN Protocol Conditions for status Status Reference PP1 Equivalent functionality to that specified for the following when considered from the external interface [D]: M Call Control Process? & 5.3 National PSTN Protocol Process? LE_PSTN Protocol Process? 3.1.5

16 PAGE 14 of 102 Protocol Data Units Within ETS [3] the status of some Protocol Data Unit items is shown as being conditional on MX.2, which the ETS states is provided by the national specification. In the case of the UK, the status of those items conditional on MX.2 is provided in the clauses below. Messages Conditions for status Status Reference U1.9 PROTOCOL PARAMETER? O Information Elements: General Conditions for status Status Reference U1.12 Pulse Notification? U1.35 OR U1.36 OR F1 NOT (U1.35 OR U1.36 OR F1) U1.13 Line Information? F2 NOT F2 O M [ ] [ ] U1.15 Autonomous Signalling Sequence? U1.16 Sequence Response? U1.22 Recognition Time? U1.9 NOT U1.9 M [ ] U1.23 Enable Autonomous Acknowledge? U1.24 Disable Autonomous Acknowledge?

17 PAGE 15 of 102 Information Elements: Pulse Types Conditions for status Status Reference U1.30 pulse type: Pulsed normal polarity? U1.31 pulse type: Pulsed reversed polarity? U1.32 pulse type: Pulsed battery on c-wire? U1.33 pulse type: Pulsed on hook? U1.34 pulse type: Pulsed reduced battery? O U1.35 pulse type: Pulsed no battery? O U1.36 pulse type: Initial ring? O U1.37 pulse type: Meter pulse? F1 NOT F1 M [ ] U1.38 pulse type: 50 Hz pulse? U1.39 pulse type: Register recall? F3 NOT F3 M [ ] U1.40 pulse type: Pulsed off hook? U1.41 pulse type: Pulsed b-wire connected to earth? U1.42 pulse type: Earth loop pulse? U1.43 pulse type: Pulsed b-wire connected to battery? U1.44 pulse type: Pulsed a-wire connected to earth? U1.45 pulse type: Pulsed a-wire connected to battery? U1.46 pulse type: Pulsed c-wire connected to earth? U1.47 pulse type: Pulsed c-wire disconnected? U1.48 pulse type: Pulsed normal battery? U1.49 pulse type: Pulsed a-wire disconnected? U1.50 pulse type: Pulsed b-wire disconnected?

18 PAGE 16 of 102 U1.91 suppression indicator? U1.34 OR U1.35 OR U1.36 OR F1 NOT (U1.34 OR U1.35 OR U1.36 OR F1) U1.92 acknowledge request indicator? U1.36 NOT U1.36 AND (U1.35 OR F1) NOT (U1.36 AND (U1.35 OR F1)) M M O [ ] [ ] U1.93 suppression indicator? U1.94 acknowledge request indicator? U1.95 digit acknowledge request indicator? M

19 PAGE 17 of 102 Information Elements: Steady Signals Conditions for status Status Reference U1.51 Steady signal: Normal polarity? O U1.52 Steady signal: Reversed polarity? O U1.53 Steady signal: Battery on c-wire? U1.54 Steady signal: No battery on c-wire? U1.55 Steady signal: Off hook? M U1.56 Steady signal: On hook? M U1.57 Steady signal: Battery on a-wire? U1.58 Steady signal: A-wire on earth? U1.59 Steady signal: No battery on a-wire? U1.60 Steady signal: No battery on b-wire? U1.61 Steady signal: Reduced battery? O U1.62 Steady signal: No battery? U1.63 Steady signal: Alternate reduced power/no power? U1.64 Steady signal: Normal Battery? U1.65 Steady signal: Stop ringing? U1.66 Steady signal: Start pilot frequency? U1.67 Steady signal: Stop pilot frequency? U1.68 Steady signal: Low impedance on b- wire? U1.69 Steady signal: B-wire connected to earth? U1.70 Steady signal: B-wire disconnected from earth? U1.71 Steady signal: Normal battery on b- wire? U1.72 Steady signal: Low loop impedance? U1.73 Steady signal: High loop impedance? U1.74 Steady signal: Anomalous loop impedance? U1.75 Steady signal: A-wire disconnected from earth? U1.76 Steady signal: C-wire on earth? U1.77 Steady signal: C-wire disconnected from earth?

20 PAGE 18 of 102 Error Handling Conditions for status Status Reference EH1 Unrecognised Information Elements? M EH2 IE Content Error? M

21 PAGE 19 of 102 Message/Information Element Summary Messages From AN First of 3 tables - Messages from AN Message IE None Digit Signal Resource Unavailable Line Information Cadenced Ringing Recognition Time Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Second of 3 tables - Messages from AN IE Pulse Notification Pulsed Signal Message Pulsed Reduced Battery Pulsed No Battery Initial Ring Meter Pulse Register Recall Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Message Third of 3 Tables - Messages from AN IE Normal Polarity Reversed Polarity Steady Signal Off Hook On Hook Reduced Battery Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter

22 PAGE 20 of 102 Messages To AN First of 3 tables - Messages to AN Message IE None Digit Signal Resource Unavailable Line Information Cadenced Ringing Recognition Time Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Message Second of 3 tables - Messages to AN IE Pulse Notification Pulsed Reduced Battery Pulsed No Battery Pulsed Signal Initial Ring Meter Pulse Register Establish Establish Ack Signal Disconnect Recall Disconnect Complete Protocol Parameter Third of 3 tables - Messages to AN IE Steady Signal Normal Reversed Off Hook On Hook Reduced Battery Message Polarity Polarity Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter

23 PAGE 21 of 102 LOOP CALLING PBX Main Optional Features Conditions for status Status Reference F1 SPM? O F2 30kΩ Loop? O F3 Hook Flash? O PSTN Protocol Conditions for status Status Reference PP1 Equivalent functionality to that specified for the following when considered from the external interface [D]: M Call Control Process? & 6.3 National PSTN Protocol Process? LE_PSTN Protocol Process? 3.1.5

24 PAGE 22 of 102 Protocol Data Units Within ETS [3] the status of some Protocol Data Unit items is shown as being conditional on MX.2, which the ETS states is provided by the national specification. In the case of the UK, the status of those items conditional on MX.2 is provided in the clauses below. Messages Conditions for status Status Reference U1.9 PROTOCOL PARAMETER? O Information Elements: General Conditions for status Status Reference U1.12 Pulse Notification? U1.35 OR U1.36 OR F1 NOT (U1.35 OR U1.36 OR F1) U1.13 Line Information? F2 NOT F2 O M ] [ ] U1.15 Autonomous Signalling Sequence? U1.16 Sequence Response? U1.22 Recognition Time? U1.9 NOT U1.9 M [ ] U1.23 Enable Autonomous Acknowledge? U1.24 Disable Autonomous Acknowledge?

25 PAGE 23 of 102 Information Elements: Pulse Types Conditions for status Status Reference U1.30 pulse type: Pulsed normal polarity? U1.31 pulse type: Pulsed reversed polarity? U1.32 pulse type: Pulsed battery on c-wire? U1.33 pulse type: Pulsed on hook? U1.34 pulse type: Pulsed reduced battery? U1.35 pulse type: Pulsed no battery? O U1.36 pulse type: Initial ring? O U1.37 pulse type: Meter pulse? F1 NOT F1 M [ ] U1.38 pulse type: 50 Hz pulse? U1.39 pulse type: Register recall? F3 NOT F3 M [ ] U1.40 pulse type: Pulsed off hook? U1.41 pulse type: Pulsed b-wire connected to earth? U1.42 pulse type: Earth loop pulse? U1.43 pulse type: Pulsed b-wire connected to battery? U1.44 pulse type: Pulsed a-wire connected to earth? U1.45 pulse type: Pulsed a-wire connected to battery? U1.46 pulse type: Pulsed c-wire connected to earth? U1.47 pulse type: Pulsed c-wire disconnected? U1.48 pulse type: Pulsed normal battery? U1.49 pulse type: Pulsed a-wire disconnected? U1.50 pulse type: Pulsed b-wire disconnected?

26 PAGE 24 of 102 U1.91 suppression indicator? U1.35 OR U1.36 OR F1 NOT (U1.35 OR U1.36 OR F1) U1.92 acknowledge request indicator? U1.36 NOT U1.36 AND (U1.35 OR F1) NOT (U1.36 AND (U1.35 OR F1)) M M O [ ] [ ] U1.93 suppression indicator? U1.94 acknowledge request indicator? U1.95 digit acknowledge request indicator? M

