SKMM MTSFB TC T003 :2013  
 
 
  
TECHNICAL CODE  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
SPECIFICATION  FOR PRIVATE AUTOMATIC BRANCH EXCHANGE 
(PABX) SYSTEM FOR CONNECTION TO PUBLIC SWITCHED 
TELEPHONE NETWORK (PSTN)  
 
First Revision  
 
 
 
 
 
 
 
 
 
 
Developed by   Registered by  
  
 
 
Issued date : 31 January 2013  
 
 
© Copy right 201 3SKMM  MTSFB  TC T003 :2013  
 
i 
  
DEVELOPMENT OF TECHNICAL CODE S 
 
 
The Communications and Multimedia Act 1998 (‘the Act’) provides for Technical Standards Forum 
designated under section 184 of the Act or the Malaysian Communications and Multimedia 
Commission (‘the Commission’) to prepare a technical code. The technical code prepared pursuant to 
section 185 of the Act shall consist of, at least, the requirement for network interoperability and the 
promotion of safety of network facilities.  
 
Section 96 of the Act also provides for  the Commission to determine a technical code in accordance 
with section 55 of the Act if the technical code is not developed under an applicable provision of the 
Act and it is unlikely to be developed by the Technical Standards Forum within a reasonable t ime. 
 
In exercise of the power conferred by section 184 of the Act, the Commission has designated the 
Malaysian Technical Standards Forum Bhd (‘MTSFB’) as a Technical Standards Forum which is 
obligated, among others, to prepare the technical code under sec tion 185 of the Act.  
 
A technical code prepared in accordance with section 185 shall not be effective until it is registered by 
the Commission pursuant to section 95 of the Act.  
 
For further information on the technical code, please contact:  
 
Malaysian Com munications and Multimedia Commission (SKMM)  
Off Pesiaran Multimedia  
63000 Cyberjaya  
Selangor Darul Ehsan  
MALAYSIA  
 
Tel: +60 3 8688 8000  
Fax: +60 3 8688 1000  
http://www.skmm.gov.my  
 
OR 
 
Malaysian Technical Standards F orum Bhd (MTSFB ) 
L2-E-11, Lab 3, Digital Media Centre  
Enterprise 4  
Technology Park Malaysia  
Lebuhraya Puchong –Sg Besi  
Bukit Jalil  
57000 Kuala Lumpur  
MALAYSIA  
 
Tel: +60 3 8996 5505/5509  
Fax: +60 3 8996 5507  
http://www .mtsfb.org.my  
 
 
 
 
 
 
 SKMM  MTSFB TC T003 :2013 
ii 
  
 
 
CONTENTS  
 
 
Committee Representation  ................................ ................................ ................................ ....................  iii 
Foreword  ................................ ................................ ................................ ................................ ................  iv 
1. Scope  ................................ ................................ ................................ ................................ ..............  1 
2. Normative references  ................................ ................................ ................................ ......................  1 
3. Abbreviations ................................ ................................ ................................ ................................ ... 1 
4. Requirements  ................................ ................................ ................................ ................................ .. 2 
4.1  General requirements  ................................ ................................ ................................ ............  2 
4.2  Technical requirements  ................................ ................................ ................................ ..........  3 
Acknowledgement  ................................ ................................ ................................ ................................ ... 9 
 
Table  
 
Table 1.  Ringing Signal and Service Tone ................................ ................................ .............................  5 
 
Annex  
 
Annex A : Normative references  ................................ ................................ ................................ ..............  7 
 SKMM  MTSFB  TC T003 :2013  
 
iii 
  
Committee Representation  
 
 
The Fixed Terminal Working Group under the Malaysian Technical Standards Forum Bhd (MTSFB) 
which developed this Technical C ode consists of representatives from the following organisations:  
 
AJV Holding Sdn Bhd  
Epson  Malaysia  
NEC  Corporation of Malaysia Sdn. Bhd.  
Packet One Networks (Malaysia) Sdn. Bhd.  
SIRIM QAS  International Sdn Bhd  
Telekom Malaysia Berhad  
TIME dot com  
Panasonic Malaysia  
Panasonic System Networks  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 SKMM  MTSFB TC T003 :2013 
iv 
  
FOREWORD  
 
 
This technical code for the Specification for Private Automati c Branch Exchange (PABX) System for 
Connection to Public Switched Telephone Network (PSTN)  (‘this Technical Code’) was developed 
pursuant to section 185 of the Act 588 by the Malaysian Technical Standard Forum Berhad (‘MTSFB’) 
via its Fixed Terminal Workin g Group.  
 
