If they were installing a new exchange, what call-routing method/technology do they use these days?

From my dealings with the carriers, most of the switching is moving to VoIP/SIP.
Some of the hybrid exchanges such as Nortel CS2k are used where ISDN circuits / SS7 connectivity is required.

The majority of fixed line services are disappearing, however, as the NBN takes over. As such, I don't think you'll be seeing any new exchanges provisioned.
Alot of outer-reaching suburbs were connected via RIM's (Remote Integrated Multiplexor) which takes in a fibre line and is like a branch of the local exchange, thereby minimising the amount of copper to deployed. Initially these spelt death if you were looking for ADSL connections, but after some upgrades, they supported the technology.

The introduction of the NBN meant the end of PSTN services Australia wide with Telstra backing out of switching calls from local exchanges as PSTN was non compatible with VOIP.

VOIP calls are SIP switched via each and every ISP for most of them (smaller ISP's you may notice Do NOT offer a phone service) but there are suppliers about who offer just that service (Australian Phone Co is but one of many).
In many cases ISP's are only offering the capacity of ONE phone number per NBN service as their modem/routers only have ONE Phone port on the rear.
IF you need more, then by using a ATA (Analogue Telephone Adapter) plugged into one of the Ethernet ports on the router, you can have as many as you want by using applicably sized ATA's.....about 10 is the current max.
Other ISP's use different routers and in my case its a Netcomm and it has 2 Phone ports so my needs were easily satisfied after I switched ISP's.

The smaller country telephone exchanges yet to be converted to NBN present a problem due to the cable distances involved and the small number of customers. Thus NBN and Telstra have yet to work out exactly HOW they are going to resolve this problem.

As NBN penetration reaches full capacity in city and suburban areas the telephone exchange equipment that myself and many others so carefully maintained will be recovered and scrapped. Also the main cables from the exchange MDF's out to the street pillars (where the NBN boxes are now being installed alongside) will become totally vacant as customers transition across to NBN so they to will be recovered and scrapped thus freeing up considerable duct space for future communication needs.

A quiet revolution is telephone communications.

That is very useful information, it does however give rise to one question.

I live in a small country town, well a village actually, and NBN here is exclusively fixed wireless. The NBN site states that the phone and existing Internet services for fixed wireless customers will not be disconnected by NBN. As a result I am still happy on ADSL2+ and also note that many others on fixed wireless still have their existing landline phones through the copper. In fact given the extent of a recent outage it would seem all of us around here are still on the old PSTN network as far as phones are concerned.

I assume this means that Telstra is switching these PSTN calls out into the VOIP network some how.

The question is - will at some stage I become stranded if I keep sticking my head in the sand in avoiding the fixed wireless NBN.

By way of explanation I live in a hollow that means reception of many signals is extremely poor,this includes mobile phone and even FM radio and even though the NBN tower is not much more than one or two kilometers away it is definitely not line of sight even if I stand on tippy toes on the ridge line of the roof.

Some may be interested to know that I use WiFi calling to receive mobile phone calls over the broadband/local WiFi network which has proven to be extremely handy although I do wish Telstra would add support for text messaging like Optus to the service.

Joe

I was under the impression that all PSTN services will get the chop and that it is all being replaced by various wired connections for populated areas, fixed wireless for fringe areas and satellite for remote areas. This came in after Kevin Rudd and Stephen Conroy threw the beer coaster in the dirt tin and scrapped their original plan to give 98% of customers a fibre connection.

Then again, who knows. NBN management don't even know how to spell KERB correctly when describing one of their network topology offerings so I don't expect anything sane from them with regard to the service they are trying to offer.

I was on a holiday weekend in nearby Lake Conjola two years ago and couldn't help notice the diamond-shaped NBN antennas people were having installed.

Hi Joe,

Telstra are only switching off fixed line network in areas where it is being replaced with NBN. This is in FTTN, FTTP, HFC and FTTC (FTTdp more correctly - distribution point) areas only.

