Whirlpool

Whirlpool RIM and Pair Gain FAQ - v3.1
6 January 2004 - Last Updated 2 February, 2004

This FAQ contains information on RIM and other Pair Gain technologies used throughout the Australian telecommunications network. Pair Gain systems are barriers to ADSL availability and this resource is designed to help inform users what they're connected to and what they can do about it.

This FAQ was written by Brett H.

If you have anything to discuss regarding this FAQ or any further questions, please post a reply to this thread.

1. Introduction
2. Credits
3. Disclaimer
4. RIM - Remote Integrated Multiplexer
5. CMUX - The Successor to RIM
6. PGS - Pair Gain Systems
6.4 Obsolete Pair Gain Systems
7. Loading Coils and SLEs
8. Can I get ADSL on my RIM/Pair Gain?
9. What are Telstra's plans for upgrading my RIM/PGS?
10. What can I do about being on a RIM/PGS?
11. More Information

Introduction

Welcome to the Whirlpool RIM and Pair Gain FAQ Version 3.0

This version of the Whirlpool RIM and Pair Gain FAQ replaces the old one, now with more pictures, more detail, and more tips.

This FAQ has put RIMs and �other pair gain� systems in two different categories, though technically they are both forms of pair gain. RIM is more likely to affect Whirlpool members than the other systems (at least from my experience) and thus more information is provided about RIM than the other systems and giving RIM its own section is a result of this.

I would like to say that I am quite proud of what we as a community have been able to achieve here. When compared to other Broadband user sites, it would appear as though the information we have on our country�s telephone infrastructure vastly exceeds most.

That said, I never really wanted to learn a lot of this stuff, though look at what Telstra made me do � and all I wanted was an ADSL connection.

Please remember that most telephone companies around the world utilize pair gain technologies to service some customers � it�s a matter of economics and being pressed to have services available as soon as possible. It�s definitely not illegal for Telstra to provide your phone service over a pair gain system, nor is it illegal for them to charge you the full line rental for a pair gained service. You may feel cheated indeed, especially after you realize that your dial-up speed and ADSL prospects may be degraded, though please remember � you are paying Telstra for a voice grade service and that�s what you�re getting � a perfectly fine analogue voice line to your exclusive use. Prior to electronic pair gain networks, you would probably have been allocated shared use of a party line! Please also note, that while you feel cheated paying full line rental on a pair gain line � the line quality of the bearer that serves pair gain systems typically has to be much higher, unloaded, etc. etc. in addition to extra maintenance and upgrade costs.

Much of the copper network is 30+ years old and it�s not easy to continually do upgrades to it and still remain profitable. It�s not a matter of simply running new cabling � you have to consider effects on traffic and pedestrian movement, cost of trenching, environmental effects, etc. Trenching over about 100m usually requires council approval � another headache that Telstra would like to avoid.

Pictures are hosted on my Gateway on CairnsNet bandwidth (I thank Gary S. for turning a blind eye to the �no servers� policy), and may be a little slow to load (yes, I�m a RIM victim) as the connection normally only offers 64Kbit upstream. I don�t wish to put them on another server at this point, so please, just be patient. The server may occasionally be down, if so, try again later.

If this FAQ has helped you, feel free to whim your comments to me.

Credits

This FAQ was written by Brett H. with input from the whirlpool community and information from various sources. Special thanks goes to the Telstra employees and other persons familiar with the technology for helping the “broadbandless” to understand their predicament, and for helping me “debug” this and older versions of the FAQ.

Pictures of the SCaDS RU and the Loading Coils were provded by Magilla Guerilla.

Most other pictures are from either myself or from unknown/uncredited and a few anonymous sources via email.

If I have used a picture of yours and you would like credit for it, please whim me! If you would prefer me not to use it – that’s fine too, but remember – it’s for the benefit of the community and I gain nothing from it (except lag).

