Welltech SS7 User Manual
Dialogic® SS7 Protocols
ISUP Programmer's Manual
www.dialogic.com
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Publication Date:
Document Number: U04SSS, Issue 15
2
February 2008
Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
Contents
Revision History............................................................................................................7
1 About this Publication .........................................................................................9
1.1 Introduction...........................................................................................................................9
1.2 Abbreviations......................................................................................................................... 9
1.3 Related Documentation ......................................................................................................... 10
1.4 Feature Overview ................................................................................................................. 11
2 General Description...........................................................................................13
2.1 Module Overview..................................................................................................................13
2.2 Module Configuration ............................................................................................................ 13
2.2.1 Customizing ISUP variants......................................................................................... 14
3 Internal Data Structures ...................................................................................17
3.1 Introduction......................................................................................................................... 17
3.2 Global Ram Data Structure .................................................................................................... 17
3.3 Circuit Group Data Structure.................................................................................................. 17
3.4 Per Circuit Data Structure...................................................................................................... 17
4 Interface to System Services.............................................................................19
4.1 System Functions ................................................................................................................. 19
4.2 Timer Operation ................................................................................................................... 19
5 Interface to MTP................................................................................................21
6 Interface to Application.....................................................................................23
6.1 Introduction......................................................................................................................... 23
6.2 Application Message - Header Format...................................................................................... 23
6.2.1 Transmit Request ..................................................................................................... 23
6.2.2 Receive Indication .................................................................................................... 24
6.3 Application Message - User Data Format .................................................................................. 25
6.4 Parameter Extension Mechanism ............................................................................................ 26
6.5 Application Messages to ISUP................................................................................................. 26
6.5.1 Alerting Request....................................................................................................... 28
6.5.2 Application Transport Request.................................................................................... 30
6.5.3 ‘Generic’ Charge Request .......................................................................................... 31
6.5.4 Circuit Seized Request .............................................................................................. 31
6.5.5 Collection Charging Request ...................................................................................... 32
6.5.6 Confusion Request.................................................................................................... 32
6.5.7 Continuity Request ................................................................................................... 32
6.5.8 End-to-End Message Request..................................................................................... 33
6.5.9 Exit Request .......................................................................................................... 33
6.5.10 Facility Request........................................................................................................ 33
6.5.11 Facility Response...................................................................................................... 35
6.5.12 Forward Transfer Request.......................................................................................... 36
6.5.13 Identification Request ............................................................................................... 36
6.5.14 Identification Response ............................................................................................. 36
6.5.15 Information Request................................................................................................. 37
6.5.16 Loop Back Acknowledgement Request......................................................................... 38
6.5.17 Loop Prevention Request........................................................................................... 39
6.5.18 Network Resource Management Request ..................................................................... 39
6.5.19 Overload Request..................................................................................................... 40
6.5.20 Pre-Release Information Request ............................................................................... 40
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Contents
6.5.21 Proceeding request ...................................................................................................41
6.5.22 Progress Request...................................................................................................... 42
6.5.23 Release Response..................................................................................................... 43
6.5.24 Release Request....................................................................................................... 44
6.5.25 Request Information Request .....................................................................................45
6.5.26 Resume Request....................................................................................................... 45
6.5.27 Segmentation Request ..............................................................................................46
6.5.28 Setup Request..........................................................................................................46
6.5.29 Setup Response .......................................................................................................49
6.5.30 Subsequent Directory Number Request ....................................................................... 52
6.5.31 Suspend Request...................................................................................................... 52
6.5.32 Unrecognised Message Request.................................................................................. 53
6.5.33 User Information Request.......................................................................................... 53
6.6 Application Messages from ISUP ............................................................................................. 54
6.6.1 Alerting Indication .................................................................................................... 56
6.6.2 Application Transport Indication ................................................................................. 59
6.6.3 ‘Generic’ Charge Indication ........................................................................................59
6.6.4 Circuit Seized Indication............................................................................................60
6.6.5 Collection Charging Indication....................................................................................60
6.6.6 Confusion Indication ................................................................................................. 60
6.6.7 Continuity Indication.................................................................................................61
6.6.8 End-to-End Message Indication ..................................................................................61
6.6.9 Exit Indication..........................................................................................................61
6.6.10 Facility Indication ..................................................................................................... 62
6.6.11 Facility Confirmation ................................................................................................. 63
6.6.12 Forward Transfer Indication .......................................................................................64
6.6.13 Identification Indication............................................................................................. 64
6.6.14 Identification Confirmation.........................................................................................65
6.6.15 Information Indication............................................................................................... 65