27 PAGE 25 of 102 Information Elements: Steady Signals Conditions for status Status Reference U1.51 Steady signal: Normal polarity? O U1.52 Steady signal: Reversed polarity? O U1.53 Steady signal: Battery on c-wire? U1.54 Steady signal: No battery on c-wire? U1.55 Steady signal: Off hook? M U1.56 Steady signal: On hook? M U1.57 Steady signal: Battery on a-wire? U1.58 Steady signal: A-wire on earth? U1.59 Steady signal: No battery on a-wire? U1.60 Steady signal: No battery on b-wire? U1.61 Steady signal: Reduced battery? O U1.62 Steady signal: No battery? U1.63 Steady signal: Alternate reduced power/no power? U1.64 Steady signal: Normal Battery? U1.65 Steady signal: Stop ringing? U1.66 Steady signal: Start pilot frequency? U1.67 Steady signal: Stop pilot frequency? U1.68 Steady signal: Low impedance on b- wire? U1.69 Steady signal: B-wire connected to earth? U1.70 Steady signal: B-wire disconnected from earth? U1.71 Steady signal: Normal battery on b- wire? U1.72 Steady signal: Low loop impedance? U1.73 Steady signal: High loop impedance? U1.74 Steady signal: Anomalous loop impedance? U1.75 Steady signal: A-wire disconnected from earth? U1.76 Steady signal: C-wire on earth? U1.77 Steady signal: C-wire disconnected from earth?

28 PAGE 26 of 102 Error Handling Conditions for status Status Reference EH1 Unrecognised Information Elements? M EH2 IE Content Error? M

29 PAGE 27 of 102 Message/Information Element Summary Messages From AN First of 3 tables - Messages from AN Message IE None Digit Signal Resource Unavailable Line Information Cadenced Ringing Recognition Time Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Second of 3 tables - Messages from AN IE Pulse Notification Pulsed Signal Message Pulsed No Battery Initial Ring Meter Pulse Register Recall Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Third of 3 Tables - Messages from AN IE Steady Signal Normal Reversed Off Hook On Hook Reduced Message Polarity Polarity Battery Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter

30 PAGE 28 of 102 Messages To AN First of 3 tables - Messages to AN Message IE None Digit Signal Resource Unavailable Line Information Cadenced Ringing Recognition Time Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Second of 3 tables - Messages to AN IE Pulse Notification Pulsed Signal Message Pulsed No Battery Initial Ring Meter Pulse Register Recall Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Third of 3 tables - Messages to AN IE Steady Signal Message Normal Polarity Reversed Polarity Off Hook On Hook Reduced Battery Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter

31 PAGE 29 of 102 EARTH CALLING PBX Main Optional Features Conditions for status Status Reference F1 SPM? O F2 30kΩ Loop? O F3 Hook Flash? O PSTN Protocol Conditions for status Status Reference PP1 Equivalent functionality to that specified for the following when considered from the external interface [D]: M Call Control Process? & 7.3 National PSTN Protocol Process? LE_PSTN Protocol Process? 3.1.5

32 PAGE 30 of 102 Protocol Data Units Within ETS [3] the status of some Protocol Data Unit items is shown as being conditional on MX.2, which the ETS states is provided by the national specification. In the case of the UK, the status of those items conditional on MX.2 is provided in the clauses below. Messages Conditions for status Status Reference U1.9 PROTOCOL PARAMETER? Information Elements: General Conditions for status Status Reference U1.12 Pulse Notification? U1.35 OR F1 NOT (U1.35 OR F1) U1.13 Line Information? F2 NOT F2 O M [ ] [ ] U1.15 Autonomous Signalling Sequence? U1.16 Sequence Response? U1.22 Recognition Time? U1.23 Enable Autonomous Acknowledge? U1.24 Disable Autonomous Acknowledge?

33 PAGE 31 of 102 Information Elements: Pulse Types Conditions for status Status Reference U1.30 pulse type: Pulsed normal polarity? U1.31 pulse type: Pulsed reversed polarity? U1.32 pulse type: Pulsed battery on c-wire? U1.33 pulse type: Pulsed on hook? U1.34 pulse type: Pulsed reduced battery? U1.35 pulse type: Pulsed no battery? O U1.36 pulse type: Initial ring? U1.37 pulse type: Meter pulse? F1 NOT F1 M [ ] U1.38 pulse type: 50 Hz pulse? U1.39 pulse type: Register recall? F3 NOT F3 M [ ] U1.40 pulse type: Pulsed off hook? U1.41 pulse type: Pulsed b-wire connected to earth? U1.42 pulse type: Earth loop pulse? U1.43 pulse type: Pulsed b-wire connected to battery? U1.44 pulse type: Pulsed a-wire connected to earth? U1.45 pulse type: Pulsed a-wire connected to battery? U1.46 pulse type: Pulsed c-wire connected to earth? U1.47 pulse type: Pulsed c-wire disconnected? U1.48 pulse type: Pulsed normal battery? U1.49 pulse type: Pulsed a-wire disconnected? U1.50 pulse type: Pulsed b-wire disconnected?

34 PAGE 32 of 102 U1.91 suppression indicator? U1.35 OR F1 NOT (U1.35 OR F1) U1.92 acknowledge request indicator? U1.35 OR F1 NOT (U1.35 OR F1) M O [ ] [ ] U1.93 suppression indicator? U1.94 acknowledge request indicator? U1.95 digit acknowledge request indicator? M

35 PAGE 33 of 102 Information Elements: Steady Signals Conditions for status Status Reference U1.51 Steady signal: Normal polarity? O U1.52 Steady signal: Reversed polarity? O U1.53 Steady signal: Battery on c-wire? U1.54 Steady signal: No battery on c-wire? U1.55 Steady signal: Off hook? M U1.56 Steady signal: On hook? M U1.57 Steady signal: Battery on a-wire? U1.58 Steady signal: A-wire on earth? U1.59 Steady signal: No battery on a-wire? U1.60 Steady signal: No battery on b-wire? U1.61 Steady signal: Reduced battery? O U1.62 Steady signal: No battery? U1.63 Steady signal: Alternate reduced power/no power? U1.64 Steady signal: Normal Battery? U1.65 Steady signal: Stop ringing? U1.66 Steady signal: Start pilot frequency? U1.67 Steady signal: Stop pilot frequency? U1.68 Steady signal: Low impedance on b- wire? U1.69 Steady signal: B-wire connected to earth? U1.70 Steady signal: B-wire disconnected from earth? U1.71 Steady signal: Normal battery on b- wire? M U1.72 Steady signal: Low loop impedance? U1.73 Steady signal: High loop impedance? U1.74 Steady signal: Anomalous loop impedance? U1.75 Steady signal: A-wire disconnected from earth? U1.76 Steady signal: C-wire on earth? U1.77 Steady signal: C-wire disconnected from earth?

36 PAGE 34 of 102 Error Handling Conditions for status Status Reference EH1 Unrecognised Information Elements? M EH2 IE Content Error? M

37 PAGE 35 of 102 Message/Information Element Summary Messages From AN First of 3 tables - Messages from AN Message IE None Digit Signal Resource Unavailable Line Information Cadenced Ringing Establish Establish Ack Signal Disconnect Disconnect Complete Second of 3 tables - Messages from AN IE Pulse Pulsed Signal Pulsed Meter Pulse Register Message No Battery Recall Establish Establish Ack Signal Disconnect Disconnect Complete Third of 3 Tables - Messages from AN IE Steady Signal Message Normal Polarity Reversed Polarity Off Hook On Hook Reduced Battery B-Wire Connected to Earth Establish Establish Ack Signal Disconnect Disconnect Complete

38 PAGE 36 of 102 Messages To AN First of 3 tables - Messages to AN Message IE None Digit Signal Resource Unavailable Line Information Cadenced Ringing Establish Establish Ack Signal Disconnect Disconnect Complete Second of 3 tables - Messages to AN IE Pulse Notification Pulsed Signal Message Pulsed No Battery Meter Pulse Register Recall Establish Establish Ack Signal Disconnect Disconnect Complete Third of 3 tables - Messages to AN IE Steady Signal Normal Polarity Reversed Off Hook On Hook Reduced B-Wire Message Polarity Battery Connected to Earth Establish Establish Ack Signal Disconnect Disconnect Complete

39 PAGE 37 of 102 DDI PBX Main Optional Features There are no main optional features for the DDI portion of the protocol. PSTN Protocol Conditions for status Status Reference PP1 Equivalent functionality to that specified for the following when considered from the external interface [D]: M Call Control Process? & 8.3 National PSTN Protocol Process? LE_PSTN Protocol Process? 3.1.5

40 PAGE 38 of 102 Protocol Data Units Within ETS [3] the status of some Protocol Data Unit items is shown as being conditional on MX.2, which the ETS states is provided by the national specification. In the case of the UK, the status of those items conditional on MX.2 is provided in the clauses below. Messages Conditions for status Status Reference U1.9 PROTOCOL PARAMETER? Information Elements: General Conditions for status Status Reference U1.12 Pulse Notification? M U1.13 Line Information? U1.15 Autonomous Signalling Sequence? U1.16 Sequence Response? U1.22 Recognition Time? U1.23 Enable Autonomous Acknowledge? U1.24 Disable Autonomous Acknowledge?

41 PAGE 39 of 102 Information Elements: Pulse Types Conditions for status Status Reference U1.30 pulse type: Pulsed normal polarity? U1.31 pulse type: Pulsed reversed polarity? U1.32 pulse type: Pulsed battery on c-wire? U1.33 pulse type: Pulsed on hook? M U1.34 pulse type: Pulsed reduced battery? U1.35 pulse type: Pulsed no battery? U1.36 pulse type: Initial ring? U1.37 pulse type: Meter pulse? U1.38 pulse type: 50 Hz pulse? U1.39 pulse type: Register recall? U1.40 pulse type: Pulsed off hook? U1.41 pulse type: Pulsed b-wire connected to earth? U1.42 pulse type: Earth loop pulse? U1.43 pulse type: Pulsed b-wire connected to battery? U1.44 pulse type: Pulsed a-wire connected to earth? U1.45 pulse type: Pulsed a-wire connected to battery? U1.46 pulse type: Pulsed c-wire connected to earth? U1.47 pulse type: Pulsed c-wire disconnected? U1.48 pulse type: Pulsed normal battery? U1.49 pulse type: Pulsed a-wire disconnected? U1.50 pulse type: Pulsed b-wire disconnected?

42 PAGE 40 of 102 U1.91 suppression indicator? M U1.92 acknowledge request indicator? M U1.93 suppression indicator? U1.94 acknowledge request indicator? U1.95 digit acknowledge request indicator? M

43 PAGE 41 of 102 Information Elements: Steady Signals Conditions for status Status Reference U1.51 Steady signal: Normal polarity? M U1.52 Steady signal: Reversed polarity? M U1.53 Steady signal: Battery on c-wire? U1.54 Steady signal: No battery on c-wire? U1.55 Steady signal: Off hook? M U1.56 Steady signal: On hook? U1.57 Steady signal: Battery on a-wire? U1.58 Steady signal: A-wire on earth? U1.59 Steady signal: No battery on a-wire? U1.60 Steady signal: No battery on b-wire? U1.61 Steady signal: Reduced battery? U1.62 Steady signal: No battery? M U1.63 Steady signal: Alternate reduced power/no power? U1.64 Steady signal: Normal Battery? U1.65 Steady signal: Stop ringing? U1.66 Steady signal: Start pilot frequency? U1.67 Steady signal: Stop pilot frequency? U1.68 Steady signal: Low impedance on b- wire? U1.69 Steady signal: B-wire connected to earth? U1.70 Steady signal: B-wire disconnected from earth? U1.71 Steady signal: Normal battery on b- wire? U1.72 Steady signal: Low loop impedance? U1.73 Steady signal: High loop impedance? U1.74 Steady signal: Anomalous loop impedance? U1.75 Steady signal: A-wire disconnected from earth? U1.76 Steady signal: C-wire on earth? U1.77 Steady signal: C-wire disconnected from earth?

44 PAGE 42 of 102 Error Handling Conditions for status Status Reference EH1 Unrecognised Information Elements? M EH2 IE Content Error? M

45 PAGE 43 of 102 Message/Information Element Summary Messages From AN First of 2 tables - Messages from AN IE None Digit Signal Resource Unavailable Pulse Notification Pulsed Signal Message Pulsed On Hook Establish Establish Ack Signal Disconnect Disconnect Complete Second of 2 Tables - Messages from AN IE Steady Signal Normal Reversed Off Hook No Battery Message Polarity Polarity Establish Establish Ack Signal Disconnect Disconnect Complete

46 PAGE 44 of 102 Messages To AN First of 2 tables - Messages to AN IE None Digit Signal Resource Unavailable Pulse Notification Pulsed Signal Message Pulsed On Hook Establish Establish Ack Signal Disconnect Disconnect Complete Second of 2 tables - Messages to AN IE Steady Signal Message Normal Polarity Reversed Polarity Off Hook No Battery Establish Establish Ack Signal Disconnect Disconnect Complete

47 PAGE 45 of 102 Access Network Summary Line Type Basic Service SPM 30 kω Hook Flash MX.2.1 DEL Basic Call MX.2.2 Loop PBX MX.2.3 Earth Calling MX.2.4 DDI DEL Main Optional Features Conditions for status Status Reference F1 SPM? O F2 30 kω Loop? O F3 Hook Flash? O 5.2.1

48 PAGE 46 of 102 Analogue Line Signals Does the implementation support.. Conditions for status Status Reference ASD1 ON-HOOK? M ASD2 OFF-HOOK? M ASD3 30 kω LOOP? F2 NOT F2 M [ ] ASD4 DIGITS? M ASD5 REGISTER RECALL? M ASD6 NORMAL POWER FEED? M ASD7 REVERSED POWER FEED? M ASD8 END OF CALL? M ASD9 DISCONNECT CLEAR? M ASD10 PARKED LINE FEED? M ASD11 CALL ARRIVAL INDICATION? M ASD12 INITIAL RING? M ASD13 SPM? F1 NOT F1 ASD14 HOOK FLASH? F3 NOT F3 M M [ ] [ ] PSTN Protocol Conditions for status Status Reference PP1 Equivalent functionality to that specified for the following, when considered from the external interfaces [A and D]: M Analogue Port Process? & 5.2 AN_PSTN User Port Process? AN_PSTN Protocol Process? 3.1.3

49 PAGE 47 of 102 Protocol Data Units Within ETS the status of some Protocol Data Unit items is shown as being conditional on MX.2 which the ETS states is provided by the national specification. In the case of the UK, the status of those items conditional on MX.2 is provided in the clauses below. Messages Conditions for status Status Reference U1.9 PROTOCOL PARAMETER? M Information Elements General Conditions for status Status Reference U1.12 Pulse Notification? M U1.13 Line Information? F2 NOT F2 M [ ] U1.15 Autonomous Signalling Sequence? U1.16 Sequence Response? U1.22 Recognition Time? U1.9 M U1.23 Enable Autonomous Acknowledge? U1.24 Disable Autonomous Acknowledge?

50 PAGE 48 of 102 Information Elements: Pulse Types Conditions for status Status Reference U1.30 pulse type: Pulsed normal polarity? U1.31 pulse type: Pulsed reversed polarity? U1.32 pulse type: Pulsed battery on c-wire? U1.33 pulse type: Pulsed on hook? U1.34 pulse type: Pulsed reduced battery? M U1.35 pulse type: Pulsed no battery? M U1.36 pulse type: Initial ring? M U1.37 pulse type: Meter pulse? F1 NOT F1 M [ ] U1.38 pulse type: 50 Hz pulse? U1.39 pulse type: Register recall? F3 NOT F3 M [ ] U1.40 pulse type: Pulsed off hook? U1.41 pulse type: Pulsed b-wire connected to earth? U1.42 pulse type: Earth loop pulse? U1.43 pulse type: Pulsed b-wire connected to battery? U1.44 pulse type: Pulsed a-wire connected to earth? U1.45 pulse type: Pulsed a-wire connected to battery? U1.46 pulse type: Pulsed c-wire connected to earth? U1.47 pulse type: Pulsed c-wire disconnected? U1.48 pulse type: Pulsed normal battery? U1.49 pulse type: Pulsed a-wire disconnected? U1.50 pulse type: Pulsed b-wire disconnected?

51 PAGE 49 of 102 U1.91 suppression indicator? M U1.92 acknowledge request indicator? M U1.93 suppression indicator? U1.94 acknowledge request indicator? U1.95 digit acknowledge request indicator? M

52 PAGE 50 of 102 Information Elements: Steady Signals Conditions for status Status Reference U1.51 Steady signal: Normal polarity? M U1.52 Steady signal: Reversed polarity? M U1.53 Steady signal: Battery on c-wire? U1.54 Steady signal: No battery on c-wire? U1.55 Steady signal: Off hook? M U1.56 Steady signal: On hook? M U1.57 Steady signal: Battery on a-wire? U1.58 Steady signal: A-wire on earth? U1.59 Steady signal: No battery on a-wire? U1.60 Steady signal: No battery on b-wire? U1.61 Steady signal: Reduced battery? M U1.62 Steady signal: No battery? U1.63 Steady signal: Alternate reduced power/no power? U1.64 Steady signal: Normal Battery? U1.65 Steady signal: Stop ringing? U1.66 Steady signal: Start pilot frequency? U1.67 Steady signal: Stop pilot frequency? U1.68 Steady signal: Low impedance on b-wire? U1.69 Steady signal: B-wire connected to earth? U1.70 Steady signal: B-wire disconnected from earth? U1.71 Steady signal: Normal battery on b-wire? U1.72 Steady signal: Low loop impedance? U1.73 Steady signal: High loop impedance? U1.74 Steady signal: Anomalous loop impedance? U1.75 Steady signal: A-wire disconnected from earth? U1.76 Steady signal: C-wire on earth? U1.77 Steady signal: C-wire disconnected from earth?