Rural areas on Skymuster (Satellite) and Fixed Wireless will be allowed to keep their existing analogue lines.

Note that you may not be able to keep the ADSL2, however, as the ISPs with the DSLAMs within the exchange may decide to decomission the equipment in favour of providing a single supportable platform, being NBN services.

My family's property has fixed wireless, and we have elected to keep the fixed line phone rather than having it converted to NBN, as there is no mobile communication out there, and we need it for safety given the bad power we have there also.

For fixed wireless, you don't need direct LOS. Our property is 7kn as the crow flies, and there is a big hill in the way. My original plan was to have the NBN equipment at the top of the hill, on Solar/Wind power, and a point-to-point wireless connection back to the house (around 300m).
Off memory, the required signal strenght is -99dBm. This was reduced from -96dBm on the original equipment.

When the tech came to install, he got up on the roof with the antenna, and managed to get the -96dBm that his older test gear required to pass. The connection has been solid with 3/3 signal LEDs on the indoor NTD, with the big hill in the way.



Edit - Re: the SIP/PSTN connectivity within Telstra. The majority of equipment up in the service provider land supports both ISDN and SIP connectivity, or there are devices that allow interoperability between the two platforms. These consist of a digital signal processor that takes in the digital voice stream from the ISDN side, and splits that up into network packets for the VoIP side. Conversely it generates the bit stream from the data packets in the other direction.
In my line of work (Call centre technology) - VoIP is prominent, and only connections to the carriers are ISDN these days. Some of the older PABXs still run TDM technology within them, but given that running everything on a single IP network is more convenient than wiring everything twice (phone & pc) with different cabling, it's being removed.
That said, ISDN is being phased out (Telstra ISDN has reached End-Of-Sale), and the network I operate is 100% VoIP now.

The GSM mobile network runs on ISDN technology from the towers to the PSTN network, however with the advent of 4G, VoLTE and the like, even your mobile calls are ultimately using SIP under the hood.

As I said earlier the powers that be have not really decided exactly how to service the smaller country areas with small exchanges ranging up to possibly about 200 line capacity.

But one line of thought is to leave that existing PSTN system in situ and give all customers who want essentially NBN internet, satellite or fixed wireless NBN feeds and LEAVE the all that existing PSTN stuff as is.

So Joe might well lose his ADSL service and migrate to either fixed wireless or satellite feed and just how its do be done will be entirely determined by NBN on a case by case basis.

As all exiting PSTN systems are digital it is not hard to dangle that off a remote system elsewhere in the country much as most are now done anyway.
Once you have optic fibre in the ground here there and everywhere the sky is the limit as to what you can do with bunches of circuits. The costs and the ease with which it can be provided are minimal.

Instead of having lots of switching centres all over the country you can concentrate that down to a mere handful handling the entire country which in itself reduces the fault liabilities.
BUT conversely when there IS a crash it affects lots more customers.

Copper access will still remain-

From the NBN Fixed Wireles Website
https://www.nbnco.com.au/residential/learn/network-technology/fixed-wireless-explained

==================
Will my existing copper services remain active when I connect to a service over the nbn™ access network?

The existing copper lines and services at your premises will not be altered or changed by connecting to an nbn™ Fixed Wireless (or Sky Muster™ satellite) service.

In Fixed Wireless (or Sky Muster™ satellite) areas, premises will have the choice to keep their existing phone service over the copper network active, or switch over to a VoIP (Voice over Internet Protocol) service on the nbn™ access network through a preferred phone and internet provider – connecting your new phone via the nbn™ supplied equipment. Your provider can assist with your phone and internet services.
==================


Futher more-
https://www.nbnco.com.au/residential/learn/device-compatibility/services-that-will-be-switched-off

The section under "Services that will not be switched off" explictly lists fixed wireless & skymuster serviceed areas will not lose their PSTN connectivity.