6.6.16 Loop Back Acknowledgement Indication ...................................................................... 66
6.6.17 Loop Prevention Indication.........................................................................................67
6.6.18 Network Resource Management Indication................................................................... 67
6.6.19 Overload Indication...................................................................................................68
6.6.20 Pre-Release Information Indication .............................................................................68
6.6.21 Proceeding Indication................................................................................................ 69
6.6.22 Progress Indication................................................................................................... 70
6.6.23 Release Confirmation ................................................................................................ 71
6.6.24 Release Indication .................................................................................................... 71
6.6.25 Request Information Indication .................................................................................. 72
6.6.26 Resume Indication....................................................................................................73
6.6.27 Segmentation Indication............................................................................................ 73
6.6.28 Setup Confirmation...................................................................................................74
6.6.29 Setup Indication.......................................................................................................76
6.6.30 Subsequent Directory Number Indication.....................................................................78
6.6.31 Suspend Indication ...................................................................................................79
6.6.32 Unrecognised Message Indication ............................................................................... 79
6.6.33 User Information Indication ....................................................................................... 79
6.7 Parameter Definitions............................................................................................................ 80
6.7.1 Called Party Number .................................................................................................86
6.7.2 Calling Party Number ................................................................................................86
6.7.3 Cause Indicators.......................................................................................................87
6.7.4 Custom Parameter....................................................................................................88
6.7.5 Message Data ..........................................................................................................88
6.7.6 Number of Metering Pulses ........................................................................................89
6.7.7 Tariff Type ..........................................................................................................89
6.7.8 Unrecognised Parameter............................................................................................90
6.8 Use of Call Control Primitives..................................................................................................90
6.8.1 Call Clearing Procedure .............................................................................................90
6.8.2 Call Collision Procedure ............................................................................................. 91
6.8.3 Hop Counter Procedure ............................................................................................. 94
6.8.4 Continuity Testing..................................................................................................... 95
6.8.5 Malicious Call Identification (MCID) Supplementary Service ......................................... 108
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DialogicTP®TP SS7 Protocols ISUP Programmer's Manual Issue 15
6.8.6 Message Segmentation ........................................................................................... 109
6.8.7 Automatic Circuit Group Blocking ............................................................................. 109
6.8.8 BICC Application Transport...................................................................................... 111
7 Management Interface ....................................................................................113
7.1 Introduction....................................................................................................................... 113
7.2 Circuit Group Supervision Control Request............................................................................. 114
7.3 Circuit Group Supervision Control Confirmation ...................................................................... 115
7.4 Circuit Group Supervision Control Indication .......................................................................... 116
7.5 Circuit Group Supervision Status Indication............................................................................ 117
7.6 Local Overload Request ....................................................................................................... 118
7.7 Remote Point Code Status Indication..................................................................................... 119
8 Non-Primitive Interface...................................................................................121
8.1 Configure Request .............................................................................................................. 121
8.2 Configure Circuit Group Request........................................................................................... 126
8.3 Configure Timers Request.................................................................................................... 136
8.3.1 Timer default values ............................................................................................... 138
8.4 End Circuit Group Request ................................................................................................... 140
8.5 Variant Initialisation............................................................................................................ 141
8.6 Custom Parameter Configuration .......................................................................................... 142
8.7 Change Circuit Group Configuration Request .......................................................................... 143
8.8 Read RAM Request.............................................................................................................. 145
8.9 Read Circuit Group Request ................................................................................................. 145
8.10 Read Circuit Request........................................................................................................... 146
8.11 Read Revision Request ........................................................................................................ 146
8.12 Read Circuit Group Status Request ....................................................................................... 147
8.13 Read Circuit Group Data Request.......................................................................................... 150
8.14 Read Circuit Group Identity Request ..................................................................................... 151
8.15 Send Maintenance Event Mask Request ................................................................................. 152
8.16 Send Software Event Mask Request ...................................................................................... 153
8.17 Trace Mask Configuration Request ........................................................................................ 154
8.18 Send Selective Trace Event Mask Request.............................................................................. 157
8.19 Maintenance Event Indication............................................................................................... 158
8.20 Software Event Indication.................................................................................................... 162
8.21 Management Event Indication .............................................................................................. 165
8.22 Trace Event Indication......................................................................................................... 166
8.23 Selective Trace Event Indication ........................................................................................... 167
8.24 Heartbeat Request/Indication............................................................................................... 169
Appendix A: ISUP National Variants .........................................................................171
A.1 German ISUP..................................................................................................................... 171
A.2 UK ISUP ............................................................................................................................ 172
A.3 Japan (TTC) ISUP ............................................................................................................... 173
A.4 Nortel RLT ......................................................................................................................... 174
A.4.1 Nortel RLT (ANSI)................................................................................................... 174
A.4.2 Nortel RLT (ITU)..................................................................................................... 175
A.5 Italian ISUP ....................................................................................................................... 176
A.6 French ISUP....................................................................................................................... 177
A.7 China ISUP ........................................................................................................................ 178
A.8 Finnish ISUP ...................................................................................................................... 180
A.9 BICC................................................................................................................................. 180
Appendix B: Messages Currently Supported by the ISUP Module..............................183
B.1 ITU-T Messages.................................................................................................................. 183
B.2 ITU-T Parameters............................................................................................................... 184
B.3 ANSI T1.113 Messages........................................................................................................ 188
B.4 ANSI T1.113 Parameters ..................................................................................................... 189
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Contents
Appendix C: Message Type Table..............................................................................191
Appendix D: ISUP Configuration Option Settings......................................................193
Appendix E: ISUP Repeat Parameters.......................................................................197
Appendix F: Timer Services ......................................................................................199
F.1 Keep Time ......................................................................................................................... 199
F.1 Timer Expiry ...................................................................................................................... 200
Index .............................................................................................................201
Figures
Figure 1. Notation used for Parameter Specifications ................................................................. 85
Figure 2. Format of the Called Party Number Parameter.............................................................86
Figure 3. Format of the Calling Party Number Parameter............................................................ 86
Figure 4. Format of the Cause Indicators Parameter ..................................................................87
Figure 5. Format of the Custom Parameter...............................................................................88
Figure 6. Format of the Message Data Parameter ......................................................................88
Figure 7. Format of the Number of Metering Pulses Parameter.................................................... 89
Figure 8. Format of the Tariff Parameter .................................................................................. 89
Figure 9. Format of the Unrecognised Parameter.......................................................................90
Figure 10. Example of an External Call Collision where this End of the Circuit is Master....................92
Figure 11. Example of an External Call Collision where this end of the Circuit is Slave...................... 93
Figure 12. Example of an Internal Call Collision .......................................................................... 93
Figure 13. Example of a Successful Continuity Check Request Message Received............................96
Figure 14. Example of a Continuity Check Request Message Received (Unsuccessful Continuity Check
followed by Successful Continuity Check).................................................................... 97
Figure 15. Example of a Successful Continuity Check Received During Incoming Call Set Up ............98
Figure 16. Example of an Unsuccessful Continuity Check Received During Incoming Call Set Up .......99
Figure 17. Example of a Continuity Check Request Message Received (ANSI)...............................100
Figure 18. Example of a T36 Expiry......................................................................................... 101
Figure 19. Example of a Successful Continuity Check Request Message Sent ................................ 103
Figure 20. Example of a Continuity Check Request Message Sent (Unsuccessful Continuity Check
Followed By Successful Continuity Check) ................................................................. 104
Figure 21. Example of a Continuity Check Success Outgoing Call Set Up...................................... 105
Figure 22. Example of a Continuity Check Success during Outgoing Call Set Up............................ 106
Figure 23. Example of a Call collision where the Incoming Call has Priority ................................... 107
Figure 24. Example of a Reset Circuit Received During a Continuity Test Call................................ 108
Tables
Table 1. All Application Messages sent by the ISUP Module to the User Application....................... 54
Table 2. Release Cause Values used in the Release indication sent to the Application when Cal l
Processing Timers Expire ..........................................................................................87
Table 3. ISUP Module Confirmation Message Statuses............................................................. 113
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DialogicTP®TP SS7 Protocols ISUP Programmer's Manual Issue 15
Revision History
Issue Date Description
15 February 2008 Minor alterations to sections 6.5.30 and 6.6.30.
14 January 2008 Rebranded and reformatted, plus minor changes and updates.
13 June 2006 Support for Bearer Independent Call Control (BICC) added.
New messages added: Change Circuit Group Configuration Request, Read Circuit
Group Data Request and Read Circuit Group Identity Request.
Options ISPF_24PC, ISPF_PC_SIZE and ISPX1GOP_16PC updated.
New module option, ISPF_16CID, added in ISP_MSG_CONFIG to maintain backward
compatibility and support 64k configurations.
Support for tracing of Configuration Request and Heartbeat request messages.
Support for location value in Release cause.
12 July 2003 Branding changed: references to System7 removed. Support for French ISUP, China
11 August 2001 Support for user custom optional parameter.
10 December 1999 Continuity check and circuit seized added.
9 July 1998 Point code length, SIO value, UCIC option and timer values may now be configured on
ISUP, and Finnish ISUP added.
MPM added.
Redirecting parameter now supported in TTC IAM.
Support for MCID supplementary service.
APM and PRI message definitions corrected.
Support for ITU-T 1997.
New software event (15).
New group options for the user part unavailability procedure and selective tracing
added.
New parameter in Configure Circuit Group Request message for hop counter
procedure added.
New timer T4 and T38 added.
New maintenance events for the hop counter procedure and the user part
unavailability procedure added.
New Selective trace event request mask and Selective trace event indication
messages.
Generic CRG message now supported.
Appendix E added.
Editorial changes.
Enhanced remote point code status indication.
Additional circuit states report added in read circuit group status.
New software event added.
ISUP configuration option settings added.
Table of messages added.
Minor editorial changes.
a circuit group basis, allowing both ITU and ANSI circuit groups to be supported at the
same time.
Added new circuit group option to remove ST digit from end of Called party number
sent to network and another circuit group option to add ST digit to end of Called party
number sent to user.
User teleservice information and Freephone indicators parameters are now supported.
Generic number supported in Release message.
Message tracing now supported
New maintenance events added to report invalid group messages received.
7
Revision History
Issue Date Description
8 May 1997 A circuit group may now be ended without having to restart the module. This allows
7 September 1996 Now supports ITU-T 1992 messages and parameters (whilst allowing Blue Book only
6 May 1996 Now supports ANSI operation as a run-time configuration option.
5 April 1996 Call clearing mechanism modified to require a response from the application in all
4 April 1996 Backward call indicators in ANM sent to ISUP module are now optional and if omitted
3 August 1995 New messages added: ISP_MSG_STATUS_IND, ISP_MSG_OVLD_REQ,
2 February 1994
1 September 1993
the application to dynamically configure and end individual circuit groups as required.
The local status of a circuit may now be read. New primitives have been added to
allow enabling and disabling of all maintenance and software events.
New support for Temporary Trunk Blocking procedures (Overload_ind added) and
Charging procedures (Charge_req and Charge_ind added).
New circuit group option for Q.767 formatting of cause parameter.
operation using a run-time configuration option.
Table of supported parameters added.
Optional support for T34 (segmentation), pass-along messages, and message and
parameter compatibility handling added.
New module option to allow reporting of errors in application messages sent to ISUP.
Circuit group configuration message parameter definitions changed to allow the
optional use of 24bit point codes.
cases and to require the application to wait for a Release confirmation from the ISUP
module before commencing a new call.
Use of the most significant bit of the call reference to indicate an outgoing call
removed.
Ability to configure and re-configure all protocol timer values at run-time added.
Additional optional parameters added: Redirection information, Redirection number,
Redirecting Number and Signalling point code.
Optional support for UCIC message and timer T35 added.
Read call request message removed.
This revision of the manual describes the operation of the ISUP protocol module with a
core revision number of V2.00 and later.
ISUP will not insert any default.
Original called number and User service information parameters added to setup
request and setup indication.
Forward transfer message and Call offering message (Italian network only) added.
Support for dual instance of ISUP (ISPF_DUAL) added.
Per-circuit group adjacent module_id’s and instance numbers added to circuit-group
configuration message.
ISP_MSG_CGSS_IND.
Parameters added to user primitives: access transport, user to user information, user
to user indicators
New user primitive types added: Facility_req, Facility_resp, Facility_ind, Facility_conf,
User_info_req, User_info_ind
Circuit group query added to circuit group supervision control request.
Additional circuit group options defined
Note: The latest release issue of this guide can be found at:
http://www.dialogic.com/support/helpweb/signaling
8
Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
About this Publication
1.1 Introduction
The ISUP module is a software implementation of the Signalling System
Number 7, ISDN User Part (ISUP). In addition to supporting major ISUP
variants such as ITU-T recommendations Q.761-Q.764, Q.767, ETSI standard
ETS 300 356-1, and ANSI T1.113 the ISUP module supports national variants
including German ISUP and Japanese TTC ISUP. It is also possible for the
user to customize existing variants by adding or deleting parameters. The
ISUP module supports, as a purchasable option, the BICC (Bearer
Independent Call Control) protocol which is treated as a variant in its own
right.
This document is the Programmer's Manual for the ISUP module. It is
intended for use by users developing their own application programs that will
interface with and use the functionality provided by the ISUP module.
The module uses the services provided by the Message Transfer Part (MTP) to
exchange signaling messages with remote signaling points. It supports a
number of both-way telephony circuits. The circuits can be divided into a
number of circuit groups; each group may be assigned different attributes
allowing the user considerable flexibility in the configuration of the module.
The ISUP module is event driven and uses standard structured messages for
inter-process communication. It is intended to be used in conjunction with
the MTP module either on hardware platforms or on user supplied hardware.
However, the software is portable and the well-defined message structure
and the independent nature of the module allows ISUP to be used with
alternative MTP implementations if required.
This manual gives an overview of the internal operation of the ISUP module
and defines the structure of all messages that can be sent to, or issued by,
the module. It also describes all the configuration parameters.
on page 183 lists the ITU-T ISUP and the ANSI T1.113 ISUP messages and
parameters that are currently supported by the module.
Appendix B
1.2 Abbreviations
ANSI American National Standards Institute
BICC Bearer Independent Call Control
CIC Circuit Identification Code
DPC Destination Point Code
ISDN Integrated Services Digital Network
ISUP ISDN User Part
ITU International Telecommunication Union
MTP Message Transfer Part
OPC Originating Point Code
SS7 Signalling System Number 7
9
Section 1 About this Publication
1.3 Related Documentation
[1] ITU-T recommendation Q.730, ISDN Supplementary services
[2] ITU-T recommendation Q.761, Signalling System No.7 ISDN User
10
part functional description
[3]
[4] ITU-T recommendation Q.763 Signalling System No.7 ISDN User part
[5]
[6] ITU-T recommendation Q.765 (2000), Signalling System No. 7 –
[7] ITU-T recommendation Q.767, Application of the ISDN user part of
[8]
[9] ANSI recommendation T1.113, Signalling System No.7 Integrated
[10]
[11] German ISUP Specification: Zeichengabe im ZZN7 Version 3.0.0
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20] Finnish ISUP Specification: SFS 5779 Signalling in the public switched
[21]
[22]
ITU-T recommendation Q.762, Signalling System No.7 ISDN User
part general functions of messages and signals
format and codes
ITU-T recommendation Q.764, Signalling System No.7 ISDN User
part signalling procedures
Application transport mechanism
CCITT signalling system No. 7 for international ISDN interconnections
ETSI standard 300 356-1, Integrated Services Digital Network
(ISDN); Signalling System No.7
Services Digital Network (ISDN) User Part
UK ISUP Specification: PNO-ISC Specification Number 007 ISDN User
Part (ISUP)
ITU-T recommendation Q.850, Usage of cause and location in the
Digital Subscriber Signalling System No.1 and the Signalling System
No.7 ISDN User Part
Italian ISUP Specification: Specifica Tecnica N.763
Nortel RLT (ANSI) Specification: Digital Switching Systems UCS DMS-
250 SS7 RLT Feature Application Guide UCS12 297-2621-345
Preliminary 04.01 August 1999
Nortel RLT (ITU) Specification: 411- 2131-199 Standard 08.04
August 1998 Wireless Networks DMS-MTX Software Delta for Planners
MTX07
Japan (TTC) ISUP Specification: JT-Q761-JT-Q764 and JT-Q850
U10SSS, Software Environment Programmer's Manual
French ISUP Specification: SPIROU 1998 – 002-005 edition 1
China ISUP Specification: YDN 038 (1997)
telephone network (PSTN). ISDN User Part ISUP Version 2 of the
national Signalling System No. 7. Application of ITU-T
recommendations Q.761. Q.764 and Q.766 in Finland (1994)
ITU-T Recommendation Q.1901, Bearer Independent Call Control
Protocol
ITU-T Recommendation Q.1902.1, Bearer Independent Call Control
protocol (Capability Set 2): Functional description
Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
[23] ITU-T Recommendation Q.1902.2 (2001), Bearer independent Call
Control protocol (CS-2) and Signalling System No. 7 – ISDN User Part
general functions of messages and parameters
[24] ITU-T Q. Recommendation 1902.3 (2001), Bearer i n dependent call
control protocol (CS-2) and signalling system No. 7 – ISDN user part
formats and codes
[25] ITU-T Recommendation Q.1902.4 (2001), Bearer independent call
control protocol (CS-2) basic call procedures
[26]
[27]
ITU-T Recommendation Q.1902.5 (2001), Exception
ITU-T Q.765.5 (2000), Signalling System No. 7 – Application
transport mechanism: Bearer Independent Call Control (2000)
1.4 Feature Overview
Key features of the ISUP module include:
• Software implementation of ITU-T recommendation Q.761-Q.764 (1997).
• Software implementation of ITU-T recommendation Q.767 (1992).
• Software implementation of ETSI standard ETS 300 356-1 (1995).
• Software implementation of ANSI T1.113-1995.
• Software implementation of ITU-T recommendation Q.1901, Q1902.1-
Q.1902.5 (2001).
• Message oriented interface.
• Configuration options on a per-circuit group basis.
• User configuration of all protocol timers.
• Support for both en-bloc and overlap address signaling.
• Support for Suspend and Resume.
• Full user control of Circuit Supervisory functions - Reset, Blocking,
Unblocking and Query.
• Support for circuit group as well as individual circuit supervision
messages.
• Support for supplementary services.
• Built-in generation of Automatic congestion control parameter.
• Ability to add or delete optional parameters to define a custom ISUP
variant.
• Debug tracing of messages exchanged with the user and MTP.
• Ability to send and receive CRG messages for ITU based variants.
11
Section 1 About this Publication
12
Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
2 General Description
2.1 Module Overview
The ISUP module implements full ISDN User Part functionality. This includes
Call Processing Control (CPC), Circuit Supervision Control (CSC) and
Signalling Procedure Control (SPRC) all of which are fully supported. In
addition, the module implements some Call Control functionality to provide a
clean interface with the user that is defined entirely in terms of ISUP
messages.
Each circuit is identified internally by a Circuit Identifier (cid). Circuit
Identifiers range from zero up to one less than the total number of circuits. A
circuit must be assigned to a circuit group before it can be used.
Circuit groups allow a number of circuits to be configured with common
attributes. They are identified by the group identifier (gid) which ranges from
zero to one less than the total number of circuit groups. Each circuit group
must be assigned an Originating Point Code (OPC) and a Destination Point
Code (DPC), the Circuit Identification Code (CIC) of the first circuit in the
group and the Circuit Identifier (cid) that will be used for this circuit. Further
circuits may be included in the group providing that the CIC of the last circuit
is no more than 31 greater than the first CIC. The circuits do not need to lie
in a contiguous block. The Circuit Identifier cid for each additional circuit will
have the same offset from the first cid as the CIC has from the first CIC.
Each circuit group also has a number of options such as Outgoing/Incoming
Call Priority selection and whether the module is the controlling exchange for
certain timers and features.
All protocol primitives between the application and the ISUP module use a
Call Reference (call_ref) to identify the circuit used for the call. The call
reference is identical to the Circuit Identifier (cid) with the exception that for
messages issued by the ISUP module relating to outgoing calls the most
significant bit of the call_ref is set to one when the ISUP module is configured
for 32768 circuits or less, and the ISPF_16CID flag is set to 0. In all other
cases (more than 32768 circuits configured, or ISPF_16CID flag set to 1), the
cid is identical to the call_reference. The ISUP module now ignores the setting
of the most significant bit of the call_ref and it is recommended that existing
applications which placed significance on this bit be modified to ignore it also.
2.2 Module Configuration
The module is configured for operation by the user in three stages. Initially,
a global configuration message must be sent to the module to configure
environment dependent parameters (in general these parameters will be
fixed for any single application).
Then, an optional message to set the values of protocol timers is issued.
Finally, a configuration message is required for each circuit group before
attempting to originate or accept calls.
The variant of ISUP (e.g. ITU-T, ANSI, national variants or BICC) to be used
for circuits in a group is specified by a configuration parameter in the circuit
group configuration message.
13
Section 2 General Description
Depending on the platform that ISUP is running, some or all of these
configuration messages may be generated based on text based configuration
files (config.txt). In such cases the user does not need to generate the
individual configuration messages. Refer to the product documentation for the
specific product for further information.
2.2.1 Customizing ISUP variants
The ISUP module supports a variant-based mechanism that enables the user
to select a custom-reserved variant thus permitting the ISUP module to send
and receive proprietary parameters (in supported ISUP messages only) to
and from the network. The following messages are required for this
mechanism:
• Variant Initialisation message (0x5712)
• Custom Parameter Configuration message (0x5713)
Refer to
details.
The variant-based mechanism may be initialized as follows:
1. Configure the ISUP module using the Configure Request message
2. Two ‘custom’ variant values are specifically reserved for this procedure
Section 8.6 on page 142 and Section 8.7 on page 143 for further
(0x7700) as described in
Section : 2.2 Module Configuration on page 13.
as shown in the following table (refer to the <variant> parameter in
Section : 8.2 Configure Circuit Group Request on pa ge 126):
Value Mnemonic Meaning
0xfd ISPGVAR_CUST02 Custom variant CUST02
0xfe ISPGVAR_CUST01 Custom variant CUST01
Configure a circuit group and select one of the available custom variant
values using the Configure Circuit Group Request message (0x7701).