53 PAGE 51 of 102 Error Handling Conditions for status Status Reference EH1 Unrecognised Information Elements? M EH2 IE Content Error? M

54 PAGE 52 of 102 Autonomous Actions Conditions for status Status Reference AAD1 AAD2.1 AAD2.2 AAD3 AAD4 AAD5 AAD6.1 AAD6.2 AAD6.3 AAD7 Whilst a Pulsed Signal is being applied - Receipt of a line or control primitive? Whilst a Pulsed Signal is being applied - Receipt of a management primitive : storage? Whilst a Pulsed Signal is being applied - Receipt of a management primitive : truncation? Whilst a Pulsed Signal is being applied - Receipt of External Analogue Signal? Whilst a Pulsed Signal is being applied - Receipt of New Incoming Call? Completion / truncation of Pulsed Signal: DISCONNECT CLEAR? Completion / truncation of Pulsed Signal: END OF CALL - apply NORMAL POWER FEED? Completion / truncation of Pulsed Signal: END OF CALL - Reapply steady signal? Completion / truncation of Pulsed Signal: Any other pulsed signal? Completion / truncation of Pulsed Signal: Stored primitives? M O (a) O (b) M M M (a) O (b) (I) O (b) (II) M (c) M AAD8 Receipt of call finished : DCPI = Received? M AAD9 AAD10 Receipt of call finished : DCPI = Not Received? Receipt of call finished : DCPI = Not Received; CPE applying ON-HOOK; Send DISCONNECT CLEAR M O (a) (II) AAD11 Receipt of Restart Mgmt Primitive : DCPI = Received? AAD12 Receipt of Restart Mgmt Primitive : DCPI = Not Received? AAD13 Receipt of Restart Mgmt Primitive : DCPI = Not Received; CPE applying ON-HOOK; Send DISCONNECT CLEAR? M M O (a) (II)

55 PAGE 53 of 102 AAD14 Receipt of Block Mgmt Primitive : DCPI = Received? AAD15 Receipt of Block Mgmt Primitive : DCPI = Not Received? AAD16 Receipt of Block Mgmt Primitive : DCPI = Not Received; CPE applying ON-HOOK; Send DISCONNECT CLEAR? M M O (a) (I) AAD17 Receipt of DIGITS in any valid state? M AAD18 Receipt of OFF-HOOK during application of CALL ARRIVAL INDICATION? M AAD19 Receipt of External 30kΩ Signal? F2 NOT F2 M [ ] AAD20 Receipt of Steady Signal? M AAD21 Receipt of call arrival indication? M AAD22 Additional AN resources required? M AAD23 AAD24 Receipt of Unblock whilst port is blocked? Receipt of REGISTER RECALL or HOOK FLASH while awaiting LE ack.? M M AAD25 Setting of DCPI? M AAD26 Receipt of Unrecognised Primitives? M AAD27 Receipt of Unexpected Primitives? M O.1 = of at least one of these items is required, while only one can be active. O.2 = of at least one of these items is required, while only one can be active.

56 PAGE 54 of 102 Message/Information Element Summary Messages From LE First of 3 tables - Messages from LE Message IE None Digit Signal Resource Unavailable Line Information Cadenced Ringing Recognition Time Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Second of 3 tables - Messages from LE IE Pulse Notification Pulsed Signal Pulsed Reduced Pulsed No Battery Initial Ring Meter Pulse Register Recall Message Battery Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Third of 3 tables - Messages from LE IE Steady Signal Message Normal Reversed Off Hook On Hook Reduced Polarity Polarity Battery Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter

57 PAGE 55 of 102 Messages To LE First of 3 tables - Messages to LE Message IE None Digit Signal Resource Unavailable Line Information Cadenced Ringing Recognition Time Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Second of 3 tables - Messages to LE IE Pulse Notification Pulsed Signal Pulsed Reduced Pulsed No Battery Initial Ring Meter Pulse Register Recall Message Battery Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter Third of 3 Tables - Messages to LE IE Steady Signal Normal Reversed Off Hook On Hook Reduced Message Polarity Polarity Battery Establish Establish Ack Signal Disconnect Disconnect Complete Protocol Parameter

58 PAGE 56 of 102 LOOP CALLING PBX Main Optional Features Conditions for status Status Reference F1 SPM? O F2 30 kω Loop? O F3 Hook Flash? O 6.2.1

