TELECOM ACCESS STANDARDS NEWSLETTER NO. 92 JULY/AUGUST 1996 CONTENTS 1. PUBLICATION OF TNA 151 2. TNA 102 AND PTC 200 AMENDMENTS 3. RINGING DURATIONS 4. RINGING DECODERS AND CADENCE TOLERANCES 5. WITHDRAWAL OF SUPPORT FOR DECADIC SIGNALLING 6. CALL CONTROL SERVICE 7. CONNECTION OF SECURITY ALARMS TO PABX SYSTEMS 8. PRODUCT FUNCTIONS AND CAPABILITIES 9. ENQUIRIES ABOUT TELEPERMITS AND APPLICATIONS 10. COLOUR PHOTOGRAPHS 11. HEARING AID COMPATIBILITY SYMBOL RETURN TO MAIN INDEX 1. PUBLICATION OF TNA 151 TNA 151, our specification and description of the Telecom PSTN Transmission Plan has just been revised to cover developments since the 1990 edition was published. This 1996 version is now available from Access Standards at a price of $50, inclusive of postage and GST. This edition is in our new A4 loose-leaf format, supplied without a binder. For those who do not yet have one of our white binders, these can be supplied at a price of $15 inclusive of postage and GST. The new plan was the basis for the transmission aspects of the recently published PTC 200 and TNA 102, especially as regards the revised Loudness Ratings quoted in those specifications and originally published as the draft for public comment of PTC 202 in December 1994. It is not directly relevant to CPE suppliers, who will get the information they need from PTC 200. However, TNA 151 is published as general background information on Telecom's network for those readers who want to know more about the overall network design. 2. TNA 102 AND PTC 200 AMENDMENTS Our thanks are extended to those readers who have pointed out discrepancies or errors in these two specifications. I am pleased to report that few errors have been found but, as expected, the world is moving on at a rapid pace and there is already a need for some amendments to cover proposed network developments. These will be published as Amendment No 1 to each specification in the next month or so. In the meantime, one change will be of interest to many CPE suppliers. This relates to the extension of ringing durations beyond the current 15 seconds maximum. 3. RINGING DURATIONS The maximum permissible answering delay for auto-answering CPE is now increased to 30 seconds. The minimum delay of 3 seconds for products in general is unaffected although we will still permit faster answering where justified (see PTC 200, clause 8.2). With customers connecting more and more CPE to their lines, the problems of "call types" and "answering sequence" can get quite complicated. "FaxAbility" provides the most certain way of discriminating between types of calls, but not all of our exchanges can offer this service. Where it is used, fax answer times can generally be reduced to one cadence of ringing. While not all customers can have "FaxAbility", Telecom's "Dual Number" and "Call Minder" services are available to almost all of our customers. These provide for a customer to select one number for voice use and the other number for fax/data, with only the voice number diverting to "Call Minder". The increase to 30 seconds covers the combination of auto-answering CPE with these network services. With the extra time, customers will be able to set up their answering arrangements to better discriminate between voice and data incoming calls. If calls to the "voice number" are diverted after a pre-set number of rings to a service like Call Minder, the remaining calls can be answered by the fax machine or modem with the knowledge that they must have been to the "second number". Even without these network services, the extended auto-answer duration gives customers more time to answer a telephone before a fax machine takes over. This should help reduce the frustration for a telephone caller who keeps encountering a fax machine and for the customer who cannot answer before the fax "takes over". The key issue is that customers should consider the time likely to be needed to answer the phone and then set the auto-answer device accordingly. We still regard 15 seconds as the "preferred" maximum answer delay, as this is "friendlier" to callers. There is always the risk that extending ringing beyond 5 or 6 ringing cadences will result in the caller giving up before any switching takes place. We thus require that auto-answer CPE be supplied with a default value of between 3 and 15 seconds, so that customers will extend the value only where it is necessary to do so. As mentioned above, this change will be covered by the proposed Amendment No. 1 to PTC 200. 4. RINGING DECODERS AND CADENCE TOLERANCES As mentioned in Newsletters 85, 88 and 91, ringing decoders need to allow for potential cadence distortion under some network conditions. Our PTC requirements specified that decoders should tolerate ±10% distortion, which results in an "on" period of anything from 360 - 440 ms. However, this range may be exceeded on a small percentage of Telecom lines. This situation arises due to the use of network reticulation systems which were not designed to accurately repeat coded ringing. Coded ringing was widely used in the "early days", usually for party line applications, where a human listener had tremendous flexibility to recognise codes no matter whether they were accurate or otherwise. Many of our network transmission systems were designed either before distinctive alerts needed to be catered for , or in overseas countries, where there is no need to repeat ringing codes accurately. Because electronic decoders cannot be expected to have the same degree of flexibility as the human ear, we have to face up to the fact that they may not work on some of these lines. In view of this situation, we are setting up a database to determine which of those NEAX 61E customers are served by transmission equipment which would exceed the ± 10% "ON" period tolerance. These customers will be warned that "FaxAbility" and any other services dependent on Distinctive Alerts are unlikely to be successful with CPE intended to automatically determine the specific DA code. 5. WITHDRAWAL OF SUPPORT FOR DECADIC SIGNALLING Telecom intends to progressively withdraw support for decadic signalling in its network, such that most new services are likely to be "DTMF only". While most new network services and features will require DTMF signalling CPE to access and control them, there will be some exceptions. Examples are the over-ride codes for restricting or displaying a calling number under our Caller Display service, which is expected to be introduced during August. To comply with the Privacy Act, customers need to be able to control the display of their numbers where their lines provide a control feature and display is not always blocked by the network. Telephones and other CPE have been predominantly DTMF for many years now, but there are some decadic signalling products still being sold. Suppliers of these products are advised to avoid purchasing further shipments of such decadic designs now that a decision has been made to withdraw network support for them. 6. CALL CONTROL SERVICE Towards the end of this year Telecom expects to be introducing a new DTMF-only service on its NEAX 61E exchanges. This will allow customers to be provided with a high level of control of calling from their lines, coupled with monthly