The Configure Circuit Group Request message may be sent at any stage
after the ISUP module has been configured; it is not necessary to wait
until after the custom variant and parameters have been configured.
3. Initialize a custom variant using the Variant Initialisation message
(0x5712) and specify the ISUP variant e.g. ISPGVAR_ITU92 upon which
the custom variant is based. The Variant Initialisation message may be
sent at any stage after the ISUP module has been configured but it must
be sent before the Custom Parameter Configuration message (described
in the next step).
4. Configure the custom parameter using the Custom Parameter
Configuration message (0x5713). The Custom Parameter Configuration
message may be sent at any stage after the ISUP module has been
configured but it must be sent before the sending and receiving of any
customized parameters.
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Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
The Custom Parameter Configuration message should be sent when a
proprietary parameter is to be added to, or removed from, an existing ISUP
message. A separate Custom Parameter Configuration message is required
and must be sent for each ISUP message to which the proprietary parameter
is to be added, or from which it is to be omitted.
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Section 2 General Description
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Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
3 Internal Data Structures
3.1 Introduction
This chapter describes the internal data structures that are used by the ISUP
module to assist the user in understanding the operation of the module. It is
not necessary to acquire detailed knowledge of these structures in order to
use the module.
3.2 Global Ram Data Structure
The entire data storage used by the module is contained in a single structure.
This structure contains global configuration settings, per circuit storage,
circuit group configuration data, and per-call storage all relating to operation
of the ISUP protocol. It also contains internal event queues, timer control
structures and internal buffers for message processing.
3.3 Circuit Group Data Structure
Each circuit group has a data structure within the global ram structure that
contains the user supplied configuration parameters for the circuit group (e.g.
Signaling Point Codes, Circuit Identification and Configuration Options). The
information in the circuit group data structure applies to all circuits in the
circuit group.
3.4 Per Circuit Data Structure
Each circuit has a data structure within the global ram structure that is used
to store the current state of state machines associated with the circuit and
any current call details.
17
Section 3 Internal Data Structures
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Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
4 Interface to System Services
4.1 System Functions
In addition to the primitive interfaces and the management interface to the
ISUP module (which are described in later sections) the module requires a
few basic system services to be supplied by the underlying operating system.
In most cases, this is achieved by the use of the appropriate Development
package.
The following functions are used for inter-task communication:
GCT_send Send a message to another task.
GCT_receive Receive the next message from the module’s input queue, blocking the task if
GCT_grab As GCT_receive, but no blocking if no message is ready.
The following functions are required for message allocations for inter-task
communication:
getm Allocate a message from the system.
relm Release a message back to the system.
no message is ready.
4.2 Timer Operation
In order to provide internal implementation of the ISUP protocol timers the
module needs to receive a periodic timer tick message. This is generated
either by the on-board timer module or the tick and tim binaries supplied as
part of the development package.
The following action request message is issued by the ISUP module:
KEEP_TIME Issued by ISUP to initialize timer services.
The ISUP module expects the following notification on a periodic basis from
the timer module:
TM_EXP Issued by the timer module to notify of periodic timer tick.
The format of these messages is described in Appendix F: Timer Services on
page 199
.
19
Section 4 Interface to System Services
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Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
5 Interface to MTP
The ISUP module interfaces with the Message Transfer Part (MTP) using the
following primitives, all of which are defined in ITU-T Recommendation
Q.704.
MTP-TRANSFER-REQ Transmit message to MTP
MTP-TRANSFER-IND Receive message from MTP
MTP-PAUSE Remote point code unavailable indication from MTP
MTP-RESUME Remote point code available indication from MTP
MTP-STATUS Signaling point congested or Remote user unavailable indication
from MTP
The message format used to convey these primitives is defined in the MTP3
Programmer's Manual.
The ISUP module is usually used in conjunction with the MTP module.
However, the use of primitives in accordance with Q.704 ensures that it can
also be integrated with other MTP implementations if required.
To provide further flexibility the ISUP module supports the use of both
T_FRAMEs and R_FRAMEs or the use of MSGs for MTP-TRANSFERs between
the ISUP and MTP.
T_FRAMES and R_FRAMES are most useful when the ISUP module is running
on the same processor as MTP, whilst MSGs are generally used when the
ISUP module is running on a different processor than the one used for the
MTP, or in conjunction with an MTP other than the Dialogic
A module configuration option (ISPF_TFRM) allows the user to select between
sending T_FRAMEs or sending MSGs. Receipt of both R_FRAMEs and MSGs is
supported in either mode.
®
SS7 Protocols.
21
Section 5 Interface to MTP
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Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
6 Interface to Application
6.1 Introduction
All primitives at the application interface (i.e. between the ISUP module and
the user) are passed by sending messages between the modules. Each
message is of type MSG as defined in the Software Environment
Programmer’s Manual.
The basic structure of each message (irrespective of the message type) is the
same. The message contains a message header, the length of the user data
and the user data. The message must be contained in a single buffer that
should be allocated by the sending module (using the getm function) and
either released (using the relm function) or passed to another module by the
receiving module. The getm and relm functions are described in
Interface to System Services on page 19.
The first sub-section of this chapter describes the format of the message
header associated with each type of message and the next section describes
the format of the user data contained within the message.
6.2 Application Message - Header Format
Two primitive message types are sent between the application and the ISUP
module:
Section : 4
Transmit Request Message from application to ISUP
Receive Indication Message from ISUP to application.
