TELECOM ACCESS STANDARDS NEWSLETTER NO. 87 JANUARY/FEBRUARY 1996 CONTENTS 1. TELEPERMITS GRANTED DURING 1995 2. NEW COMMERCIAL BUILDING CABLING STANDARD 3. "DOMESTIC CALL CHARGING STEPS" - NEW TITLE & REVISED PRICE 4. ELECTRICAL SAFETY TESTING OF CARD AND EXTERNAL MODEMS 5. VOICE MESSAGING SYSTEM STANDARD 6. NEWSLETTER "COPYRIGHT FREEDOM" 7. TELEPERMITS FOR INDIRECTLY CONNECTED CPE 8. ALPHA-NUMERIC KEYPAD MARKINGS RETURN TO MAIN INDEX 1. TELEPERMITS GRANTED DURING 1995 The December Newsletter reported the upsurge in Telepermit applications and grants during 1995, as at mid-December. The full details of these grants is published in the December 31 issue of the Telepermit Register. To avoid inquisitive readers having to calculate the overall totals from the Register, the overall number of Telepermits granted was 606. Of these only 6 were granted to Telecom itself! This is a far cry from 1988, when 152 permits were granted and Telecom got 64 of them. The grand total of Telepermits issued since 1987, when only 15 were granted, stood at 3042 on 31 December. This included 74 Limited Permits still in progress. As far as processing work is concerned, we also handled another 91 items as "extensions" of existing Telepermits - typically for additional feature cards in PABX and other complex systems. Considering that these applications do not form a steady flow and that we also handle internal investigations and studies, client enquiries, specification writing, etc, readers can perhaps appreciate why we recommend that applicants should allow three weeks for processing. We'll do our best to beat this, but it is not always possible. 2. NEW COMMERCIAL BUILDING CABLING STANDARD The publication of AS/NZS 3080:1996 "Telecommunications installations - Integrated communications cabling systems for commercial premises" is getting close now and the new Standard is likely to be available around March-April. Standards New Zealand and its working group members will be running a series of "introductory seminars" for the cabling industry, architects, consultants, and any other interested parties to help launch this as the national standard. As can be seen from the title, it is a joint production with Standards Australia. What is not clear from the title is that it is the "ANZ" version of ISO/IEC 11801:1995, which itself could be described as the "internationalized adaptation" of EIA/TIA 568A, what many regard as the current de facto standard in this country. The actual names and numbers are not critical, but they do indicate the pedigree of the new Standard and the fact that it has international recognition. We are hoping that the new Standard, which aligns with AS 3084 on Pathways and Spaces, AS/NZS 3085 on cabling system administration, and a number of other Australian cabling standards, will be accepted by all parties as the basic guides right through from building design concept stage to in-service cabling management. If this is done, modern commercial buildings are far more likely to meet their occupants' requirements for efficient and reasonably "future-proof" telecommunications services at the lowest practicable costs. Achieving these objectives should increase their rentability and their rentable value. Above all, we need to get this message across to building developers. If they insist that buildings are designed to accommodate the cabling, it should make life easier for all those that currently have to squeeze cables into spaces that were never designed to fit them. 3. "DOMESTIC CALL CHARGING STEPS" - NEW TITLE & REVISED PRICE This quarterly publication originally dealt with details of the geographic locations (place names) that make up our local calling areas and the charging steps that apply to national calls made between each combination of local calling area. The information was used primarily for Call Detail Processor and PABX programming. Over the past few years, the scope of this publication has broadened considerably and it now gives a lot more information on network numbering. For example, it defines the rules for allocating access codes and service codes, as agreed by the New Zealand Telecommunications Numbering Advisory Group (NZTNAG), and publishes the actual allocations of these codes. To better reflect the broadened scope, the publication is now entitled "Call Charging Steps and Network Numbering". The same publication dates apply, but the annual subscription charges are being rounded up to $250 for the paper version and $650 for the software version. Both prices include GST. 4. ELECTRICAL SAFETY TESTING OF CARD AND EXTERNAL MODEMS Last month's article on PC card modems led to some valuable input from two Australian test laboratories, who have been wrestling with similar problems in interpreting the application of AS/NZS 3260 to modems in general, not just card modems. They also pointed out that in 7 (I) (a) of the article, I had made a typographical error in my reference to clause 6.3.2 of AS/NZS 3260. This should have read 6.3.3. I would like to ensure that all safety laboratories testing for Telepermit purposes are using the same interpretations of the basic standard. Since AS/NZS 3260 is common to Australia and New Zealand and many products are intended for both markets, there is benefit in our aligning with Australia as regards detailed interpretations and applications of this standard. This will help meet the objective of one set of tests for both AUSTEL and Telepermit, although it should be noted that Australian test voltages are considerably higher for some of these tests. Uniform and correct interpretation of AS/NZS 3260 by test laboratories is one of the aims of the Electrical Compliance Testing Association of Australia (ECTA), an association of mainly Australian testing laboratories at this stage. They and AUSTEL have also been concerned about the application of AS/NZS 3260 to modems, both card and external types. Based on the information provided to me, the following corrects the article in Newsletter No. 86 and extends it to include external modems. An important point that I did not mention with respect to the full application of clause 6.3.3 of AS/NZS 3260, is that it requires that there shall be "supplementary insulation for a primary circuit" between any protective earth and the telecommunications network connection. Such supplementary insulation requirements are defined in more detail in Section 2 of AS/NZS 3260, which sets minimum creepage and clearance distances and defines the test voltage. Reference to Table 3 shows that for our 230 V system and for the Australian 240 V system the clearance distance for supplementary insulation is to be at least 2 mm. Table 6 then defines the required creepage distance to be 2.5 mm. This is based on 250 V rms working voltage, pollution level 2, and material group III a and IIIb, which is the accepted rating for a printed circuit board surface. In addition, contrary to my "clarification" in Newsletter No. 86, Table 18 requires a test voltage of 1500 V ac rms, not 1 kV ac rms, as I stated. This is because of the presence of the protective earth. The 1 kV test voltage I stated in 7 (I) (b) is thus incorrect. It should remain at 1.5 kV, as per the current PTC specifications. External modems have caused further interpretation problems because, while most are supplied via an ELV plug-pack, they connect to both the telecommunications network and to the PC earth via the RS 232 or equivalent interconnect cable. While they are not strictly "Pluggable Equipment Type A" because they do not connect direct to the 230 V, their functions are essentially the same as those of a card modem. While the earth in the modem cable is essentially a "functional earth" for communications purposes, it is connected to the protective earth of the PC and any other peripheral devices that may also be connected to the same PC. For example, printers are almost always "pluggable equipment type A". These connect their protective earth indirectly to the modem via the PC in the form of signal earth connections within the printer interface cable. These conditions are not specifically dealt with in the standard, but it obviously aims to provide adequate isolation between the local (customer premises) earth and the telecommunications line. The line is, of course, connected to the distant telephone exchange earth. It is important to guard against breakdown when there are differences between the two earth potentials. This implies that the two types of modems should be subjected to the same test requirements. The Australian test laboratories are thus interpreting the requirements in this way. My comment in 7 (iii) about the reduced test voltage for voice/data modems is thus also incorrect and we will retain 1500 V ac rms as the test voltage after all. I trust that this additional explanation will clarify the position for test laboratories who are not yet members of the ECTA and for those modem suppliers who are concerned about the interpretation of safety test specifications. 5. VOICE MESSAGING SYSTEM STANDARD With the rapidly expanding use of voice messaging, voice mail and other interactive voice response systems connected within and to the Telecom network, there have been several requests for some sort of standard customer interface. This applies especially to the DTMF signals used to go "forwards" or "backwards" through the sometimes interminable prompts and options and to the actual organisation of those prompts and options. It is not for Telecom to lay down what procedures are to be used. These decisions are the responsibility of the system designer. Nevertheless, there would be some benefit if all designers could work towards a higher degree of standardisation as regards at least the basic commands. This would help overcome one of the common bugbears of these systems - having to listen to most of the options before making a choice at each stage in the call or going down the wrong track and having trouble getting back to the right one. These voice systems are encountered on international circuits and there could be a lot of benefit in a higher degree of international standardisation. This would help where callers are not familiar with the prompts used, especially where they are encountering other languages than their own. With these problems in mind, the two main international standards organisations have jointly published their Standard ISO/IEC 13714: 1995, which is now available from Standards New Zealand. It is not yet a New Zealand Standard, but it does set out some general rules which could be more widely applied here. For reference, its full title is "Information technology - Document