59 PAGE 57 of 102 Analogue Line Signals Does the implementation support.. Conditions for status Status Reference ASL1 ON-HOOK? M ASL2 OFF-HOOK? M ASL3 30 kω LOOP? F2 NOT F2 M [ ] ASL4 DIGITS? M ASL5 REGISTER RECALL? M ASL6 NORMAL POWER FEED? M ASL7 REVERSED POWER FEED? M ASL8 DISCONNECT CLEAR? M ASL9 PARKED LINE FEED? M ASL10 CALL ARRIVAL INDICATION? M ASL11 INITIAL RING? M ASL12 SPM? F1 NOT F1 ASL13 HOOK FLASH? F3 NOT F3 M M [ ] [ ] PSTN Protocol Conditions for status Status Reference PP1 Equivalent functionality to that specified for the following, when considered from the external interfaces [A and D]: M Analogue Port Process? & 6.2 AN_PSTN User Port Process? AN_PSTN Protocol Process? 3.1.3

60 PAGE 58 of 102 Protocol Data Units Within ETS the status of some Protocol Data Unit items is shown as being conditional on MX.2 which the ETS states is provided by the national specification. In the case of the UK, the status of those items conditional on MX.2 is provided in the clauses below. Messages Conditions for status Status Reference U1.9 PROTOCOL PARAMETER? M Information Elements General Conditions for status Status Reference U1.12 Pulse Notification? M U1.13 Line Information? F2 NOT F2 M [ ] U1.15 Autonomous Signalling Sequence? U1.16 Sequence Response? U1.22 Recognition Time? U1.9 M U1.23 Enable Autonomous Acknowledge? U1.24 Disable Autonomous Acknowledge?

61 PAGE 59 of 102 Information Elements: Pulse Types Conditions for status Status Reference U1.30 pulse type: Pulsed normal polarity? U1.31 pulse type: Pulsed reversed polarity? U1.32 pulse type: Pulsed battery on c-wire? U1.33 pulse type: Pulsed on hook? U1.34 pulse type: Pulsed reduced battery? U1.35 pulse type: Pulsed no battery? M U1.36 pulse type: Initial ring? M U1.37 pulse type: Meter pulse? F1 NOT F1 M [ ] U1.38 pulse type: 50 Hz pulse? U1.39 pulse type: Register recall? F3 NOT F3 M [ ] U1.40 pulse type: Pulsed off hook? U1.41 pulse type: Pulsed b-wire connected to earth? U1.42 pulse type: Earth loop pulse? U1.43 pulse type: Pulsed b-wire connected to battery? U1.44 pulse type: Pulsed a-wire connected to earth? U1.45 pulse type: Pulsed a-wire connected to battery? U1.46 pulse type: Pulsed c-wire connected to earth? U1.47 pulse type: Pulsed c-wire disconnected? U1.48 pulse type: Pulsed normal battery? U1.49 pulse type: Pulsed a-wire disconnected? U1.50 pulse type: Pulsed b-wire disconnected?

62 PAGE 60 of 102 U1.91 suppression indicator? M U1.92 acknowledge request indicator? M U1.93 suppression indicator? U1.94 acknowledge request indicator? U1.95 digit acknowledge request indicator? M

63 PAGE 61 of 102 Information Elements: Steady Signals Conditions for status Status Reference U1.51 Steady signal: Normal polarity? M U1.52 Steady signal: Reversed polarity? M U1.53 Steady signal: Battery on c-wire? U1.54 Steady signal: No battery on c-wire? U1.55 Steady signal: Off hook? M U1.56 Steady signal: On hook? M U1.57 Steady signal: Battery on a-wire? U1.58 Steady signal: A-wire on earth? U1.59 Steady signal: No battery on a-wire? U1.60 Steady signal: No battery on b-wire? U1.61 Steady signal: Reduced battery? M U1.62 Steady signal: No battery? U1.63 Steady signal: Alternate reduced power/no power? U1.64 Steady signal: Normal Battery? U1.65 Steady signal: Stop ringing? U1.66 Steady signal: Start pilot frequency? U1.67 Steady signal: Stop pilot frequency? U1.68 Steady signal: Low impedance on b-wire? U1.69 Steady signal: B-wire connected to earth? U1.70 Steady signal: B-wire disconnected from earth? U1.71 Steady signal: Normal battery on b-wire? U1.72 Steady signal: Low loop impedance? U1.73 Steady signal: High loop impedance? U1.74 Steady signal: Anomalous loop impedance? U1.75 Steady signal: A-wire disconnected from earth? U1.76 Steady signal: C-wire on earth? U1.77 Steady signal: C-wire disconnected from earth?