Bill Bennett



VDSL doesn’t get the love it deserves

Everyone knows fibre is the best way to get broadband. It’s reliable and can deliver gigabit speeds. Soon it will be able to go even faster.

After 100 years on top, copper is on the way out for most people. But not for everyone. At least not yet.

There is still life in copper broadband. Scientists and engineers have squeezed every last electron of performance from wire-based data transfer to the point where, with the right conditions, copper can deliver fibre-like speeds.

For the most part, the right conditions means living no more than about 1.5 kilometres from a roadside cabinet or exchange.


VDSL interim until fibre arrives

This is good news because the second phase of New Zealand’s government supported UltraFast Broadband roll-out will not be complete until 2022.

People in areas at the back of the queue will have to make do with copper broadband for now. Fixed wireless broadband is also an option.

Those people in areas not yet scheduled for fibre will wait still longer. Eventually fibre will reach beyond 87 percent of the population, but not soon enough to keep everyone happy.

Chorus, Nokia crank up VDSL speeds

Relief is on the way. Chorus and Nokia are working on the latest version of VDSL2 vectoring which could see copper broadband users get speeds as high as 130 Mbps.

Vectoring uses noise-cancelling technology to remove the crosstalk interference found when many signals share the same copper connection. If that sounds too technical a description, focus on this: Vectoring means higher speed.

You’ll need to be close to a cabinet to get maximum speed. The further you are from the cabinet the slower it gets.

Existing VDSL2 users living next to a cabinet should see speeds of around 80 mbps. One kilometre away from the cabinet the speed drops to around 25 to 30 mbps. By the time you are two kilometres away, the speed is down to around 20 mbps, maybe a fraction lower.

The ratios are likely to be similar when vectoring is applied. So expect around 130 mbps near the cabinet and roughly 30 mbps two kilometres away.

Fibre-like speeds

This isn’t bad. When fibre first went on sale in New Zealand customers were offered 30 mbps plans.

To put the speed in context, Netflix recommends 5 mbps for HD television streaming and 25 mbps for ultra high-definition.

In other words, get ready to enjoy Spark’s streaming coverage of next year’s Rugby World Cup or Premier League football. If that’s not your thing, there are plenty of other streaming TV options.

VDSL fine in practice

Until recently I was getting around 50 to 60 mbps on a non-upgraded VDSL2 copper connection. I live around 700 metres from the nearest cabinet. This gives you some idea of the potential.

Chorus head of Network Technology Martin Sharrock says getting the fastest possible broadband experience to customers is a priority.

He says: “Vectoring has improved average VDSL downstream speeds by over 40 percent and upstream speeds by over 30 percent. This is especially important for rural New Zealand where fibre to the home has not yet been planned.”

Federico Guillén, president of Nokia Fixed Networks, said: “Nokia’s copper solution with vectoring technology compliments Chorus’ fibre roll-out and provides another way to deliver significantly higher speeds that enhance the way customers experience digital content.”

And then there is wireless

As mentioned earlier, fixed wireless broadband is an option for people in areas not served by fibre. Some wireless towers are full, they’re not open to accept more customers. This is the case in my Auckland suburb where fibre is an option.

While fixed wireless broadband can, in theory, deliver speeds faster than VDSL with vectoring to people further away from a cabinet, the speed tends to vary depending on how many others are using the same bandwidth at the same time. It will probably slow down at peak TV viewing times.

If you’re not on fibre, it’s worth investigating both technologies. You can find out if a copper VDSL2 connection is available at your address from the Chorus broadband checker. To get a bigger picture of all your broadband options use InternetNZ’s excellent National Broadband Map.

VDSL broadband missing in action

At Businessdesk Pattrick Smellie reports Chorus chair challenges telcos on slow VDSL uptake.

He writes:

“Some 400,000 internet users in New Zealand are on a slower form of internet connection than is available, with almost no cost involved in changing to the faster version[1], says Patrick Strange, the chairman of telecommunications infrastructure provider, Chorus.

Strange tells Smellie 179,000 customers have VDSL broadband accounts while there are around 400,000 subscribers using ADSL.

More broadband, same dollars

This is odd because VDSL delivers faster broadband than ADSL but the cost is the same. In New Zealand ADSL users might get broadband speeds of up to 24 Mbps on a good day. Most get between 10 and 20 Mbps. While VDSL speeds are in the range of 40 to 60 Mbps.

Typically an ADSL connection is not fast enough to stream high-definition television, while VDSL can handle HD TV and leave plenty of capcity for other users on the same line.

Both ADSL and VDSL deliver broadband over copper connections. In both cases their speed depends on the distance from the exchange or roadside cabinet. This explains why they have a range of speeds.

Fibre broadband still tops

Neither ADSL or VDSL can hold a candle to fibre connections which now go all the way up to 1 Gbps.

Yet they remain important as the fibre network is still under construction. Some urban users will not be connected until 2019. Users in rural areas will have to wait longer. Meanwhile there’s an every growing demand for fast internet services.

Smellie continues:

Asked why retailers, such as Spark and Vodafone, weren’t offering VDSL actively to the ADSL customer base, Strange said: “Good question.”

It is a good question. As you might guess, the answer comes down to money.

Chorus is the monopoly owner of the copper network and acts as a wholesaler. It sells connections to ISPs or retail service providers[2]. They pay the same price whether the connection is VDSL or ASDL.

