ISDN User Part for national ISDN connections /ISUP-N2

Telecommunications Recommendation 

extension "B-2-1" 

SPECIFICATION FOR 

COMMON CHANNEL SIGNALLING SYSTEM No. 7 

ISDN User Part 

for national ISDN connections 

/ISUP-N2/ 

Version_1 

03/2005 

Makedonski telekom AD – Skopje 

Orce Nikolov bb, 1000 Skopje

ISDN USER PART VERSION 2 FOR THE NATIONAL INTERFACE (ISUP-N2) 

Normative references 

Normative references: 

-ETS 300 356: Signalling System No. 7 ISDN User Part Version 2 for the international interface. 

- ETS 300 356-1 (1995): Basic services [ITU-T Rec. Q. 730 (1993), modified]. 

- ETS 300 356-2 (1995): ISDN supplementary services [ITU-T Rec. Q. 730 (1993), modified]. 

- ETS 300 356-3 (1995): Calling Line Identification Presentation (CLIP) supplementary service [ITU-T 

Rec. Q. 731, clause 3 (1993), modified]. 

- ETS 300 356-4 (1995): Calling Line Identification Restriction (CLIR) supplementary service [ITU-T 


- ETS 300 356-5 (1995): Connected Line Identification Presentation (COLP) supplementary service 

[ITU-T Rec. Q. 731, clause 5 (1993), modified]. 

- ETS 300 356-6 (1995): Connected Line Identification Restriction (COLR) supplementary service [ITU-T 


- ETS 300 356-7 (1995): Terminal Portability (TP) supplementary service [ITU-T Rec. Q. 733, clause 4 

(1993), modified]. 

- ETS 300 356-8 (1995): User-to-User Signalling (UUS) supplementary service [ITU-T Rec. Q. 737, 

clause 1 (1993), modified]. 

- ETS 300 356-9 (1995): Closed User Group (CUG) supplementary service [ITU-T Rec. Q. 735, clause 1 


- ETS 300 356-10 (1995): Subaddressing (SUB) supplementary service [ITU-T Rec. Q. 731, clause 8 


- ETS 300 356-11 (1995): Malicious Call Identification (MCID) supplementary service. 

- ETS 300 356-12 (1995): Conference Call, add-on (CONF) supplementary service [ITU-T Rec. Q. 734, 

clause 1 (1993), modified]. 

- ETS 300 356-14 (1995): Explicit Call Transfer (ECT) supplementary service. 

- ETS 300 356-15 (1995): Diversion supplementary services [ITU-T Rec. Q. 732, clauses 2 to 5 (1993), 

modified]. 

- ETS 300 356-16 (1995): Call Hold (HOLD) supplementary service [ITU-T Rec. Q. 733, clause 2 


- ETS 300 356-17 (1995): Call Waiting (CW) supplementary service [ITU-T Rec. Q. 733, clause 1 


- ETS 300 356-18 (1995): Completion of Calls to Busy Subscriber (CCBS) supplementary service. 

- ETS 300 356-19 (1995): Three Party (3PTY) supplementary service [ITU-T Rec. Q. 734, clause 2 


- EN 300 485v1.3.1.”Integrated Services Digital Network (ISDN).; Definition and usage of cause and 

location in Digital Subscriber Signalling System No1 (DSS1) and Signalling System No7(SS7)ISDN 

User Part (ISUP) [ITU –T Recommendation Q850 (05/98)with addendum (not yet published) 

- ETS 300 403-1 (1995): Digital Subscriber Signalling System No. 1 (DSS 1); Part 1: Protocol 

specification [ITU-T Rec. Q. 931 (1993), modified]. 

- ITU-T Rec. Q.850 (03/93): Usage of Cause and Location in the Digital Subscriber Signalling No. 1 and 

the Signalling System No. 7 ISDN User Part 

“B-2-1” 2 / 35



T a b l e o f c o n t e n t s 

This specification describes the requirements for the National ISDN User Part Version 2 (ISUP-N2) of 

Signalling System No. 7, applicable to the interface of the national transit and local exchanges. The 

objective of the specification is to provide a clear description of the ISDN User Part for the implementers 

and the staff involved in tests, operation and maintenance. The specification is written in English in 

order to align the description as close as possible to the terminology used in ETSI standards and ITU-T 

Recommendations. 

The text of this specification is based on the ETSI Standard ETS 300 356-XX. Where any 

discrepancy exists between the requirements of this specification and any unreferenced part of the 

documents (e.g. SDLs) then these requirements shall be deemed to modify those sections of the 

documents. 

In order to be as close as possible to the relevant ETSI standards, in this document only the 

exceptions and clarifications to the Base document are described. 

As ETS 300 356-XX Standards give the exceptions to ITU-T Recommendations Q. 761 to 764 

and Q. 73X series, this document specifies only the added exceptions and clarifications. If otherwise not 

clearly stated in a Clarification in this specification, the text of the ITU-T Recommendation shall be used 

as modified by the referred ETSI standard. Those parts of the specifications which are marked as 

"national option", "for national use", "reserved", "for further study" are in general not used unless stated 

otherwise. 

Starting with the next Chapter, the current numbering within the Chapters follows the numbering 

scheme of the referenced standards. 

All timer values shall be accurate to within + or - 5% of nominal values. 

“B-2-1” 3 / 35



1 Basic services 

Exceptions and Clarifications to 

ETS 300 356-1 (1995): Signalling System No. 7 ISDN User Part Version 2 for the international interface; 

Part 1: Basic services 

Foreword 

The text is accepted. 

Scope 




Definitions 


Abbreviations 


Global modifications to ITU-T Recommendations Q. 761 to 764 


Modifications to ITU-T Recommendation Q. 761 

Shall apply with the following additional modifications: 

Capabilities supported by the ISDN User Part 

Clarification: Replace table 1/Q.761 by: 

F u n c t i o n / s e r v i c e 

Basic call 

Speech/3.1 kHz audio + 

64 kbit/s unrestricted + 

Multi rate connection types (Note) - 

Signalling procedures for connection type allowing fallback capability - 

Compatibility procedure + 

Confusion procedure + 

Simple segmentation + 

Transit network selection + 

User part availability control + 

Propagation delay determination procedure 

Dynamic echo control procedure 

Tones and announcements + 

MTP pause and resume + 

Access delivery information + 

Transportation of User teleservice information + 

national 

use 

- Note3 

- Note2 

Generic signalling procedures for supplementary services 

End-to-end signalling – Pass along method - 

End-to-end signalling – SCCP Connection Oriented - 

End-to-end signalling – SCCP Connectionless - 

Generic number transfer + 

Generic digit transfer - 

Generic notification procedure + 

Simple service activation procedure - 

Remote operations procedure - 

Network specific facility procedure - 

Supplementary services 

Direct Dialling In (DDI) + 

Multiple Subscriber Number (MSN) + 

Calling Line Identification Presentation / Restriction (CLIP/CLIR) + 

Connected Line Identification Presentation / Restriction (COLP/COLR) + 

Malicious Call Identification (MCID) (without the HOLD option) + 

Sub-addressing (SUB) + 

Terminal portability (TP) + 

Call forwarding (CFU, CFB, CFNR) + 

“B-2-1” 4 / 35



Call deflection (CD) + 

Call waiting (CW) + 

Call hold (HOLD) + 

Conference calling (CONF) + 

Three party service (3PTY) - 

Closed User Group (CUG) + 

Multilevel Precedence and Pre-emption (MLPP) - 

User-to-User Signalling (UUS), Service 1 (implicit) + 

User-to-User Signalling (UUS), Service 1 (explicit) - 

User-to-User Signalling (UUS), Service 2 + 

User-to-User Signalling (UUS), Service 3 - 

Explicit Call Transfer (ECT) - 

Call Completion to Busy Subscriber (CCBS) + 

Free phone (FPH) - 

Key: 

+ Represents HTC support 

- Represents HTC non-support 

Note: Multi rate connection types are 2*64, 384, 1536 and 1920 kbit/s 

Note2 : Static echo control as per Q.767 is supported. 

Note3 : Propagation delay determination procedure is partially supported 

Signalling methods 

Two signalling methods are used in this Recommendation: 

- link-by-link method, 

- end-to-end. 

The link-by-link method is primarily used for messages that need to be examined at each exchange (see 

section 5). The end-to-end methods are used for messages of end point significance (see 

Recommendation Q.730. 1992). 

The link-by-link method may be used for messages of end point significance. 