This Technical Code was developed for the purpose of certifying communications equipment under 
the Communications and Multimedia (Technical Standards) Regulations 2000.  
 
This Technical Code  cancels and replaces Technical Specification for Private  Automatic Branch 
Exchange (PABX) System for Connection to Public Switched Telephone Network (PSTN) , SKMM 
FTS P PABX  Rev. 1.01:2007 . 
 
This Technical Code  shall continue to be valid and effective until reviewed or  cancelled . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 SKMM  MTSFB  TC T 003:2013  
 
 1  
SPECIFIC ATION  FOR PRIVATE AUTOMATIC BRANCH EXCHANGE (PABX) 
SYSTEM FOR CONNECTION TO PUBLIC SWITCHED TELEPHONE NETWORK 
(PSTN)  
 
 
1. Scope  
 
This document  describes  the requirement of Private Automatic Branch Exchange (PABX) system 
connected to Public Switched Telepho ne Network (PSTN).  
 
 
2. Normative references  
 
The following normative references are indispensable for the application of this document . For dated 
references, only the edition cited applies. For undated references, the latest edition of the normative 
references (including any amendments) applies.  
 
See Annex A.  
 
 
3. Abbreviations  
 
For the purposes of this document, the symbols and abbreviations given in Table 1 apply.  
 
AC Alternating Current  
 
DC Direct Current  
 
EIRP  Effective Isotropic Radiated Power  
 
ETSI European Telecommunications Standards Institute  
 
FCC Federal Communications Commission  
 
IEC International Electrotechnical Commission  
 
SKMM  Malaysian Communications and Multimedia Commission  
 
TE Terminal equipment  
 
 
 
 
 
 
 
 
 
 
 
 
 
 SKMM  MTSFB TC T003 :2013 
 2  
4. Requirements  
 
4.1  General requirements  
 
4.1.1   Power supply requirements  
 
4.1.1.1 - For AC powered TE, the operating voltage shall be rated/ marked at 230V or 240V in line 
with the country's nominal voltage and frequency in accordance to MS IEC 60038. If the product is 
rated with multiple or a range of voltages, voltage range between 230V (+10%, -6%) shall be included. 
Testing shall be conducted based on 230V (+10%, -6%) or 240V and other relevant voltages, if the 
product is marked with multiple or a range of voltages.  
 
4.1.1.2 - Product shall be rated/ marked at 50Hz and testing shall be conducted at 50Hz. If the 
product is marked at 50/60Hz or 50 -60Hz then testing shall be conducted either at 50Hz or 60Hz, 
whichever is more unfavourable.         
 
4.1.1.3 - The design of the  TE shall be such that all essential items of equipment of the TE shall be 
powered from batteries on float charge such that the performance of the system shall not deteriorate 
in any way on failure of the electricity mains supply.  Non essential test equip ment and other auxiliary 
devices may directly work off the electricity mains supply.  
 
4.1.1.4 - The system shall operate on 48 volts  (nominal) with positive earthing , and shall function 
satisfactorily within a voltage range of 42 volts to 54 volts for not less than 80% of the calls and shall 
function satisfactorily within a voltage range of 44 to 52 volts for 100% of the calls.  
 
4.1.1.5 - Where external power supply is used, e.g. AC adaptor or battery, it shall not affect the 
capability of the TE to meet th is specification.  
 
4.1.1.6 - Adaptor shall be pre -approved by the relevant regulatory body before it can be used with the 
TE. 
 
4.1.2   Power supply cord and mains plug requirements  
 
TE shall be fitted with a suitable and appropriate approved power supply co rd and mains plug. Both 
are regulated products and shall be pre -approved by the relevant regulatory body before it can be 
used with the TE.  
 
The power supply cord shall be certified according to : 
 
- MS 140; or  
 
- BS 6500; or  
 
- IEC 60227 -5; or 
 
- IEC 60245 -4. 
 