The message structure and parameters for each primitive are defined in the
following paragraphs:
6.2.1 Transmit Request
This primitive is used by the application to send a message to the ISUP
module.
Primitive Request to ISUP
Field Name Meaning
type ISP_MSG_TX_REQ (0xc700)
id call_ref
src Application module ID
dst ISUP module ID
rsp_req 0x00
hclass 0x00
status 0x00
err_info 0x00
len Number of bytes of user data
parameters User data (Len bytes in length)
23
Section 6 Interface to Application
call_ref is used to identify the circuit or call to which the message refers.
Currently, when 32768 circuits or less are configured, the most significant bit
of the
call_ref is ignored by the ISUP module, and the remaining bits map
directly to the Circuit Identifier
cid so the valid range for call_ref is from 0 to
one less than the number of circuits supported. If more than 32768 circuits
are configured, then the call_ref is identical to the cid.
Note: Earlier revisions of the ISUP module required the most significant bit of the
call_ref to be set in all messages relating to outgoing calls.
6.2.2 Receive Indication
This primitive is used by the ISUP module to send a message to the
application module.
Primitive Indication From ISUP
Field Name Meaning
type ISP_MSG_RX_IND (0x8701)
id call_ref
src ISUP module ID
dst Application module ID
rsp_req 0x00
hclass 0x00
status 0x00
err_info 0x00
len Number of bytes of user data
parameters User data (Len bytes in length)
24
call_ref is used to identify the circuit or call to which the message refers.
Currently, when 32768 circuits or less are configured and the ISPF_16CID
flag is set to 0, the most significant bit of the
call_ref is set to 1 by the ISUP
module for all messages relating to outgoing calls and the remaining bits map
directly to the Circuit Identifier
cid. If 32768 circuits or less are configured
and the ISPF_16CID flag is set to 1, or if more than 32768 circuits are
configured, then the call_ref is identical to the cid.
Note: Earlier revisions of the ISUP module required the most significant bit of the
call_ref to be set in all messages relating to outgoing calls. To allow for
interworking with earlier application software which make use of this bit the ISUP
module continues to set the bit in all messages relating to outgoing calls for
configurations with 32768 circuits or less, when the ISPF_16CID flag has been set
to 0. It is recommended that existing applications be modified to ignore the
setting of the most significant bit.
Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
6.3 Application Message - User Data Format
The format of user data in transmit request and receive indication messages
between the Application and the ISUP module is based on the ISUP message
format specified in Q.763.
The first byte of the data is the ISUP message type. The message type
values are specified in Table 4/Q.763 and the last byte of the data is zero to
indicate that there are no further parameters contained within the message.
Any parameters associated with the message are placed between the
message type byte and the last byte of the data. The parameter area is
therefore formatted as follows:
ISUP
Message Type
The parameters may be placed in any order. The first byte of a parameter is
the parameter name (based on Table 5/Q.763 but specified in Section 9 of
this programmer’s manual), the second byte is the length of parameter data
to follow (excluding the parameter name and the length byte itself), this is
followed by the parameter data which is formatted (based on Q.763) as
defined in section 9. Each parameter is therefore formatted as follows:
ISUP
Message Type
Parameter
Name
1 byte 1 byte ‘Length’ bytes (1 to 255)
Parameter Parameter Parameter Zero
Parameter Parameter Parameter
Parameter
Length
Parameter
Data
Zero
Note: Unlike the message format specified in Q.763, there are no 'fixed' or 'variable'
parameters where the parameter name or type are implied by their position in the
message. Instead all parameters contain parameter name, parameter length and
parameter data.
Within each message, there are Mandatory parameters, which must always
be present and Optional parameters, which may or may not be present.
Many of the optional values have default values, which are added by the ISUP
module if not provided by the user as described in the parameter
specification.
All supported application messages are listed in
Section 6.5 on page 26 and
Section 6.6 on page 54. All applicable parameters for each message are
listed in the following sub-sections (refer also to Appendix A: ISUP National
Variants
on page 171) and a list of all supported parameters are provided in
Section : 6.7 Parameter Definitions on page 80.
25
Section 6 Interface to Application
6.4 Parameter Extension Mechanism
The CCPN_parameter type value 128 (0x80) is used as an extension
parameter indicator. The parameter extension mechanism is used for all
parameter types whose decimal value is greater than 255 at the common
control interface. If a parameter value of 128 (0x80) is contained within a
message for sending to or received from the user, the actual parameter type
value (minus 256) is contained in the third byte which is subsequently
followed by the length of the parameter and its data as shown below:
Name Length Data
0x80 Parameter
Length + 2
1 byte 1 byte 1 byte 1 byte ‘Length’ bytes (1 to 253)
Parameter
Name - 256
Parameter
Length
6.5 Application Messages to ISUP
The following table lists all application messages (message type
ISP_MSG_TX_REQ) sent to ISUP module by the user application:
Parameter Data
26
type
Alerting request ACM
CPG
Application transport
request
Charge request
(Generic)
Circuit seized request SZE 199 0xc7 Used to initiate a continuity test call
Confusion request CFN 47 0x2f Requests that a confusion message is
Continuity request COT 5 0x05 Indicates whether the continuity test
Collection charging
request
End-to-end message
request
Facility request FAR
Forward transfer
request
Information request SAM 2 0x02 Subsequent address digits for overlap
APM 65 0x41 To issue an application transport
CRG 49 0x31 Carries charging information.