Only link-by-link method is used. 

5 End-to-end signalling 

Shall not apply. 

6.2 Version Compatibility 

Additional ITU-T national messages set recognized: 

Charge information 

Identification request 

Identification response 

Information 

Information request 

Loop back acknowledgement 

Segmentation 

Unequipped circuit identification code 

User part available 

User part test 

Additional specific national messages set recognized 

Delayed release 

Charging acknowledgement 

Charge band 

Charging information 

Charging pulse 

Charge unit 

Tariff change 

False answer 

A recognized message may be received containing a message compatibility information parameter. 

“B-2-1” 5 / 35



In that case, the message compatibility information parameter is ignored and the (recognized) message 

is processed as described in call control software. 

Sent by, such an additional recognized message however contains the message compatibility 

information parameter which value is set in accordance with the rules pertaining to the functions this 

message relates to (in other words, the message compatibility information parameter is recreated). 

When an unrecognized message is received, containing a message compatibility information parameter 

and that following these compatibility instructions the unrecognized message has to be passed on, then 

it is retransmitted containing a message compatibility information parameter which content is the same 

as the received one. 

Parameter set recognized on the national network. 

This set comprises : 

- the ITU-T recommended minimum parameter set recognized at the international interface 

(parameters numbered from 1 to 29), 

- an additional set of ITU-T parameters, 

- an additional set of national parameters referring to specific national procedures (e.g. charging). 

Additional ITU-T parameters set recognized by: 

Access delivery information 

Call diversion information 

Call history information 

Freephone indicators 

Generic notification 

Generic number 

Information indicators 

Information request indicators 

Location number 

MCID request indicator 

MCID response indicator 

Message compatibility information 

Parameter compatibility information 

Propagation delay counter 

Redirection number restriction 

User teleservice information 

Additional specific national parameters set recognized by an E10 implementation 

Message number 

Charge unit number 

Charge band number 

New charging information 

Next charging information 

Current charging information 

A recognized parameter may be received with corresponding parameter compatibility information 

instruction indicators. 

In that case, the parameter compatibility information instruction indicators are ignored and the 

(recognized) parameter is processed as described in call control software. 

When such an additional recognized parameter is sent by, corresponding parameter compatibility 

information instruction indicators may be inserted in a parameter compatibility information parameter, 

the value of these indicators being set in accordance with the rules pertaining to the functions this 

parameter relates to (in other words, the parameter compatibility information instruction indicators are 

recreated). 

When an unrecognized parameter is received accompanied by parameter compatibility information 

instructions, and that following these compatibility instructions the unrecognized parameter has to be 

passed on, then it is retransmitted accompagnied with parameter compatibility information instructions 

which are the same as the received ones. 

“B-2-1” 6 / 35





1 Signalling messages 

Clarifications: 

- The following definition shall be added: 

1.50 trunk offer message (TKO): A message sent in forward direction indicating an operator's request 

for trunk offering or other operator activity associated with it. 

- For the messages to be used please refer to 'Modifications to ITU-T Recommendation Q. 763'. 

1. GENERAL FUNCTION OF MESSAGES AND SIGNALS 

GENERAL 

This Recommendation describes the elements of signalling information used by the ISDN User Part 

protocol and their function. The encoding of these elements, the format of the messages in which they 

are conveyed and their application in the ISDN User Part signalling procedures are described in 

Recommendations Q.763 and Q.764. Table 1/Q.762 gives the mandatory or optional parameters in the 

ISDN user part messages and Table 2/Q.762 lists the abbreviations of these messages. 

The Table 1/Q.762 is not included in the ITU-T Recommendation Q.762. 

1. Signalling messages 

1. Charge information message (CRG) (national use) 

Information sent in either direction for accounting and/or call charging purposes. 

A message sent in the backward direction indicating either implicit charging information during call setup 

phase or explicit charging units during call conversation phase. 

1. Circuit group query message (CQM) (national use) 

Circuit group query message is not supported. 

A message sent on a routine or demand basis to request the far-end exchange to give the state of all 

circuits in particular range. 

1. Circuit group query response message (CQR) (national use) 

Circuit group query response message is not supported. 

A message sent in response to a circuit group query message to indicate the state of all circuits in a 

particular range. 

1. Delayed release message (DRS) (national use) (not used in 1992 years Recommendation) 

Delayed release message is supported. 

A message sent in the forward direction indicating that the calling party has disconnected but that the 

network is holding the connection. 

1. Facility accepted message (FAA) 

A message sent in response to a facility request message indicating that the requested facility has been 

invoked. 

FAA message is never initiated. 

1. Facility message (FAC) 

Facility message is not supported. 

A message sent in either direction at any phase of the call to request an action at another exchange. 

The message is also used to carry the results, error or rejection of a previously requested action. 

1. Facility request message (FAR) 

A message sent from an exchange to another exchange to request activation of a facility. 

FAR message is never initiated . 

1. Forward transfer message (FOT) (international use) 

Forward transfer message is not supported. 

1. Identification request message (IDR) 

A message sent in either direction to request an action regarding the malicious call identification 

supplementary service. 

1. Identification response message (IRS) 

A message sent in response to the identification request message. 

When initiated by, this message is sent in the forward direction. 

1. Information message (INF) (national use) 

A message sent to convey information in association with a call, which have been requested in an 

information request message. 

When initiated by, this message is sent in the forward direction. 

“B-2-1” 7 / 35



1. Information request message (INR) (national use) 

A message sent by an exchange to request information in association with a call. 

When initiated by, this message is sent in the backward direction. 

1. Loop back acknowledgement message (LPA) (national use) 

A message sent in the backward direction in response to a continuity check request message indicating 

that a loop (or transceiver in case of a 2-wire circuit) has been connected. 

LPA message is never initiated. 

1. Loop prevention message (LOP) 

A message sent in either direction when the loop prevention procedure is performed. 

LOP message is not supported. 

1. Network resource management message (NRM) 

Network resource management message is not supported. 

1. Overload message (OLM) (national use) 

Overload message is not supported. 

1. Pass-along message (PAM) (national use) 

Pass-along message is not supported. 

1. Unequipped circuit identification code message (UCIC) (national use) A message sent 

from an exchange to another when it receives an unequipped circuit identification code. 

UCIC message is never initiated. 

1. Additional national messages 

1. Charging acknowledgement message (CHA) 

The charging acknowledgement message is sent forwards to acknowledge the correct reception of the 

tariff change message or of the charge unit message. 

1. Charge band message (CHB) 

Prior to the establishment of a call, the charge band message ensures the backward transmission of 

implicit charging information from a charging controlling exchange to the originating subscriber 

exchange or to an upstream ISDN exchange. 

1. Charging information message (CHG) 

Prior to the establishment of a call, the charging information message enables the backward 

transmission of explicit charging data from a charging controlling exchange to the originating subscriber 

exchange or to an upstream ISDN exchange. 

1. Charging pulse message (CHP) 

Message sent backwards to the preceeding exchange, each time charging units are applied downwards 

to the communication. When charging is not performed in the local originating exchange, that message 

can be sent on purpose from the hierarchical upper charging point, either systematically or depending 

on specific calling party characteristics (e.g. coinbox, subscriber line with home meter device....). 

1. Charge unit message (CHU) 

The charge unit message, sent backwards from a charging controlling exchange to the originating 

subscriber exchange or to an upstream ISDN exchange provides the number of charging units to be 

applied on its reception. 

1. Tariff change message (TAC) 

The tariff change message is sent backwards from a charging controlling exchange to the originating 

subscriber exchange or to an upstream ISDN exchange to indicate the subsequent tariff changes 

occurring during a call. 

1. False answer message (FSA) 

Message sent backwards in semi automatic traffic during the offering procedure to indicate to the 

national operator that the analogue called subscriber line is in the on-hooking position and then can be 

rung. 

1. Operator message (OPR) 

OPR messages are sent forwards in semi automatic traffic from a national operator to an analogue 

subscriber line during an offering procedure. 

The OPR message can take 3 different meanings according to its position in the call sequence : 

Start of offer (the operator enters as a third party in an existing conversation). 

“B-2-1” 8 / 35



End of offer (the operator withdraws from the 3-party conversation). 

Ringing signal (the operator requests the called party to be rung after having accepted the operator offer 

when on-hooking). This message can also be sent after the conversation phase between the 2 parties 

when the operator wants to re-ring the called subscriber in on-hooking position. 

The sequence "start of offer" "end of offer" can be repeated several successive times. 