I would like to personally thank Devil CV8, Magilla Guerilla., Bayboy, Drekkus and Telco Linesman (in no particular order) for their help in making this FAQ as comprehensive as it is. If there’s anyone I’ve left out, please feel free to whim me and I’ll add you in.

Disclaimer

Information for this FAQ was obtained from a number of sources, including ex-employees of Telstra as well as Telstra's own official statements before the Senate Estimates Committee as well as my old friend google.com. Whilst every care has been taken to ensure this FAQ is accurate, the author(s) disclaim(s) any responsibility for the accuracy of information contained herein. This information is provided for educational purposes only (really – there’s not much else you can use it for!) and it is hoped you will at least understand what you’re connected to and what your options are if you are knocked back for ADSL due to Pair Gain equipment.

Some of the options presented will obviously cost money and may not return the results you want. Please remember that before going ahead.

RIM - Remote Integrated Multiplexer

What is a RIM?

A RIM, otherwise known as a Remote Integrated Multiplexer, is a device that Telstra uses to provision telephone services in areas where there is no existing copper, or the existing copper in the ground cannot support the demand for services in the area.

RIMs are a fairly modern and flexible Pair Gain system designed mainly for urban areas in cities due to their ability to multiplex a large number of lines. RIM units were the successor to the DCS20 and RCM systems deployed before them (more information on these is later in the FAQ).

RIM capacities are split into two groups, one with 120 POTS services as standard, with a maximum of 180 POTS and another with 240 POTS standard, with 480 POTS maximum. The 480-line RIM seems to be the most popular.

Virtually all newer housing estates have telephone services supplied by a RIM. Large office buildings, shopping centres, apartment complexes and the like are all "prime candidates" to be served by RIMs.

In rural and remote areas, older telephone exchanges can often be replaced by a RIM unit that utilizes the existing fibre infrastructure to communicate to an exchange of a larger community.

RIM-type systems are not unique to Australia. In other parts of the world, similar equipment is known as a “Digital Loop Carrier” or DLC. In the USA, a common form of DLC uses a T1 line (24x64Kbps+1x8Kbps) which can be used to provide 24+ voice circuits from one 4-wire phone cable. Other forms exist, however.

RIMs are made by Alcatel.

How are they Used?

RIMs, like all pair gain technologies, require a Remote Unit and an Exchange Unit. The Exchange Unit (as the name implies) provides an interface between the exchange and the RIM via the media in between. The Remote Unit is where the customer connections join the multiplexer.

The media between the EU and the RU can be either Optic Fibre cable or Microwave radio. Optic Fibre is typically used in urban areas, where a radio system would be more ideal to connect a RIM installed on an Island, for example.

Physical Aspects

RIM can be installed in an above-ground footpath-mounted housing, a below-ground footpath housing (discontinued) or in a small exchange building/hut. RIM can also be installed in other areas too � communications centres/wiring rooms for shopping centres and apartment buildings.

Of these, the above-ground footpath-mounted version is the most visible.
There have been three generations of the Above Ground RIM housing.

This is a first generation housing:
www.ceren-networks.com/whirlpool/irim.jpg

This is a second generation housing:
www.ceren-networks.com/w...im-ca40-whto.jpg

This is a third generation housing:
www.ceren-networks.com/w...ta-ca101-rim.jpg
ic.ausgamers.com/rim.gif

ALL footpath-mounted versions should look like this. If yours doesn�t � it�s probably not a RIM.

Why are they used?

Principally, RIM units are used because using them to provision services costs significantly less than traditional copper lines all the way from the exchange. For an estate 5KM from the nearest exchange with 200 houses in it, the sums might end up being 300 lines run for 5KM - and that's a lot of cable and a lot of expense compared to a single fibre run and short copper lengths from the RIM to the subscriber. To run that extra copper, Telstra would need to consider things like cost of the copper, consumption of the duct space (which is very limited and very expensive), labour to install, timeframe to provision services, existing infrastructure, etc. Often, if you are more than a few kilometers from an exchange running more copper becomes incredibly expensive and RIM is the only way to provide services economically.

RIMs allow Telstra to provision services quickly to satisfy rapid growth in new areas and to provide relief in high demand areas within timeframes specified by the Customer Service Guarantee.

Another reason RIM units are used is because a telephone line's quality degrades the longer the distance it is from the exchange. A RIM essentially "brings the exchange" closer to the customer and in some cases gives the customer a better quality voice line than they would have had using a straight copper pair to the exchange.

Deploying RIMs has all but ended these days in favor of CMUX units.

Integrated vs. Non-Integrated RIMs

Some RIM units are configured differently than others at the exchange end, and this will make a difference to the dial-up speed obtained over a line served by the RIM. An Integrated RIM will provide 56K connection speeds, whilst a Non-Integrated RIM will provide 28.8k-31.2k speeds.

It is interesting to note that there is no way to tell an I-RIM and an NI-RIM apart just by looking at them. The difference is at the exchange end (the way the RIM is "integrated" into the exchange). That said, NI-RIM configurations were slightly more common in the earlier days of RIM deployment than I-RIM configurations.

All Integrated RIMs require the first panel installed in the RIM to be non-integrated. The Non-Integrated panel is used for services that cannot be integrated, i.e. ISDN and other special services (SecuriTel, Payphones, etc).

Why are NI-RIM dialup connections slower than I-RIM dialup connections?

For those of you wanting to know why a NI-RIM only provides a 28.8kbps connection, here's the explanation.

There's one thing you need to know. Converting analogue to digital in a phone network is BAD NEWS for modems. With this point in mind, let's continue.

Back at the exchange, the RIM Exchange Unit will do one of two things. Either it will plug straight into the switching backbone of the exchange, or it will connect to distribution frame which breaks out all 480 lines as separate copper pairs again. The first configuration is what is done for Integrated RIMs, the second is NON-Integrated.

For an Integrated RIM, the "journey" ends here. The phone calls are switched directly via the switching gear in the exchange, routed via other exchanges, etc. etc. For a non-integrated RIM, there's a little bit more action to happen yet.

The 480 lines that break out from the NI-RIM at the exchange are terminated onto a little main distribution frame block.

Also inside the exchange are the line interface cards that service lucky people with "clean copper" phone lines. These also terminate on an MDF.

What is done with a NI-RIM, is to run a jumper wire between a pair on the exchange MDF and the NI-RIM MDF. This connects a copper pair from the RIM to a line interface board in the exchange. From the exchange MDF runs another piece of copper which terminates on a line interface board, which is then connected to the switching gear.

Image: www.ceren-networks.com/w...rim_exchange.jpg

From a signal perspective:

From the ISP to the Customer

Your data leaves the ISP in digital form (Often a Primary Rate ISDN line) and travels onto the phone network, through to your local exchange. At your local exchange, your Line Interface board converts the digital signal from your ISP into analogue. This analogue signal is then sent down the jumper wire to the exchange unit of the NI-RIM.

The exchange unit of the NI-RIM converts the analogue signal back to digital (this is bad, remember?) and sends it down the optical fibre line, to the RIM unit itself. Inside the RIM, the digital signal is converted back to analogue and sent down your phone line.

The reason the NI-RIM connects you at 28.8K is because a 56K modem relies on the mostly-digital aspect of the phone network. If you have *any* analogue -> digital conversions between you and the ISP, it kills your speed to 28.8K (or less, depending on number of conversions). The NI-RIM has an analogue to digital conversion between the LI board at the exchange and the Exchange Unit of the NI-RIM.

This does not happen in an Integrated RIM (the digital signals patch directly into the network).

CMUX � The Successor to RIM

CMUX (Customer Multiplexer) is the latest and greatest form of Pair Gain system that Telstra is deploying in place of RIMs.

The CMUX units are a multipurpose device � they provide both narrowband and broadband ADSL access to subscribers. CMUX is still very new and the rollout limited, though it is progressing.

The Mini-CMUX is related to the CMUX unit and is designed for installation in RIM cabinets to provide ADSL capability to subscribers. The Mini-CMUX unit supports two cards, each card supports 12 ADSL subscribers. There can be a maximum of 2 Mini-CMUX panels in each RIM, making a maximum of 48 customers who are able to be serviced.

New - Added 1/2/2004

A RIM with a Mini-CMUX (aka Minimux) will have a 5-letter code in addition to the 4-letter cabinet code that exists on all RIMs.

Here's what to look for to tell if a RIM has been upgraded.

1. The 4 letter exchange code
2. The 5 letter "CMUX" code
3. The Cabinet or Pillar number (CAXX)

www.ceren-networks.com/w...lha-upgraded.jpg
www.ceren-networks.com/w...npa-upgraded.jpg

The above pictures are of 3rd generation RIM housings. I have personally seen a first generation RIM upgraded, so I know that those are able to accomodate it as well.

New - Added 1/2/2004

I now have pictures of the CMUX above ground housing:
www.ceren-networks.com/w...ca10-elija-2.jpg
www.ceren-networks.com/w...x-ca10-elija.jpg

Notice that it is very similar in style to the Third Generation RIM housing. Note however the 5-letter code on the front, plus the ventilation slots at the top which are not present on the RIM housing.

Pair Gain Systems

What is Pair Gain?

More accurately, this section deals with “Small” pair gain services. RIMs are another form of Pair Gain, though their implementation makes them more like a DSLAM-less mini-exchange as opposed to a smaller electronic pair gain system.

These kinds of services are used in areas where immediate relief of the copper network is needed (such as to install a new line under the customer service guarantee provisions) and no available copper infrastructure exists.

How does Pair Gain work?

Pair gain typically takes one or more phone lines and provides more subscriber services than there are actually lines. I.e. one line, 4 services, 6 lines, 16 services, etc.

All Pair Gain systems (as mentioned earlier) have an “Exchange Unit” and a “Remote Unit” and some sort of media in between, often copper or fibre. The exchange unit is the parent of the Pair Gain system and provides demultiplexing facilities and patches them back into the exchange switching system. The Remote Unit is often placed in a pit or pole and provides the connections to customers.

Types of Pair Gain Services and Effect on Dial-Up Speed and Broadband

2DPGS - Two Channel Digital Pair Gain System

2-channel Digital Pair Gain System was the successor to the old FM1+1 system. 2DPGS provides 2 subscriber services from one unloaded, clean copper loop. 2DPGS services aren�t quite as common in metro areas as they are in rural/regional areas. Usually 2DPGS won�t be provided where a large demand for services exists � it would be more economical to provide a larger capacity system.

Dial-Up speed is a bit slow, around 26Kbps for each subscriber. 2DPGS can reach a fair distance from exchange with a repeater, thus at the outer edge of reach it may provide a better service than a non-PGS service.

I have heard of no Whirlpool member on 2DPGS (doesn�t mean there aren�t any � just none that I�ve heard of)

4DPGS - Four Channel Digital Pair Gain System

Essentially the Big Brother of the 2DPGS, provides for four customers off one copper pair. Not generally used these days as the systems provide horrible dial-up modem speeds of around 9.6-14.4kbit/sec. If they are deployed, it is generally done in rural areas and only in exceptional circumstances where a service that isn�t quite as degrading to customers data speed is not suitable.

In a 4DPGS, two of the channels can be bridged to provide 28.8Kbit/sec data speed, though this effectively negates any benefit of having the 4DPGS in the first place.

I have heard of no Whirlpool member on 4DPGS.

SCaDS � Small Capacity Distributed System (SCaDS)

SCaDS was one of the earlier fibre-fed Pair Gains systems, usually deployed in rural areas and to serve remote customers. There is a maximum of 30 customers per SCaDS run. SCaDS is an interesting system because it can be dropped in a single bundle of 30 customers, or daisy chained from one Remote Unit to another providing X customers per drop, up to the system maximum of 30. X is any multiple of 5 less than 30. (i.e. 5, 10, 15, 20).

Dial-Up on SCADS is a bit slow � 26Kbps is what you can expect.

Below is an image of a SCaDS Remote Unit
Image: www.ceren-networks.com/whirlpool/scads.jpg

SCaDS can be configured to provide ISDN or POTS services. Maguilla Guerilla (who took the photo above) said that this SCaDS unit was adjacent to a RCM unit. The copper output from the SCaDS RU connected to the cross-connect on the RCM cabinet, though no services were connected to it. He assumed that the SCaDS unit was there to provide ISDN services, since the RCM cannot do ISDN.

I have heard of Whirlpool customers on SCaDS (I think he was around Mt. Tamborine on the Gold Coast, QLD).

DCS20 - Digital Concentrator System

DCS20 and RCM are typically not distinguishable from their housing alone. DCS20 units are similar to RCM, though provide for greater capacity.

DCS20 supports a maximum of 128 customers per unit, 4 units can be daisy-chained allowing 4x 128 in total. Typically fed by copper (2Mbit/s) or fibre, and provides dial-up speed of around 26Kbit/sec. DCS20 doesn�t support ADSL or ISDN. Similar to RCM in many regards. Manufactured by TeleData.

I have heard of a whirlpool member on a DCS20 system. He provided the pictures below, but I have unfortunately lost his email address, so I cannot credit him with taking them.

Images:

www.ceren-networks.com/w...pool/DCS20_1.jpg
www.ceren-networks.com/w...pool/DCS20_2.jpg
www.ceren-networks.com/w...pool/DCS20_3.jpg

Notice that the DCS20 housing is identical to the RCM housing.

RCM - Remote Customer Multiplexer

RCMs were used mostly in metro areas (though rural applications were also used) to provide relief or new services to an area before RIM existed. I don�t have hard figures, but I would assume (an educated guess) that RCMs would have been popular from about 1988 through to about 1993 when RIM was launched.

RCM is similar to DCS20 and shares the same housing. Each RCM panel can accommodate 6 RCM panels, though only 4 are used due to heat and other environmental considerations. If the RCM is fed by fibre, an additional OptoMux panel will be present to interface with the fibre.

RCMs typically fed by 2Mbit/sec fibre (per access panel) though copper bearers exist. When copper bearers are used, the copper becomes a digital bearer with two pairs per panel � one for send, one for receive. Repeats are placed along the copper line at intervals of about 2KM. Each RCM access panel can serve 3 customers per card with a maximum of 10 cards per panel (30 customers per panel maximum). A fully loaded RCM (4 access panels) would serve 120 customers with 8Mbit/sec backhaul to the exchange.

Dial-up speed isn�t too good, at around 28.8Kbit/sec. RCMs do not support ISDN.

I have heard of a whirlpool member (and half my neighborhood) on a RCM system.

RCM installed in a suburban housing estate:
www.ceren-networks.com/whirlpool/rcm.jpg

DRCS - Digital Radio Concentrator System

DRCS is a very old line concentrating Digital radio system, and whilst a lot better than the previous ARCS systems (you guessed it, Analogue Radio Concentrator System), it�s still quite bad for anything other than ordinary telephone service. Usually fed by VHF radio, it provides 15 �channels� (timeslots) for outgoing and incoming calls. Calls between customers on a DRCS that don�t use one of these �external� channels aren�t included in the call count. From memory DRCS can service 128 customers. Typically installed in very remote areas where demand for modern data technologies is probably low anyway. No ADSL, No ISDN. DRCS generally provides miserable Dial-Up speeds (not quite sure on the exact figure).

DRCS is now mostly obsolete.

I have heard of a customer in the Daintree Rainforest who was on a DRCS system. He is now on an Integrated RIM. (I�ve never seen anyone so excited at 56K modem speeds).

RAM - Rural Access Multiplexer

RAM is generally used (as the name would suggest) in rural applications, and provides 8 customers from 2 copper pairs. ISDN is supported (though it apparently really messes up the 1:4 ratio of the system). Typical dial-up speeds are around 28.8Kbit/sec. No ADSL. Made by Extel.

I know of one whirlpool member on a RAM system in Monto, QLD. He reports stable, but slow dial-up service.

6x16 and 16x96

6x16 and 16x96 known as contention-based pair gains systems, so called because customers must "contend" for trunk lines. They have 6 copper pairs to service 16 customers or 16 copper pairs to service 96 customers. Dial-Up service is reputed to be good, since the line is merely �switched� through to the customer.

To work, the 6x16/16x96 systems rely on customers having low call volumes or short calls, to minimize the chances of all trunk lines on the system becoming busy at one time. If all trunk lines are busy, no more calls can take place. PGS user receives �local busy� instead of dial-tone. Telstra monitors this carefully, and if too many �line campers� take up residence on a 6x16 or 16x96, Telstra will be forced to upgrade it to a non-blocking system, possibly at the detriment of user�s Internet/data speed.

Note: In a 6x16, only 5 trunks are available for actual calls. The last copper line is used for signaling and power. Initially, not all ports on the system are used in order to avoid congestion.

Analogue NT-1

An Analogue NT-1 is normally installed in a residence that already has one clean copper telephone line and requires a second line. It is a modified ISDN line.

The NT-1 receives two 64Kbps bearer channels and one 16kbps Data channel (2B+D) standard Basic Rate ISDN service. It has a built-in terminal adapter equipment to service two analogue phone lines. It requires 240v mains power to function, though if 240v is lost, one of the lines will still operate (line designated as priority line).

As a �bonus�, it provides EXCELLENT dial-up speeds, since the analogue part of the loop runs from the ANT-1 to the modem and may be only a meter or so long. However, since the ISDN signaling system (2B1Q) is incompatible with ADSL, ADSL cannot be provided over the line whilst the ANT-1 is in place.

The old FAQ used to consider A-NT1 as a non-PGS technology, though it really is and has now been added to its rightful place.

NOTE: Telstra is now reportedly removing Analogue NT-1�s though you must request it done. Analogue NT-1 removal is still no guarantee of ADSL-eligibility however.

Analogue NT units look SIMILAR to the NT-1+2 unit pictured below, though they have the words �Analogue NT� written on them and are missing the data ports on the back.

Below is an NT-1+2 for reference:
www.ceren-networks.com/w...l/nt1plus2_3.jpg

Exicom Hawk

The Exicom Hawk is a radio-based PGS delivering two phone circuits on a 25Khz radio channel. Typically only used in rural areas, and supports data up to 28.8Kbps.
The image below is the remote unit, typically attached to an antenna and installed in the customer's premises. It's function is similar to the NT-1 of an ISDN link.

Image:

www.ceren-networks.com/whirlpool/exicom.jpg

Obsolete Pair Gain Systems

Note: The following have been added purely for historical interest.

GFELLER - Very old Pair Gain System, should be none in existence.

LYNCH – Very old Pair Gain service serving 128 customers maximum from 32 trunk lines. No longer deployed, should be none in service. No other information necessary, as it’s really quite old and outdated. Popular in the 1980s.

FM 1+1 - Even older version of a two channel pair gain system. Should be none in existence, though apparently some still are (in Country Victoria). FM 1+1 conflicts with digital services (like ISDN/A-NT1) in the same bundle, and should have been retired a long time ago.

The primary line on a FM1+1 system will get 28.8K, the secondary line will get 9.6K data speeds.

Loading Coils, Subscriber Line Extenders

These are devices that Telstra typically applies to very long copper runs to minimize echo, attenuation and the effects of EMR. They are incompatible with DSL. If Telstra has had these devices applied to your line, chances are you are too far away for an ADSL line anyway. Your application for ADSL will normally be rejected because of �Line Conditioning Equipment�.

