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Hot Topic NBR Focus: GMO
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Dick remembers the day the Southern Cross Cable lost service - and says it will fail again

As Pacific Fibre throws in the towel, the heads of major ISPs worry about threats to NZ's only high capacity connection to the outside world – including human error, slicing anchors, acts of God, island dictatorships and a clocking ticking on mean t

Fri, 03 Aug 2012

In the wake of Pacific Fibre’s funding failure, the heads of major ISPs are worried about threats to the 50% Telecom-owned Southern Cross Cable - New Zealand’s only high capacity connection to the outside world.

Concerns include human error, slicing anchors, acts of God, island dictatorships and a clocking ticking on mean time before failure.

Orcon boss Scott Bartlett told NBR he worried about an earthquake hitting the Southern Cross Cable's landing points in Auckland - an event he said could leave the country without internet for weeks or months.

"Bartlett’s mischievous assertion of the “Southern Cross Network as a flimsy piece of infrastructure” is completely wrong," Southern Cross director of sales and marketing Ross Pfeffer told NBR.

"The Southern Cross Network* comprises two fully diverse cables, using two geographically separate cable stations in each country: NZ, Australia and Hawaii and the US West Coast.

"The network is configured as a self-healing figure “8” and is designed to achieve better than 99.999% availability, equivalent to 5.25 minutes of unavailability annually. Over the last 7 years customer circuit availability has exceeded these design figures.

"To minimise the potential for dual failure in the event of disruptive seismic activity our NZ cable stations have been placed 10.5 kilometres apart at Takapuna and Whenuapai with cable landings on the east and west coasts. [see diagram above right]."

As NBR has previously reported, the figure 8 design allowed the cable to survive an undersea earthquake that took out a shunt on one of its two loops (which also make the 26,000km cable more expensive to maintain).

The day Southern Cross went down
It's a neat argument. But no system is infallible.

And indeed CallPlus chairman Malcolm Dick points out that the Southern Cross Cable suffered a major outage over July 28 and July 29, 2001 (in online comments, Dick as been going on memory, but a Southern Cross incident report obtained by NBR closely aligns his version of events).

LATEST: Southern Cross Cable responds to Dick attack over 20-hour outage

A freak series of events saw both cables in the Southern Cross Network out of action - one down for routine maintenance, the other sliced by a ship's anchor in Sydney Harbour (where a had hit storm and ships were warned to weigh anchor downwind of the cable. One vessel had two anchors down. A crew member only pulled up one. The other dragged through the cable). 

Software used to manage failovers failed.

"This caused a total outage, and Southern Cross staff had to manually route the working segments together, creating a 14-hour outage," Dick says.

Some customers were left without service for 12 hours, others for up to 20 hours.

"Fortunately at that time it was still the dial-up era and there was not much traffic on it, so it attracted little press," Dick told NBR.

The incident also highlighted that while Southern Cross offers fully redundant or "protected" service, not all telco and ISP customers stump up the extra cost required to take advantage of it.

Likelihood of future failure
Dick has also been looking at the statistical likelihood of of a future failure - and he doesn't like what he sees.

He details:

Looking at industry statistics for cable failures:

  • Terrestrial cables have an average failure rate of 1-2 failures per 1000 years per kilometre
  • In various studies I have seen the comment that Submarine cables are about 10 times more reliable that Terrestrial cables
  • Terrestrial cables have a repair time generally of < 48 hours
  • The Southern Cross cable has a repair time (estimated by Southern Cross execs to me some years ago) of three weeks

The maths says we can expect a total outage about once every 15 years," Dick says.

"The outage could happen tomorrow.

"[That's] frightening when you consider our newfound reliance on broadband and the fact that a break can take up to three weeks to repair."

The failure could happen in years, or it could happen tomorrow, Dick says. Either way it will be "catastrophic."  

Dick backs comments from Pacific Fibre cofounder Rod Drury that a second cable operator was need not just for price, but redundancy and security.

Satellites there for fall-back, but would be overwhelmed
Snap Internet CEO Mark Petrie has been one of the few to publicly back Southern Cross on pricing - an area where he has faith the single operator will do the right thing.

But in term's of the possibility of service failure "I second Malcolm Dick's comments" the Snap boss told NBR.

"It is quite a frightening prospect. There would be no option for satellite capacity in my opinion. Maybe for essential services, but residential broadband would come to a very quick halt."

Fiji threat
Dick sees more threats.

"The cable runs into and past Suva in Fiji which is now a dictatorship," he told NBR.

"A couple of years ago, Fiji had a dispute with Tonga resulting in the Fijian Navy destroying the lighthouse put up [on disputed Minerva Reef] for safety."

Tonga erected two new lighthouses to guard the reef.

Dick was sailing through Minerva Reef a couple of weeks ago, and took the photo above of a Tongan naval vessel on patrol.

There are broader tensions.

"The possibility exists that if we annoyed Fiji too much, they have the capability of decommissioning one segment of the cable, leaving New Zealand with a single cable, virtually guaranteeing outages from time to time," Dick says.

Southern Cross has not so far responded to a request for comment on Dick's mean time before failure calculations.

* The cable's full name continues to be The Southern Cross Cable Network; Mr Pfeffer appears to have taken to have switched to calling it the Southern Cross Network to emphasise it has two strands of cable.

By the industry veteran's calculations, we can expect a total failure once every 15 years.

The failure could happen in years, or it could happen tomorrow, Dick says. Either way it will be catastrophic.  

By the industry veteran's calculations, we can expect a total failure once every 15 years.

The failure could happen in years, or it could happen tomorrow, Dick says. Either way it will be catastrophic.  

By the industry veteran's calculations, we can expect a total failure once every 15 years.

The failure could happen in years, or it could happen tomorrow, Dick says. Either way it will be catastrophic.  

 

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Dick remembers the day the Southern Cross Cable lost service - and says it will fail again
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