MPM 201 0xc9 Used to carry charging information.
PAM 40 0x28 Requests that an end-to-end message
FAC
FAA 32 0x20 Used to accept or reject a facility . Facility response
FRJ 33 0x21 Previously requested with a facility
FOT 8 0x08 Send forward transfer to the network.
Value Primitive Message
Dec Hex
6
0x06
44
0x2c
31
0x1f
51
0x33
Indicates incoming called party being
alerted.
message.
and indicates that a circuit has been
seized for an outgoing call (but no
address information has yet been
sent).
sent.
succeeded.
is sent.
Request activation of a particular
facility or action at another exchange.
request.
signaling.
Use
Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
type
Value Primitive Message
Dec Hex
Use
INF 4 0x04 Sends additional call information.
Identification request IDR 54 0x36 Used to request an action regarding
the MCID supplementary service.
Identification
IRS 55 0x37 Used to respond to the IDR mess age.
response
Loop back
acknowledgement
request
Loop prevention
LPA 36 0x24 Indicates to the network that a
continuity check loop has been applied
to the circuits.
LOP 64 0x40 Use with ECT supplementary service.
request
Network resource
management request
NRM 50 0x32 Request modifications to network
resources associated with a call.
Overload request OLM 48 0x30 Used to initiate temporary trunk
blocking.
Pre-release
information request
PRI 66 0x42 Used by the application to request end-
to-end information prior to the release
of a call.
Proceeding request ACM 6 0x06 Indicates incoming called party number
is complete.
Progress request CPG 44 0x2c Carries progress information.
Release request REL 12 0x0c Initiates call clearing.
Release response RLC 16 0x10 Confirms that application has
completed call clearing. (Used when
call clearing has been originated by the
ISUP module).
Request information
INR 3 0x03 Requests additional call information.
request
Resume request RES 14 0x0e Resumes suspended call.
Segmentation
request
SGM 56 0x38 Requests that a message segment is
sent.
Suspend request SUS 13 0x0d Suspends call.
Setup request IAM 1 0x01 Initiates outgoing call.
Setup response ANM
CON
Subsequent Directory
SDM 67 0x43 Subsequent directory number digits for
Number
Unrecognised
UMT 254 0xfe Allows an unsupported message type
message request
User information
USR 45 0x2d Requests that user-to-user data is sent.
9
0x09
7
0x07
Answers incoming call.
overlap signaling
to be sent by the application.
request
27
Section 6 Interface to Application
6.5.1 Alerting Request
This primitive is used by the application to indicate that the called
subscriber's phone is ringing. The primitive takes the form of an Address
Complete message when it is the first backward message issued by the
destination exchange or a Call Progress message after the first backward
message has been issued.
First Backward Message Issued
Message type
ACM (Address Complete Message)
Mandatory parameters
None
Optional parameters
• Backward call indicators
Defaults to 0x1416 if not supplied i.e. Subscriber Free Ordinary
Subscriber, Charge Terminating access ISDN, ISDN used all the way
• Access transport
• Cause indicators
• Call reference
• Optional backward call indicators
• Remote operations
• Service activation
• Transmission medium used
• User to user indicators
May be used to accept user to user information service 1, 2 or 3
(previously requested in a set-up indication).
• User to user information
Discarded if user to user service 1 has not been accepted.
28
The following optional parameters are supported in ITU-T mode only:
• Access delivery information
• Application transport
• Call diversion information
• Conference treatment indicators
• Connected number
• Echo control information
• Generic notification indicator
This parameter may be repeated (see
Parameters
on page 197).
Appendix E: ISUP Repeat
Dialogic® SS7 Protocols ISUP Programmer's Manual Issue 15
• Network specific facility
• Parameter compatibility information
• Redirection number
• Redirection number restriction indicator
• UID action indicators
The following parameters are supported in ANSI mode only:
• Business group
• Generic digits
• Information indicators
• Network transport
• Notification indicator
• Redirection information
Issued following ACM
Message type
CPG (Call Progress Message)
Mandatory parameters
None
Optional parameters
• Access transport
• Backward call indicators
• Cause indicators
• Call reference
• Event information
Defaults to 0x01 if not supplied. i.e. ALERTING
• Optional backward call indicators
• Redirection number
• Remote operations
• Service activation
• Transmission medium used
• User to user indicators
May be used to accept user to user information service 1, 2 or 3
• User to user information
Discarded if user to user service 1 has not been accepted
The following optional parameters are supported in ITU-T mode only:
29
Section 6 Interface to Application
• Access delivery information
• Application transport
• Backward GVNS
• Call diversion information
• Call history information
• Call transfer number
• Conference treatment indicators
• Connected number
• Echo control information
• Generic notification indicator
This parameter may be repeated (see
Appendix E: ISUP Repeat
Parameters on page 197).
• Generic number
• Network specific facility
• Parameter compatibility information
• Redirection number restriction indicator
• UID action indicators
The following optional parameters are supported in ANSI mode only:
• Business group
• Generic number (address)
• Generic digits
• Information indicators
• Network transport
• Notification indicator
This parameter may be repeated (see
Parameters
on page 197).
6.5.2 Application Transport Request
Note: This message is only applicable to ITU operation.
This primitive can be issued in all call states up until release. It is used by
the application to send an application transport message which is passed on
in same direction without changing state.
Message type
APM (Application Transport Message)
Mandatory parameters
None
Appendix E: ISUP Repeat
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