Loading Coil:
www.ceren-networks.com/w.../loadingcoil.jpg

Note: The above picture contains multiple loading coils inside, used for loading multiple cable pairs.

Telstra will not remove line conditioning equipment under most circumstances, though they can be removed to supply an ISDN service. Chances are if you have a long lead-time to installation of an ISDN service - this will be why. Removal of loading coils and installation of an ISDN repeater on the line will generally be required for ISDN services running a long distance from the exchange.

Note: Getting ISDN installed to remove loading coils is a pretty silly idea if your goal is to get ADSL. If your line is loaded - it's likely too far from the exchange for ADSL anyway, so even if you cancel your line, it may well become loaded again, or for ease and speed of reconnecting you - you may simply be allocated another loaded pair.

Can I get ADSL if I am on a RIM/Pair Gain System?

Basically, the current state of play is this: If you’re on a RIM and there is a mini-mux installed, then you’re in luck, provided there is a free port for you, and that your copper run isn’t too long from the RIM. If you’re on a RIM, and there’s no mini-mux, then your only alternative is to try and get copper (see below) or wait for a mini-mux upgrade.

If you’re connected to a new CMUX system, then you should be able to get ADSL provided the ADSL cards are available to slot into the CMUX unit.

If you’re on a small pair gain (2/4 DPGS and similar) setup, then the answer is generally no. You may be able to apply for copper (again, see below), otherwise your choices are pretty limited. In some circumstances, if the small PGS isn’t needed any more (say, if there has been relief copper installed), the copper line(s) used to service the PGS may be reclaimed and used for ADSL, providing that they will meet the requirements for an ADSL-capable line.

Small Pair Gain systems seem to be falling out of favour in recent times, mostly due to the impact they have on customer’s analogue data speeds and availability of ADSL broadband and other technologies, so you may be in luck in the next few years if Telstra opts to remove your small PGS system and install relief copper or a large PGS that supports ADSL.

If you’re on a radio system, you are probably going to be out of luck for quite a long time. It would probably be best to start looking at Satellite.

What are Telstra's Future Plans for upgrading or removing PGS.

Telstra are slowly (and I do mean SLOWLY) upgrading and replacing the worst of the pair gain technologies out there. DRCS systems are being replaced with newer, better systems like RIM. Really awful PGS systems are being recovered and upgraded and internal policies for customers on pair gain are being reviewed. In the last 12 months alone, PGS customers have seen Telstra “cave in” on a number of issues, relating to A-NT1’s, Copper transposition from RIMs, etc.

Remember however, that Pair Gain has its place and will probably exist long into the future.

What can I do about being on a Pair Gain System/RIM.

About Being on a RIM:

This depends on why the RIM was installed in the first place. RIMs can be installed to provide services to an area where there is no copper from the exchange, or they can be installed to supplement existing copper infrastructure that is expected to run out of capacity.

Telstra now offers PGS-connected customers the service of seeking an alternate path that does not go through the PGS equipment. This is commonly known as a Line Transposition Request.

In the case where RIMs are installed to supplement existing network capacity, you will find at the pillar (often marked with a “DA” (Distribution Area) number and an exchange code) that there is copper coming in from the exchange, and copper coming in that is provided by the nearby RIM.

When Telstra receives a transposition request, they will check to see if the equipment in your area is similar to the situation described above, and if so, they can request a technician to swap you from a pair at the pillar connected to the RIM to a pair at the pillar connected to the exchange, providing one is free, undamaged, etc. This kind of switchover is done very quickly by an experienced field technician. The line programming is handled remotely so the switch is mostly transparent for the customer, though their phone may drop out while the transition takes place.

In the case where RIMs are installed to provide initial network capacity, there will be DA pillars installed that will be fed exclusively by the RIM or other pair gain equipment. In this case, transposition will not be available because there is no copper path back to the exchange other than the line provided by the RIM. Unfortunately, a lot of RIM “victims” fall into this group (myself included).