Pricing VDSL

Most service providers then charge consumers the same price for VSDL and ADSL. There is no extra charge at Vodafone or Orcon.

Spark New Zealand adds $10 to the monthly bill for VDSL customers. The extra charge more than covers the other costs the company faces but it changes the upgrade economics. Spark has an incentive to give broadband customers the best available service.

More than half of all New Zealand households buy unlimited data plans. As a consumer you might pay, say $100 a month for an unlimited VDSL or ADSL broadband plan.

Because a VDSL connection is faster, it will get through more data. This is partly because people with faster broadband connections can do more and download more in the same amount of time.

Need more data

But it is also because some services, especially streaming television, are adaptive. If you have a faster broadband connection, services like Netflix will detect this and download a higher quality picture. That takes up more data.

A service provider buying a copper connection from Chorus also has to pay to get traffic from the node back to their own servers. They also have to buy international capacity. In both cases they have to buy enough bandwidth to keep their customers satisfied.

If a user has faster download speeds thanks to a VDSL connection, then the service provider needs to buy more capacity to service the customer.

A little less margin

When these costs are aggregated over a large number of customers, extra cost of carrying VDSL traffic compared with ADSL traffic is tiny, but service provider margins are razor-thin.

In most cases service providers buy capacity in advance. They have to anticipate demand, big jumps in demand can add to their costs. If, say, all their customers wanted to switch from ADSL to VSDL overnight, they would face a big increase.

There’s also a small management overhead switching customers from one service to another. And for those service providers who supply routers and modems to customers there is the cost of hardware upgrades.

For all these reasons many service providers are not in a hurry to upgrade copper connections from ADSL to VDSL.

As a broadband user, you should make a point of asking for an upgrade. It may not cost you anything, unless you’re a Spark customer.

  1. In most cases you will need a new home router or modem. Expect to pay a one-off $100 or so.  ↩
  2. Chorus prefers to use the term retail service provider or RSP. This makes sense as these days many service providers sell more than just internet.  ↩

Long-reach VDSL2 has potential for rural NZ

Communications Day reports BT is testing a long-reach version of VDSL2 in rural areas. The story first appeared at ISP Review.

Long-reach VDSL2 could be ideal for those parts of New Zealand falling between the urban UFB fibre-based network and the fixed wireless broadband delivered by Rural Broadband Initiative towers.

At the moment the government is looking at tenders from companies aiming to reach some of these areas through the second phase of its UFB project.

Extending copper into the wop wops with VDSL2

VDSL2 already extends the broadband capacity of New Zealand’s copper phone networks, especially in places where fibre is not yet available. Typically customers with VDSL connections enjoy fibre-like speeds over copper.

The problem with conventional VDSL is that its performance drops off over distance. If you live near an exchange or a fibre-fed roadside cabinet you might see speeds in excess of 40Mbps. By the time you are a kilometre from the connection point that speed might drop to half the maximum.

The long-reach VDSL2 on trial in the UK gets around that. Communications Day quotes BT saying it “should deliver more than twice the data speeds of existing broadband networks over a distance of up to 2km.”

“LR-VDSL exploits existing features currently defined in ITU-T Recommendations G.993.2 and G.993.5 to enable fibre-to-the-cabinet VDSL2 lines with a D-side length in excess of 1.25km (0.5mm diameter copper) to be uplifted to give a higher downstream rate,”

long reach vdsl2 performance


BT say proof of concept trial in April showed that a copper line delivering 9Mbps could be “uplifted” to 24Mbps with the technology.

It seems VDSL2 isn’t suitable for all copper lines, but BT says the technology in the long-reach version could manage 40Mbps down and 10Mbps up over a distance of up to 2 kilometres.

Chorus’ cabinet network already extends to most settlements throughout New Zealand, even small places. If the reach of each cabinet can be extended using long-reach VSDL2 there will be few communities not served by decent broadband services delivered over copper.

Telecom VDSL, small town users biggest winners

Telecom has begun selling VDSL in New Zealand.

The company says the service will reach about two in three homes delivering a substantially faster internet experience than ADSL.

VDSL or very-high speed digital subscriber line is a technology that uses the older copper telephone network to deliver decent broadband speeds to homes that can’t yet get fibre.

These speeds are fast enough for customers to be able to use high-definition streaming television services as well as voice and internet access on a single line.

Prices are higher than ADSL, Telecom charges $10 more for VDLS than for comparable ADSL plans. In addition there are installation charges $99 for home users willing to commit to a year’s contract and $299 for those who don’t. A 500GB plan is $129. Businesses will pay the same as for existing ADSL plans but there’s a $199 installation fee.

Distance from exchange or cabinet is crucial

VDSL speeds depend on how far a building is from an exchange or roadside cabinet. After the first kilometre or so, performance drops.

In most cases they are comparable with low-end fibre speeds on the UFB network. And for most users represent a big jump from ADSL speeds.

In my case I live around 600m from a cabinet and testing shows I should be able to see 40Mbps down and 10Mbps up. With ADSL I typically get 12 to 14Mbps down and less than 1Mbps up.

In a media statement Telecom Retail CEO Chris Quin said VDSL gives users a taste of fibre ahead of the nationwide UFB roll-out. That’s true, low-end fibre speeds are similar to VDSL, but the UFB network will be more reliable and have lower latency. The biggest winners will be users in small towns that are not scheduled to join the UFB network but are already on the Chorus cabinet network.