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Japan Quake


Today’s 8.9 magnitude earthquake in Japan has had surprisingly limited impacts on the structure and routing dynamics of the regional Internet. Of roughly 6,000 Japanese network prefixes in the global routing table, only about 100 were temporarily withdrawn from service — and that number has actually decreased in the hours since the event. Other carriers around the region have reported congestion and drops in traffic due to follow-on effects of the quake, but most websites are up and operational, and the Internet is available to support critical communications.


Those who have been following our blogs on Libya will be familiar with the excellent Google Transparency Report, which summarizes the rate of queries coming from each country over time. Despite terrible fires, floods, and power outages, traffic from Japanese clients just keeps going. It’s quite a remarkable plot.

Why have we not seen more impact on international Internet traffic from this incredibly devastating quake? We don’t know yet, but we’ll keep studying the situation. