e-mail: doug.burrus@telecom.co.nz

TELECOM ACCESS STANDARDS NEWSLETTER NO. 107
JULY/AUGUST 1998

CONTENTS

POTENTIAL PABX TOLL FRAUD
YEAR 2000 COMPLIANCE
AMENDMENT No. 1 TO PTC 100
a. EXPIRY AND RE-CERTIFICATION OF TELEPERMITS
b. YEAR 2000 COMPLIANCE
c. HARM TO THE NETWORK
d. EXPLANATION OF AMENDMENTS
EXPIRY OF 3-WIRE HARDWARE TELEPERMITS
TNA 150: Telecom Telephone Network numbering Plan
Attachment: AMENDMENT No. 1 TO PTC 100
return to index

POTENTIAL PABX TOLL FRAUD

The attention of PABX installers and maintainers is drawn to the possibility of toll fraud arising when customer's equipment provides any form of interconnection, intended or otherwise, between two network lines.

This matter was dealt with in earlier Newsletters and it was understood that the incidence of toll fraud through unauthorised access to private networks and systems has been fairly low in recent years. However, a case has been reported to us and it is worth publishing another general warning to system maintainers.

The fraud in question arose after a customer with an existing PABX system had a DDI adapter installed. Each incoming trunk connects via one of these devices to a PABX extension port, so that the PABX can use the last digits of the DDI number to route the call to the specified extension. All in all, this is an effective means of providing DDI for those smaller PABX systems that do not support the facility. However, some precautions are required. Some small PABX systems do not provide clear back signals to the calling extension when the called extension releases a call, but simply return the calling extension to dial tone. As a result, an "informed caller" accessing the PABX from the PSTN is able to call in to an extension, wait till the extension releases the call, get PABX dial tone and start dialling - to anywhere! In the case in question, the extension ports were not toll-barred, with the obvious result. This situation was made worse by someone publishing full access details on the Internet.

The message for PABX maintainers is that any extension ports using such arrangements should either be toll-barred or have some form of PIN access to control fraudulent calling. It is recommended that all PABX systems be checked regularly to ensure that the intended toll-barring restrictions are correctly applied and all in place.

PSTN - PABX network - PSTN toll bypass operation has become quite popular since deregulation, as it permits employees and other authorised persons to dial through the private network and thereby avoid toll charges. Again, if maintainers do not make sure that unauthorised access is blocked, their clients could suffer losses.

A variation on the PSTN - PSTN by-pass theme is access from the PABX to the cellular network, so that calls are charged at cellular rates - which are often cheaper and may even include hundreds of "free minutes" each month. Provided that a suitable interface box has been installed, any PABX extension can make "cellular" calls. Where these systems are in use, it would pay to ensure that fraudsters cannot access the PABX, the PSTN, and the international network beyond it, simply by dialling the cellular number of the interface box. Note that this could well be "disclosed" to any called party with "Caller Display" if display restrict has not been applied on calls originating via the interface box.

Return to Contents

YEAR 2000 COMPLIANCE

Further to the article in Newsletter No. 106, Telecom has adopted the following as its formal definition of Year 2000 compliance:-

"Year 2000 compliance means that a product or service so designated shall be able to accurately process date data (including, but not limited to, calculating, comparing, and sequencing) from, into, during and between the 20th and 21st centuries, including leap year calculations, provided that all third party products and services used in combination with the product/service properly exchange date data within it"

If Telecom, its customers and their suppliers are to avoid problems with CPE after 31 December 1999, we need to provide some sort of compliance information for all types of CPE used on the Telecom network. We are now keen to make a start on this process.

Following their receipt of Newsletter No. 106, I am pleased to report that Fisher & Paykel's Panasonic Division responded very promptly with a listing of their products and the level of compliance achieved. As amplification of the Telecom definition above, Fisher & Paykel referred me to the following set of basic rules for determining compliance, as published by the British Standards Institution (BSI):-

"Year 2000 conformity shall mean that neither performance nor functionality is affected by dates prior to, during and after year 2000. In particular:

1. No value for current date shall cause any interruption in operation;

2. Date-based functionality must behave consistently for dates prior to, during, and after year 2000;

3. In all interfaces and data storage, the century in any date must be specified either explicitly or by unambiguous algorithms or inferencing rules;

4. Year 2000 must be recognised as a leap year"

Readers wishing to get further information from BSI are referred to their website:

http://www.bsi.org.uk/disc/year2000/2000.html

A fifth rule - not from BSI - but logical and applicable to a large number of Telepermitted CPE:

5. Products which do not incorporate a date function can be considered to be Year 2000 compliant.

Pending wider publication of the Telepermit Register on the Internet, we will make a start on showing the Y2K compliance of products in the next printed edition (due for publication on 30 September). In the meantime, we look forward to Y2K compliance reports from other suppliers so that we can progressively up-date the Register to provide our customers with a comprehensive guide on product compliance.

Return to Contents

AMENDMENT No. 1 TO PTC 100

The primary document supporting the Telepermit system is Specification PTC 100: 1987 -"Telecom Permit to Connect: General Conditions". This document has been deliberately left unchanged since the original version, as we have been keen to demonstrate the stability of the system.

Nevertheless, there have been numerous developments over the years and a completely new edition would now be desirable to better cover the practices and arrangements which have been established since 1987, such as "limited permit trials". It is proposed that the new edition will incorporate the contents of Amendment No. 1 and be re-structured to more clearly set out the obligations of the Telepermit Holder. A number of issues have arisen to justify an immediate interim amendment prior to the new edition. These are dealt with in the following explanatory information.

A copy of Amendment No. 1 in A5 format is attached to this Newsletter. Replacement A4 format pages will be made available free of charge. Readers holding the A4 format version are invited to request the amended pages from Access Standards.

In line with our usual practice, Amendment No. 1 is initially issued as a "Draft for Public Comment" and may be subject to change in the light of any comments received from any parties affected by the revised clauses. I will advise the final text of this amendment in a future Newsletter. Any comments, questions or suggestions are to be forwarded to Access Standards by 14 September 1998.

Return to Contents

a. Expiry and re-certification of Telepermits

The question of "sunsetting" Telepermits has been raised from time to time within Telecom. This has arisen in connection with the old Post Office 100-type dial telephones, bellsets, and other obsolescent equipment which can impact on a customer's ability to also connect more modern CPE on the same line, or restrict full use of Telecom's network services.

The present conditions published in PTC 100 do not cover the situation where a product does exactly what it was originally intended to do, but does not meet some new requirement that applies to most Telecom customers.

PTC 100: 1987 includes provisions for "expiry" and for "cancellation" of permits. "Expiry" currently applies only where a permit has been granted for a particular batch or time. This does not cover the above cases. "Cancellation" applies where a product does not meet the specification under which it was granted. Again, this does not cover the above cases.

Although PTC 100: 1987 provides for "periodic re-certification", we have not used this provision for many years because most CPE items have a relatively short market life and older products are simply superseded by a newer one within a year or two. Relatively few products are still being marketed 5 years after a Telepermit has been granted. As such, there has so far been little need to press for "sunsetting" devices which do not meet a later PTC specification. We now propose setting a 5-year validity for all Telepermits granted after 1 January 1999. Thus, only the few products with a longer market life (supplier still selling new products of the same design after 5 years) will need to be re-certified.

Rather than introduce another Telepermit category to cover "obsolescence", the conditions for expiry in clause 12.1 have now been expanded to better provide for new developments which impact on earlier types of CPE. An amendment was desirable in any case, as annual re-certification of all permits has not been applied.

The Telepermit system has now been running for almost 11 years and even longer for some much earlier Telecom and Post Office products, which were Telepermitted under "grandfather" arrangements during 1987 - 89. Some of these older products are now not really suitable for use on modern digital networks and may adversely affect the performance of more modern CPE on the same line. This amendment to PTC 100 provides for Telecom to publish advisory information on obsolete CPE, as and when the need arises. Hopefully, this will help to reduce the risk of customers returning new CPE as "faulty" when the only problem is that its performance has been affected by other equipment on the line, such as an old telephone or bellset.

Return to Contents

b. Year 2000 Compliance

In Newsletter No. 106, I mentioned that we were considering making a "Year 2000 compliance statement" a formal Telepermit requirement. The growing public concern about products that might fail and the potential impact of those products on a customer's business bring this issue clearly under the provisions of New Zealand consumer protection legislation.

In the circumstances, and in line with our usual 3 months formal notice of new PTC requirements, I now advise that this WILL become a formal requirement of ALL PTC specifications from 1 January 1999. To avoid amending all PTC specifications, this change will also be dealt with in Amendment No. 1 to specification PTC 100.

Clause 5.3.1 covers the information to be supplied by Applicants. New sub-clauses will be added as shown in the attached amendment.

Return to Contents

c. Harm to the Network

Section 6 of the Telecommunications Act 1987 gives each network operator the right to determine what equipment may be connected to its network. Telecom's practical means of implementing this section of the Act is the Telepermit system. PTC Specifications have been published to advise the CPE industry of the mainly technical requirements that must be met to gain Telecom's agreement to the connection of their products.

In 1987, the primary use of the telephone network was, of course, telephony. Calls were of around 3 minutes average duration and the Telecom network was dimensioned to carry the resultant traffic. Since that time, fax and data traffic has gradually built up to high levels and 1998 now sees very extensive use of the internet. Call durations are increasing and this is impacting on total traffic loadings.

Where any device is designed or used to set up and hold calls continuously, even when actual customer to customer communications are not taking place, the resultant traffic loading is far in excess of "normal" telephone calling. There is no actual traffic and certainly no "ordinary telephone call" taking place in these circumstances. On the other hand, the customer's equipment is holding the line, the Telecom switching facilities and, possibly, one or more inter-exchange junctions, such that they are no longer available to other customers. Widespread use of such devices would either increase overall network provisioning costs (and ultimately lead to increased charges for all other customers), or simply result in unacceptable levels of congestion.

Potential harm to the network and its support systems could arise where any customer equipment is so designed that it causes errors in Telecom's billing information or gives rise to inconsistencies between customer and network data. While this is not physical harm to the actual network, as such, it is obviously not acceptable to Telecom if our customers' perception of our service is impaired or where calls are incorrectly billed. A common example of such a problem is a DDI PABX which does not provide answer signals back to the network. Telecom thus insists that accurate and prompt answer signals are provided by DDI systems in order to correctly bill a call and avoid loss of revenue. Y2K non-compliance raises another possible source of such problems.

This particular issue is covered by a new clause 4.3. In due course, PTC 200 will include additional requirements to cover the above matters from a more technical standpoint.

d. Explanation of amendments

Amendment No. 1 includes some amended definitions and terms, which appear throughout the document. The term "PTC" in relation to permits has been replaced by "Telepermit" to clearly relate the permit to the Telecom network. At this stage, the term "PTC" is retained for consistency with the rest of the text.

Formal test reports have been required since the introduction of the Telepermit system and "Certificates of Compliance" and "Power Certificates" have not been used. Similarly, an "RFI Certificate of Compliance" is no longer sought by Telecom. It is a regulatory requirement that Declarations of Conformity are to be submitted to the Ministry of Commerce

All references to TELARC should now be to IANZ (International Accreditation New Zealand Limited)

The new terms will be inserted in the appropriate places in the next edition. The actual clause changes are as follows:-

Clause 4.3 is amended to provide for any matters which arise in terms of item c Harm to the Network above.

Clause 4.5 is amended to increase the scope of the Telepermit Register entries to cover such aspects as Y2K compliance, obsolescence, etc.

Clause 4.7 is amended to cover the extended range of test laboratories now available.

Clause 4.8 is amended to cover Limited Permit trials.

Clause 4.13 is amended to cover the new "Expiry" conditions and differentiate between "cancellation" and "expiry" as to what a customer may "connect" or "leave connected".

Clause 5.3 is amended to align with the summary of information now required to be submitted with a Telepermit application, as shown on current application forms.

Clause 6.3.2 is amended to set a 5-year term on all new Telepermits granted after 1 January 1999. Annual re-certification will be required for such products still being offered for sale 5 years after the grant of a Telepermit.

Clause 7.5 is amended to cover the need for re-certification of those products still being offered for sale after 5 years.

Clause 8.1 Telecom provide label artwork as a standard procedure, so "where requested to do so" is unnecessary. The wording of the Telepermit label in sub-clause (5) has since been simplified.

Clause 9.4 (3) The Access Standards Newsletter is established as the best means of advising the industry of new and amended PTC requirements.

Clause 11.8 A new clause added to cover Year 2000 compliance requirements, as explained in item b Year 2000 compliance above.

Clause 12.1 is amended to provide for additional expiry conditions, as outlined in item a Expiry and re-certification of Telepermits above.

Return to Contents

EXPIRY OF 3-WIRE HARDWARE TELEPERMITS

In line with the revised Telepermit expiry conditions outlined in item a Expiry and re-certification of Telepermits above, it is now proposed that we take a more positive stance with respect to increasing the use of 2-wiring and actively reducing or avoiding any new 3-wiring. Comments on the following proposals are invited from any interested parties.

Newsletter No 94 of October/November 1996 announced that, from 1 February 1997, 2-wiring would be mandatory for all new installations and additional lines installed in residential premises for that wiring to be maintained by Telecom under its residential premises wiring maintenance service. We strongly recommend that ALL new wiring be 2-wire and that all new cable installed should perform to at least Category 3 (which has Telepermits in the PTC 222/series).

Widespread availability of 2-wire jackpoints took more time than we originally expected, so the original timing was not met in all cases. Nevertheless, the improved performance of 2-wiring in comparison with the earlier 3-wiring system makes continuing with 3-wiring a poor alternative. This is especially the case where the customer needs or is likely to need to run a 56 kbit/s modem or where the line is subjected to electrical noise. Also, if the customer is likely to want Telecom's proposed new ADSL high speed internet service, 2-wiring will be necessary for the maximum benefits of this service to be achieved.

In order to actively phase out 3-wiring, it is now proposed that the following three steps will take place:-

  1. Telepermits for Master jackpoints will expire on 1 April 1999, and
  2. Telepermits for Extension 3-wire jackpoints will expire on 1 January 2000, and
  3. Telecom's current restriction on mixing 2-w and 3-w jackpoints will be removed and replaced with some clear conditions relating to such mixing.

These changes will give suppliers nearly 8 months to clear present stocks of master jacks which, in any case, are not required and should NOT be used for extending an existing installation. A longer period is proposed for suppliers to clear the larger stocks of 3-w extension jacks, which are still widely used for additions to existing 3-w installations. Following their expiry, the only remaining use of 3-w jackpoints for new work will be the few proprietary-wired commercial installations, which have BT-style sockets with more than two wires actually used for signalling and transmission. Such commercial cabling and wiring is not subject to Telepermit requirements in any case.

Telecom was initially concerned at "mixing" 2-w and 3-w jackpoints because of the risk of "Do it Yourself" installers "losing" the third wire and having trouble with 3-w connected CPE not ringing. Another point is that mixing does not help to improve the balance to earth, so the full benefits of 2-wiring are not available. On the other hand, the need to convert fully to 2-wiring was a serious disincentive to anyone wishing to keep costs to a minimum. It is now preferred that we encourage 2-wiring, even if it is only progressive at any individual installation.

The only real drawback to these changes is that the relatively low percentage of customers who do not subscribe to Telecom's wiring maintenance service will be required to convert to 2-wiring should a master jackpoint fail in service. Nevertheless, once they have converted to 2-wiring, they will have a far more reliable and higher performing installation.

It is appreciated that these proposals will reflect into the "standard" wiring instructions supplied with most jackpoint kits and these will be amended progressively. Similarly, these and other related changes will be covered in a new edition of PTC 103.

Return to Contents

TNA 150: Telecom Telephone Network numbering Plan

Issue 3 of this document is now available from Access Standards at a cost of $20, inclusive of postage and GST. In line with our practice since 1996, the new edition is in A4 loose-leaf format, and is supplied without a folder.

This new edition covers developments in the Telecom Numbering Plan which have resulted from discussions in the New Zealand Telecommunications Numbering Advisory Group (NZTNAG) since the last edition was published in 1993. Such issues as number plan expansion, personal and nationwide numbering are included, along with the various numbering arrangements being made to support the many new network and service operators now entering the field.

The Number Allocation Criteria for service access codes, service numbers, etc, which were published in the second edition of TNA 150, are no longer included. Because these rules have been subject to a number of revisions, they are now published in Telecom document Call Charging Steps and Network Numbering", which is also available from Access Standards. This document is revised quarterly.

Return to Contents

DOUG BURRUS

Manager, Access Standards