As a telecom layman but also one with a "problem-solving" disposition, I was troubled by the perceived issue of integrating/routing legacy voice customers with digital subscribers (let's leave aside the Mobile integration headache for now.) But can now see a pathway for the still popular "fixed line" phone service over the presently ubiquitous home-modem/DSLAM-termination/interface from which, I assume, the voice "line"/address/phone-number is quickly separated, converted to packets (with added category descriptors?) (for separate bit-count toll metering back to the Telcos by third party internetwork-backbone entities?) (assuming their core routers are agile enough to discriminate telco voice only traffic?)

When it was decided to roll out fibre for Internet access, what they should have done at the time was keep copper for the phone network and run fibre along-side it for Internet. This would do two things - provide people with faster Internet and keep the proper telephone network alive so that people can ring 000 in emergencies and still be able to use their phones when the lights go out in a storm, etc.

That makes full logical sense Brad, but then there would have been no business case for the NBN. Other emerging technologies like VDSL would have taken over.
And more to the point, if it makes logical sense, the govt. would never have done it.

But wait a minute, thats what we have now with the FTTN and FTTDP deployments

The problem is the ongoing maintenance of it.
Someone has to pay for it, and with the likes of ISPs offering VoIP solutions, it's not cost-beneficial anymore. I pay around $2k a month at work, for 2000 channels of fully redundant (Sydney/Melbourne) SIP voice circuits. You'd be lucky to get 2x or 3x ISDN 30ch circuits for that much.
Call rates are 3c/minute across Australia, and 6c/min for mobiles.

As such, I could on-sell those as consumer circuits for lets say even $5/mo - a 400% markup. And the call rates would be great. Telstra can't compete with that ($30/mo + high call rates); due to the the exchange maintenance, old analogue equipment or the likes of it that needs to be kept running.

Unfortunately the economies of scale of internet-based telephony price pretty much everything out of the market. This was ultimately inevitable.

and keep the proper telephone network alive

Telstra management gladly turned its back on copper ages ago. There's no way it was going keep the copper network and associated exchanges alive, and the yuppie government doesn't care either.

To think back in the 20th century all that electro-mechanical equipment, batteries, buildings, just to provide voice service.

Now the former monopolies still have those buildings, and now plenty of space inside as electro-mechanical gear (Strowger, Panel-switch, Crossbar) used wide rack frames: Seems the new wonder gear is oriented for the standard 19-inch type racks. Ironic as the 19-inch "Relay-Rack" may predate telecom-tech, originating with the Railways!

When I departed Telstra in 1996 that was due to my area being fully digitised with all the Crossbar gear being scrapped as digital AXE & System 12 taking over my patch with was about 1/3 of the Perth metro area.

Over the next 10 years virtually all the Crossbar and remnants of Step by Step gear all vanished in West Australia and pretty much all of Australia as well due to the digitisation of the network Aust wide.

As that happened most buildings had huge amounts of vacant floor space as even with the explosion in the use of optic fibre equipment it occupied far less space and packed in far more channel capacity than the analogue stuff could only have dreamed of.

The digitisation also meant that the DC power loads were almost constant 24/7 unlike the earlier gear which peaked during the daylight hours and collapsed to almost nothing late at night. That meant more investment in batteries and power gear to float charge them. Even the 3phase standby gen sets had to be upgraded as the AC power requirements also shot up.

The new VOIP network slowly taking over the traditional PSTN setup will still give people reasonable service during AC mains outages as the NBN cabinets have about a 12 hour battery reserve and all the customer has to do to maintain comms during AC mains outages is to invest in a small UPS to keep their Modem/Router up into which their phone is plugged.
There are smaller FTTN NBN boxes that look like an upturned fruit case made out of fibre glass that cater for around 50 customers. I am told that those are Mains powered only with NO battery back up whereas the larger cabinets DO have batteries.


A totally new ball game for all.

And then when you go to the FTTC / FTTdp, your modem inside is powering the fibre unit in the pit.
Sends around 60V DC up the line and powers your port. Which means that you just need to cover your own power, and you're good to go. Relatively straightforward to do with cheap UPS's these days.