If you’re in this situation, you should keep an eye on the Telstra MiniMux upgrades document available from Telstra Wholesale. If the demand in your area is strong, Telstra will consider your RIM for an upgrade, and if you’re lucky, you will be eventually be able to get ADSL.

Below is the link to the Telstra Wholesale Proposed MiniMux document in Microsoft Excel format.

telstrawholesale.com/pro...band_minimux.xls

If your RIM was installed because there is no existing infrastructure and services were required, then there will be no copper pairs anywhere for you to be connected via. Your choices are fairly limited.

- Wait for MiniMux. Keep an eye on the rollout docs and make sure people in your area register their interest with Telstra.
- See if DoV ISDN or “InFill” ISDN Data is available to you. Some PGS systems (and virtually all RIMs) support ISDN. See the ISDN and DoV FAQ for more information.
- If you want better dial-up and you’re stuck on a NI-RIM panel, you might want to try and get ISDN installed and use the analogue ports on the NT-1 unit for your 56K modem. It’s generally cheaper than 2 separate lines and will provide you with much better dial-up speeds as well as the option to change to ISDN Data/DoV if you ever felt the need.
- Get cable if it’s available to you. Telstra’s pricing has recently changed and may be more attractive now than it was previously with the introduction of the “Unlimited (Subject to AUP)” plans.
- If you’re in a rural area, look at Satellite or ISDN Regional Connect which uses ISDN as the backchannel for 1-way satellite.
- Register your interest with Telstra. This might help you get your area upgraded sooner. www.telstra.com.au/adsl/reg_int.cfm

I’m really, really mad. Can’t I just uh, write my car off into the RIM? That’ll solve the problem, right?

No! Besides being highly illegal, Telstra would want to get services up and running as quickly as possible, which means replacing the infrastructure with the same thing that was already there – usually another RIM.

So, you’ll achieve nothing other than giving yourself a criminal record. The court won’t take lightly to severing the phone services of up to 480 customers – especially when done deliberately.

But, “what if” it happened accidentally? Well, those RIM housings are pretty tough, being designed for the footpath and the hazards associated with that means they’re pretty resilient.

I must emphasize here that if you seek to damage the telephone infrastructure, it is a federal offence and carries very, very severe penalties as you would be damaging national infrastructure. Imagine if you went cutting down power lines because you didn’t like the view – sounds crazy, but it’s the same kind of theory.

Oh, and yes, I have been asked this question.

About being on a Pair Gain system

There are no “hard and fast” rules for getting off a pair gain system. Some people have fought with a lot of effort to get off pair gain and had little result, others submit a complaint once and the pair gain is magically taken care of. Others go via the TIO and eventually receive a satisfactory solution. Look for their stories in other threads in the forums.

All you can really do is apply for a line transposition and hope something comes out of it.

Remember though – in some cases, Telstra may have no real option other than pair gain, such as in rural areas served by systems like RAM/8. There may be no more copper there to actually connect your line to. The same applies to some remote communities using radio trunks to connect to the rest of the network.

If you’re on an Analogue NT-1, you can ask Telstra to remove it, and, provided all other factors of your line are satisfactory (i.e. distance requirements), then you should be able to get ADSL. You will probably be unable to have two lines at your house though, since the A-NT1 cannot be used with ADSL and copper would be in short supply for them to use an A-NT1 in the first place.

More Information

RIM and Pair Gain Action Groups
- Senator Kate Lundy's Pair Gain Victims website

Whirlpool News Articles on RIMs and PGs
- ''Telstra forced to come clean about pair gains'': Labor
- Half-hea�rted victory over pair gains for ACCC
- Telstra to stop rolling out pair gain
- Telstra confesses: 1million customers on pair gain
- Telstra under investigation over pair gains

More Information on RIMs and PGs
- R�IM and Pair Gain FAQ v2.0
- What is this Telstra gizmo?

Updates and/or Corrections

The list of technologies described here is not complete, and will be added to as information becomes available. If you have any corrections or additions, please send a whim to persons mentioned at top of FAQ.