processing and related communication - User interface to telephone-based services - Voice messaging applications". Some of the key points of this Standard are the use of DTMF only (no decadic support) and mandatory support for "Dial through". This is a facility especially suitable for regular users in that they can dial the necessary DTMF digit without having to wait for an option message to be completed. "Dial ahead" is another useful, but optional facility, whereby the regular users can choose to dial the full digit string necessary to route them through the system without waiting for any of the options. More importantly, the "#" signal is always used as the de-limiter to complete input signalling without using a delay or time-out at the end of the required input. The response system then steps on to the next stage. The "*" signal is always used to revert back to the control menu. Digit "7" is used to "skip backward" and digit "9" is used to "skip forward". The Standard also specifies a tone sequence to be used as the indication that the system is ready to record an incoming message. Obviously, there is a lot more detail in the 60-page Standard, but the above are some of the key points of the standardised system. The document is available from Standards New Zealand at prices, inclusive of GST, of $183.77 to members and $229.71 to non-members. Any readers who would be interested in taking part in a Working Group to study the Standard and consider its adoption as a New Zealand Standard are invited to telephone Nelson Procter of Standards New Zealand on (04) 495 0928. 6. NEWSLETTER "COPYRIGHT FREEDOM" I should remind readers that we regard these Newsletters as "Copyright Free" in that we invite (and welcome) copying to other parties. This includes overseas principles, local staff and branch offices, distributors, retailers, etc. A number of recent articles have dealt with issues of interest to retailers in their dealings with customers. The possible implications of incompatible "mixing and matching CPE and Telecom services" was one example of this. I strongly recommend that Telepermit holders pass this sort of information on to their retailers, as some appreciation of the problems could avoid them getting involved with unnecessary product returns or warranty claims. Needless to say, if retailers can help customers avoid "apparent" faults, this will help Telecom too. In a similar vein, I often cover potential problem issues so that they can be avoided at the design stage. Here again, getting this information to the overseas manufacturer may result in simple low-cost changes that save a lot of time, cost and effort in the long run. 7. TELEPERMITS FOR INDIRECTLY CONNECTED CPE Another reminder. Those products which, although connected behind other CPE, can affect the overall transmission or signalling interface with the Telecom network DO need a Telepermit. Typical examples are the terminal equipment connected behind a PABX and overall "systems" such as voice mail, which are "wrapped around" a Telepermitted interface card. 8. ALPHA-NUMERIC KEYPAD MARKINGS As mentioned in Newsletter No. 86, more and more CPE now incorporates the new markings and there is increasing use of alpha "numbers" for 0800 services. In line with the international decision to support the new keypad markings from April, Telecom is planning to promote the use of 0800 alpha-numerics within the next few months. Our approach will, of course, be based on the new standard letter/digit allocations. This promotion will make customers more conscious of the need for alpha markings on their keypads. No doubt demand for the "proper" markings will increase as a result. As I advised in Newsletter No. 80, in view of the slow take-up overseas, I have been considering an extension of the time by which the new markings will be mandatory. As published in the "Draft for Public Comment" of PTC 202, Issue 2, the new markings were to be mandatory on 1 April. While some progress is obviously being made, many local importers and agents have indicated that their manufacturers are reluctant to make changes only for the relatively small orders being received for the New Zealand market. Keypad markings are obviously not a "make or break" issue for network compatibility and we want to ensure that our PTC requirements are not unreasonable. I now propose that we drop the mandatory compliance requirement for the present. This will give suppliers more time to comply and put more emphasis on "market demand" to encourage adoption of the new layout. Unless there are any strong objections to this, the change will be incorporated into PTC 200 when it is published to replace PTC 202 draft. The compliance position will be kept under review in the light of overseas trends and decisions. Needless to say, we still strongly recommend that products with the "Q" and "Z" on digit "1" of the keypad be phased out at the earliest opportunity because this layout is clearly misleading. With promotion of alpha use, products with the new standard markings are even more likely to have a marketing advantage over those that have either no letters or the wrong letter allocations. Introduction of the new markings is thus STRONGLY recommended for new products and for those which already have Telepermits " DOUG BURRUS Manager Access Standards