Hundreds of thousands of Kiwi homes might not be able to stream the Rugby World Cup through Spark Sport - at least not smoothly and to a regular television.
The telco's website and app will be the only way to watch every World Cup game live, with various options for those on a fast internet connection to "cast" games to a big-screen TV.
Network provider Chorus says it has the capacity to connect 90,000 premises to Ultrafast Broadband (UFB) fibre between now and the day the Rugby World Cup kicks off on September 20.
That's a problem, because it means even in the best-case scenario, hundreds of thousands of homes will be without UFB fibre - which telco insider-turned-tech-commentator Paul Brislen says is the best way to guarantee a glitch-free World Cup experience.
"Fibre is definitely the answer if you're a rugby fan and want to see all the games on your giant-screen TV without missing a beat," Brislen says.
"There's no issue with contention rates as you have on copper lines."
"Contention" is industry jargon for what happens when older copper lines - which might stream video fine for most of the day - glug up and struggle when everyone piles in at peak times, such as when school's out, prime time (which these days means Netflix time after dinner) or a big sports event that everyone wants to watch at once.
"It's incredibly frustrating having all your neighbours sit down to watch the game at the same time and everyone's connection slows to a crawl as a result," Brislen says.
Fibre also means your connection won't slow if more than one person in your household is using the internet at the same time.
Here is the maths - which, for Spark, just doesn't add up.
According to the Government's latest Broadband Update, for the December quarter, fibre has been laid past 1.43 million premises. (The ultimate goal is to have 1.75m premises within reach of Ultrafast Broadband by 2022.)
But of those 1.43 million, only half - or 714,258 - have got around to phoning their retail ISP (such as Spark, Vodafone or Orcon) and arranged to have fibre connected from the street to their home.
Chorus says it can install fibre at about 3400 homes a week, which means more than 600,000 of those within reach of UFB fibre right now will be fibre-less come World Cup kick-off.
And the network company has limited ability to put its foot down, given the tight labour market and many of its subcontractors already in hot water with the Labour Inspectorate for cutting corners. And even if it didn't have those constraints, the publicly listed Chorus - which won't directly benefit financially from the World Cup - still needs to keep a leash on costs.
The UFB project was awarded to four companies, but Chorus won the lion's share and is responsible for almost all outstanding work now that Enable in Canterbury and NorthPower Fibre in Northland have finished their rollouts and Ultrafast Fibre in the central North Island is coming up the home straight.
There is a separate Rural Broadband Initiative to cover those outside towns and cities.
But on that front, there's potential trouble, too.
Like the UFB, the rural project is proceeding at pace, but was never timelined for the Rugby World Cup.
This month, Crown Infrastructure Partners told MPs that around 40,000 rural households won't have good enough broadband to stream the World Cup.
The message from Chorus chief customer officer Ed Hyde is that rugby fans should book a UFB fibre installation, via their ISP, as soon as possible before those 90,000 spots run out.
It's free for most homes, and fibre plans are comparable in price to copper.
"We know demand is going to be high for fibre installations in the lead-up to the tournament and we want to make sure New Zealand's most ardent supporters don't miss out," Hyde says.
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Chorus is expecting huge data spikes during the Cup.
A spokeswoman for Spark said, "The vast majority of New Zealanders have a broadband connection today that will allow them to stream the Rugby World Cup.
"We have completed a Spark network analysis of how many customers would benefit from moving to fibre in order to watch the Rugby World Cup on Spark Sport. If we assumed that the network demographic is similar for other ISPs, the number of New Zealanders that would need to move to fibre in order to watch the RWC would still be very much within that 90,000 figure."
She adds, "you do need a decent broadband connection to watch streaming services like Spark Sport – but this can be any kind of broadband technology - fibre, copper or wireless broadband.
"The general rule of thumb is that if you can watch streamed content, such as a YouTube video or Lightbox, on the device that you want to watch Spark Sport on during peak hours - 8-9pm in the evening - and are happy with the viewing experience, you should be okay to watch the Rugby World Cup."
If you want to watch Spark Sport on a Smart TV, Spark recommends a minimum download speed of 15 megabits per second (Mbps).
If you want to watch Spark Sport directly on a mobile or tablet, Spark recommends a minimum download speed of 6Mbps.
"You might be able to stream with a slower connection than this, but the quality of the image will be diminished," the spokeswoman says.
That is true - families in areas with poor broadband will still be able to watch the stream. But gathering around a cellphone to watch grainy footage won't have quite the same feel as watching a game on Sky or TVNZ.
You can measure the speed of your broadband connection at Speedtest.net (though remember that if you're on a copper or mobile connection, it could be slower at busy times).
Spark Sport fares well in first test
The brighter news for Spark is that its Spark Sport website and app performed solidly during their first test: the Melbourne Grand Prix - albeit with a relatively modest 9000 subscribers (the $20/month service is free for the first 30 days).
The Melbourne race was simulcast on TVNZ's Duke channel, in case there were problems with Spark Sport, which is still billed as a "beta" or test version.
But Spark says it went sufficiently well that the second race on the calendar - the Bahrain Grand Prix this weekend - will be on Spark Sport only, with no Duke safety net.
Plan B secret for now
The telco says it has a fallback plan if Spark Sport fails during the RWC. At this point, it won't say if it will involve free-to-air partner TVNZ - which is already slated to play the final live, plus several games on delay - but the Herald has been told the plan is to transfer games to Duke within 10 minutes if Spark's app falls over.
The full contingency plan will be revealed next month, Spark says.
Brislen says that if you're in an urban neighbourhood that still lacks UFB fibre, check if your ISP offers fixed wireless (which Spark has been pushing hard and is faster than copper). If you're in a rural or provincial area, a wireless ISP can be a workable alternative. See www.wispa.nz for a list.
If you're a rugby fan, the message from all-comers is get in early. Sort out a fibre connection and, while you're at it, get Chorus or your ISP to check that your home's wi-fi network is up to snuff. Many aren't - and you don't want to be stuck in a monster call centre queue come September.