The main plug shall be certified according to:  
 
- 13 A fused plugs: MS 589: Part 1 or BS 1363: Part 1; or  
 
-  15A plugs complying to MS 1577 or BS 546; or  
 
- 2.5 A, 250 V, flat non -rewirable two -pole plugs: MS 1578 or BS EN 50075.  
 
 SKMM  MTSFB  TC T 003:2013  
 
 3 4.1.3   Polarity  
 
The perfo rmance of the TE shall be independent of the PSTN line polarity i.e. the TE shall conform to 
both polarities of the line feeding (ETSI ES 203 021 -1, clause A.3 ). 
 
4.1.4   Interoperability and connectivity requirements  
 
TE shall comply with the minimum requi rement that is specified by the regulatory body.  
 
4.1.4.1   Interoperability  
 
TE shall be able to exchange information and to use the information that has been exchanged 
between two or more systems or components.  
 
4.1.4.2   Connectivity  
 
TE shall be able to link with other programs and devices to allow interoperability.  
 
4.1.5   Marking requirements  
 
TE shall be marked with the following information:  
 
a) supplier/manufacturer’s name or identification mark;  
 
b) supplier/manufacturer’s model or type reference; a nd  
 
c) other markings as required by the relevant standards.  
 
The markings shall be legible, indelible and readily visible.  
 
4.1.6   Language  
 
All markings, software and related documents shall be in Bahasa Melayu or English language.  
 
4.1.7   Electromagnet ic Compatibility and electrical safety requirements  
 
4.1.7.1   TE shall comply with the limits for conducted disturbance at the mains terminals and 
telecommunication ports, and the limits for radiated disturbance defined in the IEC CISPR 22.  
 
4.1.7.2   TE sh all comply with the MS IEC 60950 -1 safety standard. The requirements in MS IEC 
60950 -1 that are applicable to the TE e.g. class of equipment, type of telecommunication network 
voltage (TNV) circuit and types of components] shall be identified and complied  with. 
 
4.2  Technical requirements  
 
4.2.1  Extension Telephones & Exchange Lines  
 
The PABX supplied shall be able to accept the use of :  
 
i)  Dual tone multi -frequency (DTMF) push -button telephones.  
 
ii)  Rotary dial telephones.  
 
iii) Mixture of i) and ii)  above.  
 
 
 SKMM  MTSFB TC T003 :2013 
 4  
PABX connected to PSTN shall be designed to meet the following requirements:  
 
a)  Where PABX system is connected to PSTN, in addition to complying this technical specification, 
it shall comply with the requirements for connection to PSTN, MTFSB  PSTN : 2011  
 
b)  Where PABX system supported A -CLIP, in addition to complying this technical specification, it 
shall comply with A -CLIP require ment, MTFSB ACLIP : 2011 . 
 
4.2.2.   Tones, Cadences  
 
4.2.2.1   The frequency and cadence for the tones shall comp ly with the specification in Table 1.  
The allowable frequency deviation is ± 5 % of nominal value.  
 
4.2.2.2   The ring back tone shall be returned to the calling party whenever an extension line in the 
system is being rung, irrespective of whether the call is internal or external.  
 
4.2.2.3   PABX with capacity above 100 extensions shall be incorporated with NU tone facilities and 
shall comply with Table 1.  
 
4.2.3   Ringing Current  
 
4.2.3.1   Cadence of ringing current shall comply with the specification in Tabl e 1. 
 
4.2.3.2   Ringing current generator shall have open circuit voltage of not less than 75 V rms and not 
greater than 85 V rms and a design nominal frequency within the range of 16 Hz to 25 Hz. The total 
harmonic distortion shall not exceed 30 %.  
 
4.2.3.3  Terminal voltage on full load shall be at least 60 V rms. SKMM  MTSFB  TC T 003:2013  
 
 5  
Table 1.  Ringing Signal and Service Tone  
 
NO. TYPE OF TONE  CADENCE  
(Second)  FREQUENCY 
(Hz) LEVEL  
(dBm)  
1 Ringing Current  0.4 ON 0.2 OFF  
0.4 ON 2.0 OFF  16-25 
 75 V rms 
 
2 Dial Tone  Continuous  425 -15  to –9 
 
3 Ring 
tone Internal 
call 1.0 ON,  
3.0 to 5.0 OFF  425 -12 
External 
call 0.4 ON, 0.2 OFF  
0.4 ON, 2.0 OFF  425 -15  to –9 
 
4 Ring 
back 
tone Internal 
call 0.4 ON, 0.2 OFF  
0.4 ON, 2.0 OFF  425 - 12.0 
External 
call 0.4 ON, 0.2 OFF  
0.4 ON, 2.0 OFF 425 -15  to –9 
 
5 Busy Tone  
(Engage tone)  0.5 ON, 0.5 OFF  
 425 -15  to –9 
 
6 Congestion tone  Either,  
i)  0.5 ON, 0.5 OFF  
OR 
ii) 0.25 ON, 0.25 OFF  
 425 -15  to –9 
 
7 Intrusion warning 
tone 0.2 ON, 0.2 OFF  
0.2 ON, 5.0 OFF  425 -15  to –9 
 
8 Number 
Unobtainable (NU) 
tone 2.5 ON, 0.5 OFF  425 -15  to –9 
 
 
4.2.4   Numbering Scheme  
 
4.2.4.1   The numbering scheme shall be as follows:  
 
2xxx   )  
3xxx   )                          
4xxx   )   Extension Numbers  
5xxx   )  
6xxx   )  
7xxx   )   Extension Number/Abbreviate d Dialling  
8x    Tie Lines *  
9     Access to Exchange Lines  
0     PABX Operator  
1xx    Services  
 
 
NOTE.  * Tie lines is a leased/dedicated circuit linking two PABXs located in different     
 premises.  
 
4.2.4.3   TE with up to 50 extension lines, two digits n umbering is acceptable.  
 
4.2.4.4   TE with more than 50 extension lines and up to 500 extension lines, three digits numbering 
shall be used.  
 
 SKMM  MTSFB TC T003 :2013 
 6  
4.2.4.5   TE with more than 500 extension lines, four digits and above shall be used, depending on 
the capacity of  the system.  
 
4.2.4.6   Access digit for the public exchange lines shall be ‘9’.   
 
4.2.4.7   Access digit for the operator shall be ‘0’.   
 
4.2.4.8   The first digit of tie -lines access code shall be ‘8’.   
 
4.2.5   Transmission Requirements  
 
4.2.5.1   Extensi on Line Circuit  
 
The equipment shall function satisfactorily with an extension line loop resistance of up to  
1 500 ohms with a leakage resistance of down to 20 000 ohms.    
 
4.2.5.2   Attenuation  
 
Transmission attenuation for the following call at 1,000 Hz , measured at respective termination of the 
system shall be as follows:  
 
a)  Extension to Extension less than 8 dB.  
 
b)  Extension to Exchange line circuit less than 2.5 dB.  
 
4.2.6   Route Restrictions  
 
4.2.6.1   The route restriction equipment shall be of the type that counts the total number of digits 
dialled as well as analyse the number of pulses of the first two or three digits so as to render the route 
restriction facility as fool -proof as possible.  
 
4.2.6.2   Alternatively the digit analysis in the ro ute restriction equipment shall commence analysis of 
the first digit dialled only after the route restriction equipment detects the public exchange dial tone.  
 
The route restriction equipment shall reactivate the digit analysis function whenever the public  
exchange dial tone is detected.  
 
4.2.6.3   First two digit “00” and first three digit “101”, “103” and “108” are barred.  
 
 
 
 
 
 
 
 
 
 
 
 SKMM  MTSFB  TC T 003:2013  
 
 7  
Annex A  
(Normative)  
 
 
Normative references  
 
 
BS 1363: Part 1  13 A plugs, socket -outlets, adaptors and connection units - Part 1: 
Specification for rewirable and non -rewirable 13 A fused plugs  
 
BS 546  
 Specification for AC power plugs and sockets  
 
BS 6500  
 
 
 Electric cables Flexible cords rated up to 300/500 V, for use with 
appliances and equipment intended for domestic, o ffice and similar 
environments  
BS EN 50075  
 Specification for flat non -wirable two -pole plugs 2.5 A 250 V, with 
cord, for the connection of class II -equipment for household and 
similar purposes  
 
ETSI ES 203 021  Access and Terminals (AT); Harmonized basic  attachment 
requirements for Terminals for  connection to analogue interfaces of 
the Telephone Networks;  Update of the technical contents of  TBR 
021, EN 301 437, TBR 015, TBR 017  
 
IEC 60227 -5 
 Polyvinyl chloride insulated cables of rated voltages up to and  
including 450/750 V - Part 5: Flexible cables (cords)  
 
IEC 60245 -4 
 Rubber insulated cables - Rated voltages up to and including 
450/750 V - Part 4: Cords and flexible cables  
 
IEC CISPR 22  Information Technology Equipment - Radio disturbance 
characteris tics - Limits and methods of measurement  
 
ITU-T Recommendation E.16 1 Arrangement of digits, letters and symbols on telephones and other 
devices that can be used for gaining access to a telephone network  
 
MS 140  
 Specification for insulated flexible cords  and cables  
MS 1577  
 
 Specification for 15A plugs and socket -oulets for domestic and 
similar purposes  
MS 1578  
 Specification for flat non -rewirable two -pole plugs, 2.5 A, 250 V, with 
cord, for the connection of class II -Equipment for household and 
simila r purposes  
MS 589: Part 1  
 Specification for 13 A plugs, socket outlets, adaptors and connection 
units Part 1: Specification for rewirable and non -rewirable 13 A fused 
plugs  
 
MS IEC 60038  IEC standard voltages  
 
MS IEC 60950 -1 Information technology equi pment - Safety - Part 1: General 
requirements  
 
 SKMM  MTSFB TC T003 :2013 
 8 SKMM MTFSB TC T001 : 
2012 Specification for terminal equipment connecting to the Public 
Switched Telephone Network (PSTN)  
 
SKMM MTFSB TC T002 : 
2012 Specification for Analogue calling line Identity presentati on (A -CLIP) 
facility for connection to Public Switched Telephone Network (PSTN)  SKMM MTSFB TC T003 :2013  
 
 
 Acknowledgements  
 
 
Members of the Fixed Terminal Working Group : 
 
Abd  Hamid Mustafa (Chairman)  Telekom Malaysia Berhad  
Ahmad Faizan Pardi (Vice Chairman)  SIRIM QAS Internati onal Sdn Bhd  
Nur Rashidah Abas Azmi (Secretary)  Telekom Malaysia Berhad  
Shahadan Man                                         AJV Holding Sdn   Bhd  
Zulkhairi Zainal Abi din                     Epson Malaysia  
Tan Keok Kuang   NEC  Corporation of Malaysia Sdn   Bhd  
Khairul Akmal Zahri                               Packet One Networks Sdn   Bhd  
Syed Ahmad Anas   Packet One Networks Sdn   Bhd  
Pang Chieng Yong  Panasonic Malaysia  
Sam Choong  Panasonic Malaysia  
Mohd Ackmal Abd   Samad                                 Panasonic System Networks  
Hafizah Zainal Abi ddin  SIRIM QAS  International Sdn Bhd  
Nurha fenah Abdul Jalil  SIRIM QAS  International Sdn  Bhd 
Zul Jaafar  SIRIM QAS  International Sdn  Bhd 
Amin Hapis Khairan  Telekom Malaysia Berhad  
Badariah Zainal  Telekom Malaysia Berhad  
Mazram Idzuny  Telekom Malaysia Berhad  
Md Azmi Karnain  Telekom Malaysia Berhad  
Mohamad Ali Abu Bakar                       Telekom Malaysia Berhad  
Mohd Syaukiazah ar Telekom Malaysia Berhad  
Muhd Hadzir Abu Hassan  Telekom Malaysia Berhad  
Nor Maizatul Syima        Telekom Malaysia Berhad  
Nur Faliza Yaakup  Telekom Malaysia Berhad  
Raja Nor Suha  Telekom Malaysia Berhad  
Rosliza Abu Bakar                                          Telekom Malaysia Berhad  
Suriyati Rahim  Telekom Malaysia Berhad  
Wan Nur Hanani  Telekom Malaysia Berhad  
Othman Sidek                                          TIME  dot com