2 Signalling information 


- The following definition shall be added: 

2.156 charge band number: Information sent in backward direction to indicate the zone number to be 

used for charging the call. 

2.157 number of charging units: Information sent in backward direction to indicate the number of 

charging units (meter pulses) to be sent. 

- For the signalling information to be used please refer to 'Modifications to ITU-T 

Recommendation Q. 763'. 

Table 2/Q.762 

Clarification: The following message shall be added: TKO (Trunk offer). 

Signalling information 

1. Address presentation restricted indicator 

Information sent in either direction to indicate that the address information is not to be presented to a 

public network user, but can be passed to another public network. It may be also used to indicate that 

the address can not be ascertained. 

In fact, the "Address not ascertained" coding is not part of the ITU-T "Address presentation restricted 

indicators" codings. 

It is the "Address not available" coding that is provided. 

1. Address signal 

An element of information in a network number. The address signal may indicate digit values 0 to 9, 

code 11 or code 12. One address signal value (ST) is reserved to indicate the end of the called party 

number. 

Code 13 and code 14 are added in relation with other national applications. 

1. Call identity (national use) 

Call identity information is not supported. 

************************ 

Information sent in the call reference parameter indicating the identity of a call in a signalling point. 

1. Call reference (national use) 

Call reference parameter is not supported. 

************************ 

Circuit independent information identifying a particular call. 

1. Call transfer number 

Call transfer number parameter is not supported. 

************************ 

The call transfer number parameter is used to exchange the remote party number of the users involved 

in the transfered call. 

1. Call transfer reference 

Call transfer reference parameter is not supported. 

************************ 

The call transfer reference parameter is sent in the Loop prevention message in either direction and 

contains an integer (0,....,255) expressed in pure binary allocated unambiguously to the particular ECT 

service invocation. 

1. Calling party address response indicator (national use) 

Information sent in response to a request for the calling party address, indicating whether the requested 

address is included, not included or not available or incomplete. 

The "incomplete" coding is not part of the ITU-T "Calling party address response indicator" codings. 

“B-2-1” 9 / 35



********************* 

1. Calling party number incomplete indicator 

Information sent in the forward direction indicating that the complete calling party number is not 

included. 

The calling party number incomplete indicator indicates if the calling party number (address signals) 

which is included in the parameter is complete or incomplete. 

When no calling party is included, the address is declared as not available (refer to the address 

presentation restricted indicator). 

********************* 

1. Calling party's category 

Information sent in the forward direction indicating the category of the calling party and, in case of semiautomatic 

calls, the service language to be spoken by the incoming, delay and assistance operators. 

The codings relating to the service languages are unused (reserved for international use). 

************************ 

1. Charge information request indicator (national use) 

Charge information request indicator is not supported. 

************************ 

Information sent in either direction requesting charge information to be returned. 

1. Charge information response indicator (national use) 

Charge information response indicator is not supported. 

************************ 

Information sent in response to a request for charge information indicating whether or not the requested 

information is included. 

1. Circuit state indicator (national use) 

Circuit state indicator is not supported (as the circuit group query procedure is not supported). 

************************ 

Information indicating the state of a circuit according to the sending exchange. 

1. Component type (national use) 

Component type is not supported (as Remote Operations Service Element procedures are not 

supported). 

************************ 

1. Connection request 

Connection request parameter is not supported (as SCCP method of end-to-end signalling is not 

supported). 

************************ 

Information sent in the forward direction on behalf of the signalling connection control part requesting 

the establishment of an end-to end connection. 

1. Credit (national use) 

Credit information is not supported (as SCCP method of end-to-end signalling is not supported). 

************************ 

Information sent in a connection request, indicating the window size requested by the signalling 

connection control part for an end-to-end connection. 

1. Encoding scheme (National use) 

Encoding scheme information is not supported (as the generic digits parameter is not supported). 

************************ 

Information sent to indicate the coding type for the digit information, e.g. BCD-coded. 

1. Error code (national use) 

Error code element is not supported (as Remote Operations Service Element procedures are not 

supported). 

************************ 

The Error Code element contains the reason why an operation cannot be completed successfully. It is 

present only in a Return Error component. As with operations, errors may be local or global. These 

errors and associated parameters are defined in relevant supplementary service specifications. 

1. Event indicator 

Information sent in the backward direction indicating the type of event which caused a call progress 

“B-2-1” 10 / 35



message to be sent to the originating local exchange. 

As the CPG message can be sent in any direction and the Event information parameter is mandatory in 

the CPG message, the Event indicator may also be transmitted forwards to a destination exchange. 

********************* 

1. Event presentation restricted indicator (national use) 

Information sent in the backward direction indicating that the event should not be presented to the 

calling party. 

As the CPG message can be sent in any direction and the Event information parameter is mandatory in 

the CPG message, the Event presentation restricted indicator may also be transmitted in the forward 

direction indicating that the event should not be presented to the connected line. 

********************* 

1. Facility indicator 

Information sent in facility related messages identifying the facility or facilities with which the message is 

concerned. 

1. Freephone indicators 

Freephone indicator is not supported. 

************************ 

Information sent in forward direction indicating whether the call is a freephone call or not. 

1. Generic digits (national use) 

Generic digits parameter is not supported. 

Note(s) : In the generic digits parameter all the "Type of digits" codings are either specified as 

reserved or spare. The use of this parameter is thus for further applications. 

************************ 

Digit information, which is not suitable to be sent within numbering parameter, sent in either direction to 

convey information between exchanges due to supplementary service. 

1. Feature code (national use) 

Feature code information is not supported. 

Note(s) : In the service activation parameter all the features codes are specified as reserved. The 

use of this information is thus for further applications. 

************************ 

Information sent in either direction to invoke, accept, or reject a specific action for a supplementary 

service. 

1. Incoming half echo control device request indicator 

Incoming half echo control device request indicator is not supported (as the dynamic echo control 

procedure is not supported). 

************************ 

Information sent to request the activation or deactivation of an incoming half echo control device. 

1. Incoming half echo control device response indicator 

Incoming half echo control device response indicator is not supported (as the dynamic echo control 


************************ 

Information sent to inform whether an incoming half echo control device has been included or not. 

1. Invoke ID (national use) 

Invoke ID is not supported (as Remote Operations Service Element procedures are not supported). 

************************ 

An Invoke ID is used as a reference number to identify uniquely an operation invocation. It is present in 

the Invoke component and in any reply to the Invoke (Return Result, Return Error or Reject), enabling 

the reply to be correlated with the invoke. 

1. Length of network identification (national use) 

Length of network identification information is not supported. 

************************ 

Information sent in the network specific facility parameter, to indicate the length in octets of the network 

identification. 

1. Length of reference indicator (reserved) 

Length of reference indicator information is not supported. 

************************ 

Information sent in the generic reference parameter, to indicate the length in octets of the reference. 

1. Linked ID (national use) 

Linked ID is not supported (as Remote Operations Service Element procedures are not supported). 

“B-2-1” 11 / 35



************************ 

A Linked ID is included in an Invoke component by a node when it responds to an operation invocation 

with a linked operation invocation. The node receiving the Linked ID uses it for correlation purposes in 

the same way that it uses the Invoke ID in Return Result, Return Error and Reject components. 

1. Local reference 

Local reference is not supported (as SCCP method of end-to-end signalling is not supported). 

************************ 

Information sent in the connection request, indicating the local reference allocated by the signalling 

control part to an end-to-end connection. 

1. Look for busy (LFB) (National use) 

Look for busy information is not supported (as the MLPP supplementary service is not supported). 

************************ 

Information sent in the forward direction to indicate whether the LFB option is allowed or if the path for 

the call is reserved. 

1. Loop prevention indicators 

Loop prevention indicators are not supported. 

************************ 

Information sent in the Loop prevention message in either direction in association with a request (or a 

response to a request) when the loop prevention procedure is performed. 

MLPP service domain information is not supported (as the MLPP supplementary service is not 

supported). 

************************ 

Information sent in the forward direction to identify the specific MLPP service domain subscribed by the 

calling user. 

1. MLPP user indicator (National use) 

MLPP user indicator is not supported (as the MLPP supplementary service is not supported). 

************************ 

Information sent in the backward direction to indicate that the called user is an MLPP user. 

1. Network identification plan (national use) 

Network identification plan information is not supported (as the transit network selection parameter is 

not supported). 

************************ 

Information sent to indicate the identification plan for identifying the network, e.g. X.121 or E.212, (DNIC 

or MNIC). 

1. Network identification (national use) 

Network identification information is not supported (as the transit network selection parameter is not 

supported). 

************************ 

Information sent to identify a network. 

1. Network identity (national use) 

Network identity information is not supported (as the MLPP precedence parameter is not supported). 

************************ 

Information sent to identify the network who administrates the supplementary service. 

1. Network specific facilities (national use) 

Network specific facilities parameter is not supported. 

************************ 

Service related information transparently transferred in either direction between the local exchange and 

the identified network which contracts the service. The information is significant to both user and the 

identified network. 

Information sent in association with a generic number, qualifying the number that is transferred, e.g. a 

network specific number or a number related to a specific supplementary service. 

1. Operation code (national use) 

Operation code element is not supported (as Remote Operations Service Element procedures are not 

supported). 

************************ 

1. Origination ISC point code 

Originating International Switching Centre (ISC) point code parameter is not supported. 

“B-2-1” 12 / 35



************************ 

Information sent in the initial address message of an international call, indicating the point code of the 

originating ISC. 

1. Outgoing half echo control device request indicator 

Outgoing half echo control device request indicator is not supported (as the dynamic echo control 


************************ 

Information sent to request the activation or deactivation of an outgoing half echo control device. 

1. Outgoing half echo control device response indicator 

Outgoing half echo control device response indicator is not supported (as the dynamic echo control 


************************ 

Information sent to inform whether an outgoing half echo control device has been included or not. 

1. Point code 

Point code information is not supported (as SCCP method of end-to-end signalling is not supported). 

************************ 

Information sent in the connection request parameter identifying the signalling point at which connection 

request originated. 

1. Precedence level (National use) 

Precedence level information is not supported (as the MLPP supplementary service is not supported). 

************************ 

Information sent in the forward direction to indicate the priority of the call. 

1. Problem code (national use) 

Problem code element is not supported (as Remote Operations Service Element procedures are not 

supported). 

************************ 

1. Protocol class 

Protocol class information is not supported (as SCCP method of end-to-end signalling is not supported). 

************************ 

Information sent in the connection request parameter indicating the protocol class requested by the 

signalling connection control part for the end-to-end connection. 

1. Protocol profile (national use) 

Protocol profile information is not supported (as Remote Operations Service Element procedures are 


************************ 

Information sent in either direction to indicate the protocol used in the Remote Operations parameter. 

1. Redirection number restriction indicator 

Information sent in the backward direction indicating whether the diverted-to user allows the 

presentation of his number. 

In Recommendation Q.763, the Redirection number restriction information is not specified as an 

indicator. This information is specified as a parameter containing a Presentation restricted indicator. 

********************* 

1. Reference nth octet (reserved) 

Reference nth octet information is not supported. 

************************ 

Information sent in the generic reference parameter, expressing the reference number of the context 

given by the entity which handles and provides the service. 

1. Reference qualifier indicator (reserved) 

Reference qualifier indicator is not supported. 

************************ 

Information sent in the generic reference parameter, identifying the context which handles and provides 

the service. 

1. Remote operations (national use) 

Remote operations parameter is not supported (as Remote Operations Service Element procedures are 


************************ 

The remote operations parameter is used to indicate the invocation of a supplementary service 

identified by an operation value and also carry the result or error indications depending on the outcome 

of the operation. 

“B-2-1” 13 / 35



1. Sequence (national use) 

Sequence Tag is not supported (as Remote Operations Service Element procedures are not supported). 

************************ 

The sequence is an ordered set. 

1. Service activation parameter 

Service activation parameter is not supported. 

************************ 

Information sent in either direction to indicate the invocation, acceptance or rejection of supplementary 

services, when no service associated parameter is to be sent. 

1. Set (national use) 

Set element is not supported (as Remote Operations Service Element procedures are not supported). 

************************ 

The set element is used to contain a set of information elements accompanying a component. It is 

required in the case of more than one information elements being included in a component. The 

information elements themselves are defined in relevant supplementary service specifications. 

1. Signalling point code (national use) 

Signalling point code parameter is not supported. 

************************ 

Information sent in a release message to identify the signalling point in which the call failed. 

1. Temporary trunk blocking after release (national use) 

Temporary trunk blocking after release is not supported (as the temporary trunk blocking (TTB) 


************************ 

Information sent to the exchange at the other end of a circuit (trunk) to indicate low level of congestion 

at the sending exchange and that the circuit (trunk) should not be re-occupied by the receiving 

exchange for a short period of time after release. 

TTB information is not explicit information (e.g. a parameter, an indicator). This information is implicitly 

delivered by the overload message. 

********************* 

1. Transit network selection (national use) 

Transit network selection parameter is not supported. 

************************ 

Information sent in the initial address message indicating the transit network(s) requested to be used in 

the call. 

1. Transmission medium requirement prime 

Transmission medium requirement prime parameter is not supported. 

************************ 

Information sent in the forward direction indicating the fallback connection type in case of fallback. 

1. Transmission medium used 

Transmission medium used parameter is not supported. 

************************ 

Information sent in the backward direction indicating a resulting fallback connection type used for a call 

after fallback has occurred. 

1. Type indicator 

Information sent to indicate the initiator for a circuit group supervision message, e.g. maintenance 

oriented or hardware failure oriented. 

A better description of the Type indicator is given hereafter: 

Information sent by the initiator to indicate the type of blocking/unblocking in a circuit group 

blocking/unblocking supervision message, e.g. maintenance oriented or hardware failure oriented. 

********************* 

1. Type of digits (national use) 

Type of digits information (generic digits parameter) is not supported. 

************************ 

Information sent in association with a generic digit to indicate the type of digit, e.g. authorization code. 

1. Type of network identification (national use) 

Type of network identification information (transit network selection parameter) is not supported. 

Information sent to inform whether the identification of a network is by CCITT standardization 

identification or by national network identification. 

1. User service information prime 

“B-2-1” 14 / 35



User service information prime parameter is not supported. 

Information sent in the forward direction indicating the additional bearer capability requested by the 

calling party. 

1. Additional national parameters 

1. Tariff indicator 

The tariff indicator provides the basic charge coefficient to apply in a periodic-charging procedure. 

1. Tariff factor 

The tariff factor is a number which, when multiplied by the basic charge coefficient indicated by the tariff 

indicator, gives the real charging period (in seconds). 

1. Time indicator 

The time indicator gives the time at which the next change of charging will occur. 

1. Charge unit number 

Information sent to the outgoing subscriber exchange which indicates the number of charge units to be 

recorded on the calling subscriber's meter. 

1. Message number 

This information allows the checking of in-sequence reception of several charge unit messages relating 

to the same call. 

1. Packet charging 

Packet charging, sent backwards, indicates the number of charging units to apply either upon answer or 

connect message reception. 

1. Current charging information 

Sent backwards, the current charging information provides the charging data to be applied upon 

reception of the answer or connect message. 

1. Next charging information 

Sent backwards, the next charging information provides the charging data to be applied at the time 

indicated by the time indicator. 

1. New charging information 

Sent backwards, the new charging information provides the new charging period to be applied at the 

time indicated by the time indicator. 

1. Charge band number 

The charge band number allows the receiving exchange (the exchange which elaborates charging) to 

retrieve in its own tables the corresponding explicit charging data (i.e., packet charging, charging period, 

charging switchover time). 

Table A-2/Q.762 - ISDN user part message acronyms 

Acronym 

Message 

ACM 

Address complete 

ANM 

Answer 

BLA 

Blocking acknowledgement 

BLO 

Blocking 

CCR 

Continuity check request 

CFN 

Confusion 

CGB 

Circuit group blocking 

CGBA 

Circuit group blocking acknowledgement 

CGU 

Circuit group unblocking 

CGUA 

Circuit group unblocking acknowledgement 

CON 

Connect 

COT 

Continuity 

CPG 

Call progress 

CRG 


CQM 

Circuit group query 

CQR 

Circuit group query response 

DRS 

Delayed release 

FAA 

Facility accepted 

FAC 

Facility 

“B-2-1” 15 / 35



FAR 

FOT 

FRJ 

GRA 

GRS 

IAM 

IDR 

IRS 

INF 

INR 

LOP 

LPA 

NRM 

OLM 

Facility request 

Forward transfer 

Facility reject 

Circuit group reset acknowledgement 

Circuit group reset 

Initial address 

Identification request 




Loop prevention 

Loop back acknowledgement 

Network resource management 

Overload 

Table A-2/Q.762 - ISDN user part message acronyms (continued) 

Acronym 

Message 

PAM 

Pass along 

REL 

Release 

RES 

Resume 

RLC 

Release complete 

RSC 

Reset circuit 

SAM 

Subsequent address 

SGM 

Segmentation 

SUS 

Suspend 

UBL 

Unblocking 

UBA 

Unblocking acknowledgement 

UCIC 

Unequipped circuit identification code 

UPA 

User part available 

UPT 

User part test 

USR 

User-to-user information 

Acronyms of the additional national messages 

Acronym 

Message 

CHA 

Charging acknowledgement message 

CHB 

Charge band message 

CHG 

Charging information message 

CHP 

Charging pulse message 

CHU 

Charge unit message 

TAC 

Tariff change message 

FSA 

False answer message 

OPR 

Operator message 

************************ 



In the national application, the four spare bits are unused : they are coded "0" (zero) on transmission, 

and are ignored in reception. 

Multiple 64 kbit/s connection type calls are not supported. 

2.1 Message type codes 


- The following message type code shall be added: Trunk offer (Code: 1111 1111). 

- The following messages shall be used: 

Address complete 

Answer 

Blocking 

Blocking acknowledgement 

“B-2-1” 16 / 35



Call progress 

Circuit group blocking 

Circuit group blocking acknowledgement 

Circuit group reset 

Circuit group reset acknowledgement 

Circuit group unblocking 

Circuit group unblocking acknowledgement 


Confusion 

Connect 

Continuity 

Continuity check request 

Facility 

Facility accepted 

Facility reject 

Facility request 

Forward transfer 

Identification request 1 




Initial address 

Loop prevention 

Release 

Release complete 

Reset circuit 

Resume 

Segmentation 

Subsequent address 

Suspend 

Trunk offer 

Unblocking 

Unblocking acknowledgement 

User Part available 

User Part test 


- Any other message will never be sent, and if received it shall be treated according to 

2.9.5.2/Q.764. 

3 ISDN User Part parameters 

3.1 Parameter names 


- The following parameter type codes shall be added: 

Charge band number (Code: 1111 1111) 

Number of charging units (Code: 1111 1110). 

3.2 to 3.61 Description of the parameters 


- The following parameter value shall be added to the Calling party's category parameter: 

1111 1110 Intelligent Network call 

- The following parameters shall be added: 

3.AA Charge band number 

The format of the Charge band number parameter field is shown below: 

8 7 6 5 4 3 2 1 


The following codes are used in the charge band number parameter field: 

00000000 No charge 

00000001 

to > Binary representation of the charge band number to be applied 

1 This message is never sent according to this specification. 

“B-2-1” 17 / 35



11111111 

3.AB Number of charging units 

The format of the Meter pulse number parameter field is shown below: 

8 7 6 5 4 3 2 1 

Number of charging units 

The following codes are used in the charge band number parameter field: 

00000000 spare 

00000001 

to > Binary representation of the number of charging units to be sent 

11111111 

- The following parameters and parameter values shall be used: 

Access delivery information Access delivery indicator no set-up 

message generated 

set-up message generated 

Access transport Access transport as defined in Q.931 

Automatic congestion level 

Automatic congestion level congestion 

level 1 exceeded 

congestion level 2 exceeded 

Backward call indicators Charge indicator no indication 

no charge 

charge 

Called party’s status indicator 

no indication 

subscriber free 

Called party’s category ind. 

no indication 

ordinary subscriber 

payphone 

End-to-end method indicator 

no end-to-end method available 

Interworking indicator 

no interworking encountered 

interworking encountered 

End-to-end information ind. 

no end-to-end information available 

ISDN User Part indicator 

ISDN User Part not used all the way 

ISDN User Part used all the way 

Holding indicator 

holding not requested 

holding requested 

ISDN access indicator 

terminating access non-ISDN 

terminating access ISDN 

Echo control device indicator 

IC half echo control dev. not included 

IC half echo control device included 

SCCP method indicator 

no indication 

Call diversion information Notification subscr. option unknown 

presentation not allowed 

pres. allowed with redirection number 

pres. allowed without redirection nr 

Redirection reason 

unknown 

user busy 

no reply 

unconditional 

deflection during alerting 

deflection immediate response 

mobile subscriber not reachable 

Call history information 

The call history information parameter 

is pure binary representation the propagation delay value of a call in ms. 

Call transfer number as of 'Calling part number' not supported 

Call transfer reference Call transfer reference any value not 

supported 

Called party number 

Odd/even indicator even number of 

address signals 

odd number of address signals 

Nature of address 

subscriber number 

national (significant) number 

international number 

network routing number concatenated 

“B-2-1” 18 / 35



with Called 

Internal network number ind. 

Numbering plan indicator 

Address signal digit 0 

to 

digit 9 

code 11 

code 12 

ST 

DN(8) 

routing to INN allowed 

routing to INN not allowed 

ISDN/Telephony numbering plan 

Filler 

as required(In case of an odd number of 

address signals ,the filter code 0000 is inserted after the last address signal) 

Calling party number 

Odd/even indicator as of 'Called party 

number' 

Nature of address indicator 

as of 'Called party number' 

Calling party number inc. ind 

complete 

incomplete 

When sending the calling party number parameter, if the calling party number incomplete indicator is set 

to ‘incomplete’, then the nature of address indicator is set to ‘national (significant) number. 

When receiving the calling party number parameter, if the calling party number incomplete indicator is 

set to ‘incomplete’, then no check is performed on the nature of address indicator (i.e. all the values of 

the nature of address indicator are accepted). 



Address presentation restr. ind presentation allowed 

presentation restricted 

address not available 

When the address presentation restricted indicator indicates address not available, the screening 

indicator (item f)) is coded "network provided". 

Screening indicator 

user provided, verified and passed 

network provided 

User provided, verified and passed" and 

"network provided" codes can be initiated by E10 system. 

Address signal 


Filler 

as required(In case of an odd number of 

address signals ,the filter code 0000 is inserted after the last address signal) 

Calling party’s category Calling party’s category operator, 

language French 

operator, language English 

operator, language German 

operator, language Russian 

operator, language Spanish 

national operator (0000 1001) 

ordinary subscriber 

subscriber with priority 

data call (voice band data) 

test call 

payphone 

Intelligent Network call (1111 1110) 

The following Calling party's categories are introduced: 

- "national operator with offer facility" (coding according to above ITU-T note). 

This coding is set when the call is initiated by a national operator. 

- "calling subscriber with home metering or advice of charge" (coding in the range reserved for 

national use). 

This coding is set when the analogue user owns a home (charging) metering device or when 

the ISDN user has subscribed to the advice of charge during call conversation phase (AOC-D) 

supplementary service and/or to the advice of charge at the end of the call(AOC-E) supplementary 

service. 

- "calling subscriber with remote immediate charge indication" (coding in the range reserved for 

national use). 

This coding is set when the user (ISDN or analogue) requires by using a special prefix before 

his numbering, the immediate charge indication to the charging intermediate exchange. 

- "interception service" (coding in the range reserved for national use). 

“B-2-1” 19 / 35



This coding is set when the call is initiated by an interception operator. 

Cause indicators All fields As defined in EN 300 485v1.3. 

1 standard (including Addendum 1, ITU Q.850) 

CCBS parameter 

CCBS call indicator no indication 

CCBS call 

Charge band number Charge band number any pattern 

Circuit group supervision 

type ind. Type indicator maintenance oriented 

hardware failure oriented 

Circuit state indicator 

not supported 

Closed user group interlock 

code Any field any pattern 

Connected number 


number' 





Address presentation restr. ind as of 'Calling party number' 


as of 'Calling party number' 



Filler 

as required 

Connection request 

not supported 

Continuity indicators 

Continuity indicator continuity check failed 

continuity check successful 

Echo control information 

not supported 

End of optional parameters 

End of optional parameters End of 

optional parameters 

The last optional parameter field of a 

message is followed by the end of optional parameters indicator, which occupies a one octet field 

containing all zeros. 

Event information Event indicator alerting 

progress 

in-band info/pattern is now available 

call forwarded on busy 

call forwarded on no reply 

call forwarded unconditional 

Event presentation restr. ind. 

no indication 

When the event information parameter is 

initiated, the event presentation restricted indicator is always set to 0”no indication” 

In reception, bit H is handled with the “no 

indication” meaning even if bit H is received set to the value “presentation restricted” 

Facility indicator Facility indicators user-to-user service 

Forward call indicators National/international call ind. call to 

be treated as a national call 

call to be treated as an internat. call 

End-to-end method indicator 

as of 'Backward call indicators' 

Interworking indicator 


End-to-end information ind. 


ISDN User Part indicator 


ISDN User Part preference ind. ISDN user part preferred all the way 

ISDN user part not required 

ISDN user part required all the way 

ISDN access indicator 

SCCP method indicator 

indication 

Generic Digits 

Generic notification 

in the next octet 

Notification indicator 

originating access non-ISDN 

originating access ISDN 

as of 'Backward call indicators' no 

not supported 

Extension indicator information continues 

last octet 

user suspended 

user resumed 

conference established 

conference disconnected 

other party added 

“B-2-1” 20 / 35



isolated 

reattached 

other party isolated 

other party reattached 

other party split 

other party disconnected 

conference floating 

call is a waiting call 

call transfer, alerting 

call transfer, active 

remote hold 

remote retrieval 

call is diverting 

Generic number Number qualifier indicator additional 

called number 

additional connected number 

additional calling party number 

additional original called number 

additional redirecting number 

additional redirection number 

called freephone number 


number' 



Number incomplete 

as of 'Calling part number' 


Address presentation restr. ind as of 'Calling part number' 



user provided, not verified 

user provided, verified and passed 

user provided, verified and failed 

network provided 


as required 

not supported 

Calling party address resp. ind. calling 


Filler 

Generic Reference 


party address not available 

calling part address included 

Hold provided indicator 

hold not provided 

hold provided 

Calling party's category resp. ind. calling party's category not incl. 

calling party’s category included 

Charge information resp. ind. 

charge information not included 

Solicited information indicator solicited 

Information request indicators Calling party address req. ind. calling 

party address requested 

calling party address not required 


holding not requested 

holding requested 

Calling party's category req. ind. calling party's category not reqd 

calling party’s category requested 

Charge information request ind. charge information not requested 

Malicious call iden. req. ind. 

malicious call identification requested 

malicious call identification not 

requested 

Location number 


number' 









as of 'Calling party number' 



Filler 

as required 

Loop prevention indicators 

not supported 

Type request 

“B-2-1” 21 / 35



response 

Response indicator 

insufficient information 

no loop exists 

simultaneous transfer 

MCID request indicators MCID request indicator MCID 

requested 


MCID not requested 

Holding not requested 

Holding requested 

MCID response indicators MCID response indicator MCID not 

included 

MCID included 

Hold provided indicator 

Message compatibility info 

interpretation 

Hold not provided 

Holding provided 

Transit at intermediate node ind. transit 

end node interpretation 

Release call indicator 

do not release call 

release call 

Send notification indicator 

do not send notification 

send notification 

Discard message indicator 

do not discard message (pass on) 

discard message 

Pass on not possible indicator 

release call 

discard information 

Extension indicator 

last octet 

MLPP Precedence 

not supported 

Nature of connection indicators Satellite indicator no satellite circuit in the connection 

one satellite circuit in the connection 

two satellite circuit in the connection 

Continuity check indicator 

continuity check not required 

continuity check reqd on this circuit 

cont. check perfd on previous circuit 

Echo control device indicator 

OG half echo control dev. not incl. 

OG half echo control device included 

Network specific facility 

not supported 

Number of charging units Number of charging units any pattern 

Optional backward call ind. In-band information indicator no 

indication 

in-band information/pattern available 

Call diversion may occur ind. 

no indication 

call forwarding may occur 

Simple segmentation indicator no additional info will be sent 

additional info will be sent in a SGM 

MLPP user indicator 

no indication 

Optional forward call ind. 

Closed user group call ind. non-CUG call 

CUG call, OG access allowed 

CUG call, OG access not allowed 

Simple segmentation indicator as of 'Optional backward call ind.' 

Connected line id. req ind 

not requested 

requested 

Original called number 


number' 










Filler 

as required 

Origination ISC Point Code 

not supported 

Parameter compatibility info 

N th upgraded parameter name as 

required 

Transit at intermediate node ind. transit interpretation 

Release call indicator 

end node interpretation 

do not release call 

“B-2-1” 22 / 35



release call 

Send notification indicator 

do not send notification 

send notification 

Discard message indicator 

do not discard message (pass on) 


Discard parameter indicator 

do not discard parameter (pass on) 

discard parameter 

Pass on not possible indicator 

release call 


discard parameter 

Extension indicator 

next octet exist 

last octet 

Propagation delay counter 

The propagation delay counter 

parameter expresses in pure binary representation the propagation delay value of a call in ms to be 

accumulated during call set up. 

Range and status Range ant pattern 

a) Range 

A number in pure binary representation ranging from 1 to 255. The number represented by the 

range code +1 indicates the range of circuits affected by the message. 

b) Status 

The status subfield contains from 2 to 256 status bits numbered from 0 to 255. Status bit 0 is 

located in bit position 1 of the first status subfield octet. Other status bits follow in numerical order. The 

number of relevant status bits in a given status subfield is equal to range +1. 

Each status bit is associated with a circuit identification code such that status bit n is associated 

with circuit identification code m+n, where m is the circuit identification code contained in the message. 

The status bits are coded as follows : 

- in circuit group blocking messages 

0 no indication 

1 blocking 

- in circuit group blocking acknowledgement messages 


1 blocking acknowledgement 

- in circuit group unblocking messages 


1 unblocking 

- in circuit group unblocking acknowledgement messages 


1 unblocking acknowledgement 

- in circuit group reset acknowledgement messages 

0 not blocked for maintenance reasons 

1 blocked for maintenance reasons 

The number of circuits affected by a group supervision message is limited to 32 or less. For the 

group reset messages this requires that the range value be 31 or less. For the group blocking and 

unblocking messages the range value may be up to 255, but the number of status bits set to 1 must be 

32 or less. 

For the group blocking, unblocking and reset messages, range code 0 is reserved. 

Status 

any pattern 

Redirecting number 


number' 










Filler 

as required 

Redirection information Redirecting indicator no redirection 

call rerouted 

call rerouted all redirection information 


call diversion 

call diversion, all info restricted 

“B-2-1” 23 / 35




call diversion, redir. number restrd 

Original redirection reason 

Redirection counter 001 to 101 

Redirecting reason 

call rerouted, redirection number 

unknown/not available 

user busy 

no reply 

unconditional 

unknown/not available 

user busy 

no reply 

unconditional 

deflection during alerting 

deflection immediate response 

mobile subscriber not reachable 

Redirection number 


number' 










Filler 

as required 

Redirection number restriction 

Presentation restricted ind. presentation 

allowed 


Remote operations 

not supported 

Service activation Feature code call transfer not 

supported 

Signalling point code Signalling point code any pattern 

not supported 

Subsequent number 


number' 



Filler 

as required 

Suspend/resume indicators Suspend/resume indicator ISDN 

subscriber initiated 

network initiated 

Transit network selection 

number 

odd/even indicator as of Called Party 

Type of network identification 

national network identification 

Network Identification plan 0(zero) 

Network identification Network 

identification 

Transmission medium req Transmission medium req speech 

64 kbit/s unrestricted 

3.1 kHz audio 

64 kbit/s preferred 

2×64 kbit/s unrestricted 



Transmission medium req prime Transm. medium req prime speech not supported 


3.1 kHz audio 

Transmission medium used All fields as of transmission medium 

req. not supported 

User service information All fields according to Q.931 

User service information prime All fields according to Q.931 not 

supported 

User teleservice information All fields according to Q.931 

User-to-user indicators, request type 

Service 1 / 2 / 3 

no information 

request, not essential 

request, essential 

“B-2-1” 24 / 35



response type 

Service 1 / 2 / 3 no information 

not provided 

provided 

Network discard indicator 

UUI discarded by the network 


no indication 

any pattern 

- Any other parameters or parameter values not listed above will never be sent, and if 

received it shall be treated according to 2.9.5.2/Q.764. 

1. National parameters 

1. Current charging information 

Format of the current charging information parameter : 

8 7 6 5 4 3 2 1 

Packet charging 

Tariff indicator 

Tariff factor 

FIGURE 3.N1 - Current charging information parameter field 

1) Packet charging : 

00000000 

to 

packet charging coding 

00001111 

00010000 

to 

spare 

11111111 

2) Tariff indicator : 

00000000 charging coefficient 0 : flat rate charge 

00000001 charging coefficient 1 : 0.05 second 





00000110 charging coefficient 6 : 2.0 seconds 

00000111 charging coefficient 7 : 4.0 seconds 

00001000 

to 

spare 

00001111 

00010000 

to 

reserved for future 

11111111 

3) Tariff factor : 

00000000 spare 

00000001 

to 

tariff factor coding 

11111111 

1. Next charging information 

Format of the next charging information parameter: 

8 7 6 5 4 3 2 1 

Time indicator 

spare 

Packet charging 


Tariff factor 

FIGURE 3.N2 - Next charging information parameter field 

“B-2-1” 25 / 35



1) Time indicator : 

00 000 00 immediate tariff change 

00 000 01 00 hr. 15 

00 000 10 00 hr. 30 

00 000 11 00 hr. 45 

00 001 00 01 hr. 00 

00 001 01 01 hr. 15 

00 001 10 01 hr. 30 

... 

10 111 11 23 hr. 45 

11 000 00 24 hr. 00 

11 000 01 

to 

spare 

11 111 11 

2) Packet charging : 

refer to current charging information parameter 





1. New charging information 

Format of the new charging information parameter: 

8 7 6 5 4 3 2 1 

Time indicator 

spare 


Tariff factor 

FIGURE 3.N3 - New charging information parameter field 

1) Time indicator : 

refer to next charging information parameter 





1. Charge band number 

Format of the charge band number: 

8 7 6 5 4 3 2 1 


FIGURE 3.N4 - Charge band number parameter field 

00000000 

to 

charge band number coding 

11111111 

1. Charge unit number 

Format of the charge unit number parameter : 

8 7 6 5 4 3 2 1 

Charge unit number 

FIGURE 3.N5 - Charge unit number parameter field 

00000000 spare 

00000001 

to 

charge unit number coding 

11111111 

1. Message number 

Format of the message number parameter: 

8 7 6 5 4 3 2 1 

Message number 

FIGURE 3.N6 - Message number parameter field 

00000000 spare 

“B-2-1” 26 / 35



00000001 

to 

11111111 

message number coding 

4 ISDN User Part messages and codes 

Table 24/Q.763: Circuit group query response not supported 

TABLE 25/Q.763 - Message Type : Circuit group reset acknowledgement 

Parameter 

Reference Type Length Implem. 

(subclause) 

(octets) 

Message type 2.1 F 1 F 

Range and status 3.43 V 3-34 V 

When sent by E10 exchange, the length of the range and status field is 3-6 octets since 32 circuits at 

most are concerned. 

TABLE 26/Q.763 - Message Type : Confusion 

Parameter 


(subclause) 

(octets) 


Cause indicators 3.12 V 4-20 V 

End of optional parameters 3.20 O 1 O 

The correct length for the Cause indicators parameter is 3-. 

TABLE 27/Q.763 - Message Type : Connect 

Parameter 


(subclause) 

(octets) 


Backward call indicators 3.5 F 2 F 

Optional backward call indicators 3.37 O 3 O 

Connected number 3.16 O 4-12 O 

Call reference @ 3.8 O 7 - 

User-to-user indicators 3.60 O 3 O 

User-to-user information 3.61 O 3-131 O 

Access transport 3.3 O 3- O 

Network specific facility @ 3.36 O 4- - 

Generic notification ind. (Note) 3.25 O 3 O 

Remote operations @ 3.48 O 3- - 

Transmission medium used 3.56 O 3 - 

Echo control information 3.19 O 3 - 

Access delivery information 3.2 O 3 O 

Call history information 3.7 O 3 O 

Parameter compatibility information 3.41 O 4- O 

Redirection number 3.46 O 5-12 O 

Service activation 3.49 O 3- - 

Generic number (Note) 3.26 O 5-13 O 

Redirection number restr. 3.47 O 3 O 


Note(s) : This parameter may be repeated. 

The correct length of the Call history information parameter is 4. 

TABLE 29/Q.763 - Message Type : Facility reject 

Parameter 


(subclause) 

(octets) 


“B-2-1” 27 / 35



Facility indicator 3.22 F 1 F 

Cause indicators 3.12 V 4 V 

User-to-user indicators 3.60 O 3 O 


The Cause indicators parameter should have a length (octets) of 3-. 

Clarification to Table 30/Q.763: The format of the Information message is: 

TABLE 30 Message type: Information 

Parameter name Reference Type Length 

Message type 


Calling party number 


2.1 

3.28 

3.10 

3.20 

F 

F 

O 

O 

1 

2 

4-12 

1 

Clarification to table 31/Q.763: The format of the Information request message is: 

TABLE 31 Message type: Information Request 


Message type 

Information request indicators 

2.1 

3.29 

TABLE 34/Q.763 - Message Type : Release complete 

Parameter 


(subclause) 

(octets) 


Cause indicators 3.12 O 5-6 O 


The Cause indicators parameter should have a length (octets) of 4- 

F 

F 

1 

2 

TABLE 37/Q.763 - Message Type : Forward transfer not supported 

TABLE 39/Q.763 - Message Type : Blocking - Blocking acknowledgement - Continuity check 

request - Loop back acknowledgement @ - Overload @ - Reset circuit - Unblocking - Unblocking 

acknowledgement - Unequipped circuit identification code @ 

Parameter 


(subclause) 

(octets) 


Overload message is not supported. 

TABLE 41/Q.763 - Message Type : Circuit group reset a) - Circuit group query a) not supported 

TABLE 43/Q.763 - Message Type : Pass-along not supported 

TABLE 45/Q.763 - Message Type : Facility 

Facility message is not supported 

TABLE 46/Q.763 - Message Type : Network resource management not supported 

TABLE 47/Q.763 - Message Type : Identification request 

Parameter 


(subclause) 

(octets) 


MCID request indicators 3.31 O 3- O 

Message compatibility information 3.33 O 3- O 


End of optional parameter 3.20 O 1 O 

The correct length (octets) of the MCID request indicators parameter is 3. 

TABLE 48/Q.763 - Message Type : Identification response 

“B-2-1” 28 / 35



Parameter 


(subclause) 

(octets) 


MCID response indicator 3.32 O 3- O 

Message compatibility information 3.33 O 3- O 


Calling party number 3.10 O 4-12 O 

Access transport 3.3 O 3- O 

Generic number (Note) 3.26 O 5-13 O 

End of optional parameter 3.20 O 1 O 

Note(s) : This parameter may be repeated. 

The correct length (octets) of the MCID response indicators parameter is 3. 

1. NATIONAL MESSAGES 

TABLE N1 - Message Type : Charge information message (CRG) 

Parameter Type Length (octets) 

Message type F 1 

Charge band number O 3 

Charge unit number O 3 

Message compatibility information O 3 

End of optional parameters O 1 

TABLE N2 - Message Type : Charging information message (CHG) 



Current charging information O 5 

Next charging information O 6 


TABLE N3 - Message Type : Tariff change message (TAC) 



New charging information F 3 


TABLE N4 - Message Type : Charge band message (CHB) 



Charge band number F 1 


TABLE N5 - Message Type : Charge unit message (CHU) 



Charge unit number F 1 

Message number F 1 


TABLE N6 - Message Type : Charging acknowledgement message (CHA) 




TABLE N7 - Message Type : Charging pulse message (CHP) 


“B-2-1” 29 / 35




Charge unit number O 3 


TABLE N8 - Message Type : Messages related to operators - Operator message (OPR) - False 

answer message (FSA) 



Message compatibility information O 3 


TABLE N9. - Message Type : Delayed release 

Parameter Type Length Implem. 

(octets) 

Message type F 1 F 

Call reference @ O 7 - 

End of optional parameters O 1 O 

Clarification (general): The following messages shall be added: 

TABLE AA Message type: Trunk offer 


Message type 2.1 F 1 

TABLE AB Message type: Charge information 


Message type 



Message compatibility 

information 

Parameter compatibility 

information 


2.1 

3.AA 

3.AB 

3.33 

3.41 

3.20 

F 

O 

O 

O 

O 

O 

1 

3 

3 

3 

4 

1 

Annex A: Interpretation of spare codes 

Clarification to 3.13 (Circuit supervision message type indicator) of Table A2/Q.763: Type 

indicator: in case of receiving unrecognized parameter value of this field, the message is discarded and 

a Confusion message is sent with cause value 110. Reserved bits H-C: the information is ignored. 

