As Telecom's Southern Cross cable goes live, ISP Ihug, which is leasing capacity on the new link, says it won't immediately use it.
Ihug co-founder Tim Wood says since the cable won't be fully functional when it is switched on this week, the ISP is playing it safe.
"These things tend to have some teething problems so we'll wait until the redundancy measures are properly in place," Wood says. "We have our own capacity at the moment so it won't be a problem."
The first phase of the cable is scheduled to go live on Wednesday. The 30,500km link runs from Auckland to Sydney, Suva, Hawaii and the US mainland. The second phase, when the final leg between Hawaii and San Luis Obispo in California goes live, will be completed early in the new year.
Telecom’s international business general manager, Anthony Briscoe, says internet users shouldn't expect to see massive leaps in speed once the cable goes live.
"It doesn't increase the top speed so much as make room for more users at a consistently high speed."
Wood agrees, saying unless users switch to a broadband offering, they won't see a higher speed, rather a more constant level of speed.
"Pretty much all our users are getting 56K at the moment anyway."
Briscoe says the cable will initially go live as a figure-of-six configuration. "The final leg will give us the full figure-of-eight set-up once we’ve dug through 9km of rock at Morro Bay [in California],” says . He says the cable should have an estimated down-time of only 50 minutes in 10 years.
“When you consider that some of the cable is as deep as 1600m, you really don’t want to be hauling it up to fix a break.”
The cable has nine cable stations and 500 repeaters, each costing about $US1 million. The total cost of the cable should be around the $US1 billion mark, making it the largest capital project undertaken by a New Zealand company. Telecom owns 50% of the operating company, with Wireless Optus owning 40% and MCI WorldCom holding the remaining 10%.
The cable itself is a triple-ring configuration — three “self-healing" rings each with two cables. Full capacity should be around the 120Gb/s mark for the majority of the cable, with the Hawaii to California loop reaching 160Gb/s. On November 15 the cable will only reach 25Gb/s but that shouldn’t be a problem for users.
“That’s a maximum speed — we wouldn’t have enough traffic to fill that capacity straight away,” says Telecom spokesman Glen Sowry.
Capacity can be expanded or throttled back using either of the two technologies the cables employ — SDH or WDM. SDH, synchronised digital hierarchy, allows data to be switched between segments of the cable at will. If one segment becomes overloaded, traffic can be diverted to the other half of the network. Users won’t know or notice when this happens — traffic travels between Sydney and California in 70 microseconds.
WDM, wave division multiplexing, allows a number of data streams to be sent down the same fibre strand at different wavelengths, effectively multiplying the capacity of the cable 16-fold, although the technology does allow for up to 80 streams to be carried at once.
The drive for more cables carrying vastly more data is driven by uptake of the internet. Existing links, like the PacRim cable that serves as New Zealand’s main connection to the outside world, would have enough capacity for voice only transmissions until the year 2007. Data traffic has changed all that, according to Briscoe.
“The new FLAG [fibre link around the globe] consortium cable will be a terabyte cable. We will have to look at that kind of size in the future.”