Japan comms infrastructure resilience to quake damage revealed

The Japan earthquake has damaged some of the country’s key communication systems, as well as hampering efforts to provide emergency alternatives – but systems engineered to survive disasters have successfully routed around problems, experts report. 

At least four major undersea international communications cables were damaged by the quake. Tim Stronge, head of research at TeleGeography Research, the analysts that tracks the development of global telecommunications infrastructure, said that as of last night the company knew of damage to four submarine cable systems – two going transPacific to the US and two intra-Asia connections.

The transPacific cables are Japan-US Cable Network and Pacific-Crossing 1 (PC-1), while the intraAsian cables that are believed to have been damaged are AOCN-2 and EAC-C2C.

“I don’t know if they are back up yet – I suspect not,” Stronge says.

He said the cause of the damage remained “a bit of a mystery” although acknowledges that it could be due to earthquake damage to the cables themselves, or damage and flooding at the cables’ landing stations on Japan’s eastern shoreline due to the tsunami.

“The industry seems to think that the earthquake caused a landslide on the seabed which damaged the individual portions of cable,” says Stronge. This is what happened in 2006 during an earthquake south of Taiwan, which damaged an intraAsia cable. “This sort of damage is not at all unusual,” he adds. “It is not as widespread disruption, as was seen with the Taiwan earthquake.”

Stronge pointed out that individual cables were often part of a larger system designed for redundancy by routing cables in separate undersea trenches.

“Not all cable systems are built like that,” said Stronge. “Most of the new ones aren’t. Ten years ago people used to build these systems as redundant rings.”

According to Pacific Crossing, the PC-1 tran-Pacific network has four fibre pairs organised in four segments connecting landing stations at Harbour Pointe in Washington, near Seattle; at Grover Beach, California, between San Francisco and Los Angeles; and in Ajigaura, near Tokyo; and Shima, near Osaka and Nagoya.

The company says connectivity on the northern and western arms of the system has been interrupted and that the company is assessing the damage and planning repairs. Service on the southern and eastern arms is unaffected.

EAC-C2C , owned by Pacnet, stretches 36,800 km across Asia, linking Hong Kong, China, Korea, Japan, Taiwan, the Philippines and Singapore. It has a design capacity of 17.92Tbps to 30.72Tbps to and from each of the landing countries.

Stronge says that most of the systems that have been affected come ashore not too far south of Fukushima, with most of the other cables reaching land on a peninsula south of Tokyo. In general, Stronge says, cable companies try to bring cables ashore at different locations in order to avoid them being damaged by the same event.

“It’s a problem when many cables land in one place,” he reports, as happened in Egypt when three cables going onshore at the same place were damaged by one ship dragging its anchor.

The impact of the cable damage “is not as bad as it could have been,” says Stronge.

“Some cable owners have had to scramble to move traffic on to other cables. There may have been an increase in latency but there have been no major blackouts in Asia.”

China Telecom, China's largest fixed-line operator, said on Monday that it had quickly restored services damaged by the quake, which it said had damaged submarine cables landing near the Ibaraki prefecture, slowing access to US websites from China.

James Cowie of Renesys, which analyses globally the state of the Internet, wrote in a 14 March blog posting: “The engineers who built Japan's Internet created a dense web of domestic and international connectivity that is among the richest and most diverse on earth. At this point, it looks like their work may have allowed the Internet to do what it does best: route around catastrophic damage and keep the packets flowing, despite terrible chaos and uncertainty.”

Other forms of communication appear not to have fared so well. Mobile operator NTT DOCOMO said on Tuesday that its network had been disrupted in parts of the Tohoku region, including Miyagi, Fukushima, Iwate, Aomori, Yamagata and Akita prefectures; and parts of the Kanto region, including Tokyo, and Kanagawa, Chiba, Ibaraki, and Tochigi.

Power outages and other damage  has interrupted voice calls and mobile data, with 2470 base stations unavailable in the Tohoku and Kanto regions as of Tuesday (15 March) morning. Voice calls on the FOMA 3G network were disrupted due to heavy demand, especially in Tohuku.

TeleGeography reported on Sunday morning that 11.000 base stations belonging to KDDI, Softbank and DoCoMo were out of commission. NTT East Japan said on Monday that 879,000 telephony lines were out of service, as well as 475,400 fibre-optic lines. The company said it expects the numbers to grow as back-up power supplies become drained.

NTT Communications said on Monday that some of its enterprise IP-VPN and e-VLAN services were partially unavailable in the Tohoku region. NTT Com’s data centre services have not been disrupted.

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