Clarification to 3.35 (Nature of connection indicators), Satellite indicator of Table A3/Q.763: In 

case of receiving unrecognized parameter value of this field, Confusion message is not sent. 



2 Basic call control and signalling procedures 

2.1 Successful call setup 

2.1.1 Forward address signalling - En-bloc operation 

2.1.1.1 Actions required at the originating exchange 

Clarification to item a): The selection of the outgoing route will also depend on the calling party's 

category. 

Clarification to item b): On national calls, the address information may be the local number or 

the national number as well. 

Clarification to item c): The originating or interworking exchange always sends the calling party 

number. If it is not available, the appropriate indication is sent. 

“B-2-1” 30 / 35



The call reference and SCCP connection request parameters are not used. 

Clarification to item d): Through connection of the transmission path will be completed in the 

forward direction after receiving the Answer or Connect Message. 

2.1.1.2 Actions required at an intermediate national exchange 

Clarification to item a): The selection of the outgoing route will also depend on the calling party's 

category. The user service information and the user teleservice information is not used for routing 

purposes. The transmission medium requirement parameter is not modified. 

2.1.1.3 Actions required at an outgoing international exchange 

Clarification to item a): As of 2.1.1.2.a). 

Clarification to item b): If the received calling party number is not in international number format, 

then it is converted to international number (i.e. country/trunk code is added) and the nature of address 

is set to "international number". 

2.1.1.4 Actions required at an intermediate international exchange 


2.1.1.5 Actions required at an incoming international exchange 


Clarification to item b): As of 2.1.1.3.b). The incoming international exchange deletes the 

originating ISC point code parameter from the Initial Address Message. 

Clarification to item c): As of 2.1.1.1.d). 

2.1.1.6 Actions required at the destination exchange 

Clarification to item a): The selection of the called party will also depend on the calling party's 

category. 

2.1.2 Forward address signalling - Overlap operation 

Clarifications: As of 2.1.1. 

Clarification to 2.1.2.1 item d): Through connection of the transmission path in the backward 

direction at the originating exchange will be completed immediately after sending the Initial Address 

Message. 

2.1.3 Calling party number 

Clarification: The calling party number is always included in the initial address message. If the 

number is not available, the appropriate indication ("address not available") is sent. The calling party 

number is requested only if it was not included in the initial address message (e.g. in case of 

interworking with exchanges using an earlier version of ISUP). 

2.1.4 Address complete message, connect message and call progress message 

Clarification to item 2.1.4.2 and 2.1.4.4: The Awaiting Answer Timer (T9) is not used in the 

intermediate national and intermediate international exchanges. 

Clarification to item 2.1.4.6.b): In case of test calls, the Awaiting Answer Timer (T9) is not 

started. 

2.1.6 Information messages 

Clarification: This function is used for Malicious call identification purpose. If the MCID service is 

activated (or appropriate indication is received in an interworking exchange) and no calling party number 

parameter is included in the Initial address message, the calling party number is requested by sending 

an Information request message (calling party address requested, malicious call identification 

requested) backward. 

2.1.9 Charging 


Basically the originating local exchange is the charge controlling exchange, and it determines 

the charging depending on the called party number. In some circumstances (e.g. IN call, international 

calls) it is necessary to send charging information from the succeeding exchange. This is done via the 

Charge information (CRG) message. In case of IN call, the SSP (Service Switching Point) generates the 

CRG message based on the received information from the SCP. 

If no Charge information message is received, the originally stored charging program applies. If 

a Charge band number parameter is received in the Charge information message during the call setup 

(before the answer), the message is stored in the exchange. If more than one Charge information 

messages are received, the latest one will be valid. On receipt of the ANM message charging based on 

the received charge band number is started in the originating local exchange, or meter pulses are 

“B-2-1” 31 / 35



generated in an interworking exchange. 

If a Charge band number parameter is received in the active phase of a call, charging activities 

related to the charge band number in use are immediately terminated. The charging activities are 

resumed applying the new charge band number. 

If a Number of charging units parameter is received in the active phase of a call, the charging 

units are applied (added) in the originating local exchange, or additional meter pulses are sent in the 

R2-N interworking exchange. 

2.1.10 Transit network selection 

Clarification: Shall apply 

2.1.13 Trunk offering (MT specific requirement) 

The Trunk offer message (TKO) is used to handle the calls originated by a long distance 

operator. A call to a free subscriber is set up as a normal call without any special message. When the 

called party is busy but available to the operator, the operator can offer the long distance call by sending 

a TKO message. 

If the calling party is an operator, the response is an Address Complete message with In-band 

info indication, cause value 17 (subscriber busy) and a busy tone from the called exchange to the 

operator (instead of Release message). If the trunk offer is not possible, a Release message with cause 

value 42 (switching equipment congestion) is sent. When the operator has informed the subscriber that 

a call is waiting, the operator can escape from the call by sending a repeated TKO message. 

When the called party (to whom the operator wishes to offer a call) becomes free with his 

handset off-hook (i.e. the partner goes on-hook), an Answer message is sent, and the conversation 

begins, as shown below: 

+-----------+ +-----------+ 

¦ Operator ¦ ¦Destination¦ 

¦ ¦ ¦ exchange ¦ 

+-----------+ +-----------+ 

¦ ¦ 

¦------------IAM------------->¦ called subscriber 

¦ ¦ busy 

¦¦ operator access 

¦ ¦ 

¦¦ 

¦ trunk offering ¦ 

¦ ¦ 

¦------------TKO------------->¦ operator escapes 

¦ ¦ 

¦¦ called subscriber 

¦ ¦ busy 

¦¦ operator access 

¦ ¦ 

“B-2-1” 32 / 35



¦¦ 

¦ trunk offering ¦ 

¦ ¦ 

¦------------TKO------------->¦ operator escapes 

¦ ¦ 

¦



echo control device is already included, then no additional action is required. 

Backward direction, actions at the destination exchange 

Upon the receipt of an IAM with the indication "outgoing half echo control device included" in the nature 

of connection indicators parameter field, then an incoming half echo control device is enabled; and the 

echo control device indicator of the backward call indicators parameter field in the first backward 

message (i.e. ACM or connect or call progress) is set. If the destination exchange is unable to include 

an incoming half echo control device, the information is conveyed to the preceding exchange by an 

echo control device indicator in the backward call indicators parameter field in the first backward 

message. 

Backward direction, actions at an intermediate exchange 

Upon receipt of the first backward message (i.e. ACM or connect or call progress) in response to an IAM 

with echo control indication, then one of the following actions can occur: 

a) When the backward call indicators parameter field indicates that an incoming half echo control 

device is not already included, then the reserved incoming half echo control device is included, and the 

echo control device indicator in the backward call indicators parameter field is set. 

b) When the backward call indicators parameter field indicates that an incoming half echo control 

device is already included, then the reserved incoming half echo control is released, and no change to 

the backward call indicators parameter field in the backward message is made. 

2.8.3 Circuit group query 

Clarification: This function is not used. 

2.9.1 Dual seizure 

Clarification to item 2.9.1.3 Method 1: The exchange with lower signalling point code will start 

the selection from the lowest CIC and the other starts from the highest. 

2.9.9 Temporary trunk blocking after release 

Clarification: This function is not used. 

TABLE A1/Q.764: Timers used in the ISDN User Part 

Clarification: T 6 = 90 sec (default value) 

T 9 = 90 sec (default value) 

Annex ZA: Coding of the compatibility information for basic calls 

Clarifications: Add the following coding to the list: 

ZA.1.1.2 Charge information 

a) Instruction indicators 

bit A: Transit at intermediate exchange indicator 

0 transit interpretation 

bit B: Release call indicator 

1 release call 

bit C: Send notification indicator 

1 send notification 

bit D: Discard message indicator 

X don't care 

bit E: Pass on not possible indicator 

X don't care 

b) Extension indicator 

1 last octet 

ZA.1.2.3 


a) N th upgraded parameter 

1111 1111 Charge band number 

b) Instruction indicators 






“B-2-1” 34 / 35





X don't care 

bit E: Discard parameter indicator 

X don't care 

bit GF: Pass on not possible indicator 

XX don't care 


1 last octet 

ZA.1.2.4 


a) N th upgraded parameter 

1111 1110 Number of charging units 

b) Instruction indicators 








X don't care 

bit E: Discard parameter indicator 

X don't care 

bit GF: Pass on not possible indicator 

XX don't care 


1 last octet 

“B-2-1” 35 / 35

ISDN User Part for national ISDN connections /ISUP-N2

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