telephone accounts sorted according to the customer's particular needs. Those customers taking the service will hear a prompt to insert one of a pre-arranged set of control numbers after dialling the wanted number. These control numbers can be selected to correspond with individual callers (as in a small business or multi-tenant flat situation) or according to particular client accounts (as with legal and other professional service providers). Telecom's monthly bills will be formatted according to the account or person associated with the control number used by the caller. The caller will also be able to arrange for an optional over-ride of the control number and simply dial "#" or await a time-out when it is not required for accounting or other purposes. Service calls, such as those to "123", "126" and "111" will not need a control number to be inserted. This new service will be optional. It is not a "default" service provided to ALL customers. This "early warning" is provided to advise CPE suppliers, alarm system suppliers and any other interested parties of the potential impact of this service on their products should their customers elect to subscribe to this service. Any auto-dialling products, such as memory telephones, fax machines, alarm diallers, and any other automatic calling devices connected to lines with this service will need to be set up to meet the calling conditions chosen by the customer. Typically, it will be necessary to introduce a pause after the called number and then input one of the pre-arranged control numbers for the line concerned. In practical terms, a one to two second pause after the wanted number should be adequate, as the CPE can "dial through" a prompt. Control numbers can be up to 5 digits in length, as selected by the customer. This means that the digit capacity of an auto- calling device used with this service may have to be sufficient to cope with an international number, plus any pauses (which also count as digits on many products), plus the control number. Needless to say, it will be necessary for Telecom to liaise closely with a customer as regards the types of CPE connected and any set-up modifications if we are to avoid "locking out" their auto-calling equipment. Auto-calling alarm systems are of particular concern, as prospective customers will need to advise their alarm monitoring service and have changes made before subscribing to the service. A further complication is that many alarm diallers may not have the capability to work with this system. While the new service is likely to be of assistance to many customers as an alternative to a call detail recorder, a recorder will still be required where call charges need to be determined promptly without passing calls via Telecom's "Price Required" services. Telecom will be publishing further details of the new service closer to launch date. 7. CONNECTION OF SECURITY ALARMS TO PABX SYSTEMS The connection of security alarms in business premises is likely to also involve connection to a PABX system. A recent case brought to light the fact that the alarm company had connected via extension cabling such that the alarm dialled out through the PABX. This is a choice for the customer and the alarm supplier, but it could prove a problem if the PABX loses power or the extension concerned goes out of service for some reason. 8. PRODUCT FUNCTIONS AND CAPABILITIES Telepermit applicants are reminded of the need to describe the functions and capabilities of their products when applying for a Telepermit. While this may sometimes seem unnecessary, it is important that the test laboratories are aware of any features which are likely to affect compliance with network specifications. They can then ensure that the necessary tests are carried out and we confirm that all is well. Similarly, it is important that we do not overlook features which are likely to cause problems when the product concerned is connected to the network. As such, "full disclosure" is in the best interests of suppliers and should help to avoid unnecessary product returns or claims that a product is unsuitable for the customer's intended purpose. 9. ENQUIRIES ABOUT TELEPERMITS AND APPLICATIONS As advised back in 1993, we briefly check over the completeness of Telepermit application submissions and acknowledge receipt of the application within a day or so of its arrival in our office. Each acknowledgement is allocated a sequence number in the format "year/sequence number for that year". For example, "96/256". This is shown on the form we fax back to the applicant. Enquirers will help us give them a prompt reply to any queries if this Application Number is quoted with the enquiry. To ensure papers are filed with the right application, this number should also be shown when an applicant is sending additional information as part of a submission. Once a Telepermit has been granted, the Telepermit number should always be quoted when making enquiries or providing back-up information. As will be seen from the Telepermit Register, there are over 3 000 products now Telepermitted and there are many with very similar sounding names. In fact, there is nothing in our system that prevents two or more suppliers using the same product name. Please help us to help you in making sure papers do not get associated with someone else's product. 10. COLOUR PHOTOGRAPHS AND BROCHURES Applicants are reminded of the need to supply colour photographs or colour copies of the original photographs of their products. These should be in sufficient detail for us to be able to recognise that the product offered for sale is identical to the sample that was shown to be compliant with our PTC specifications. Monochrome photographs and copies are NOT acceptable for Telepermit purposes. Brochures are also requested, as these allow us to cross-check the test reports with the features offered, as explained in item 8 above. With products and network services becoming ever more complex, the risk of incompatibilities is also growing. Obviously, our immediate aim is to reduce the problems faced by our service staff, but it is also in the best interests of CPE suppliers and their retailers that incompatibilities be avoided wherever possible. 11. HEARING AID COMPATIBILITY SYMBOL In Newsletter No. 89, I explained the use of the international "Ear" symbol to indicate the compatibility of telephone devices with the "T switch" on most hearing aids. My intention was that this symbol would generally be marked at the receiver end of the telephone handset, where it can be seen by a user as the handset is raised. It has since been suggested that the symbol could be incorporated into the Telepermit label to avoid having too many additional markings and labels on a product. This would be entirely acceptable to Telecom, but there is the disadvantage that the Telepermit label is usually tucked away underneath a telephone and not easily seen. Another minor problem is that the "official" colour of the symbol is blue, rather than the usual green of our Telepermit labels. From our viewpoint, it would be better to have the facility marked somewhere on the phone rather than not at all, even if it is the wrong colour and not immediately obvious. DOUG BURRUS Manager Access Standards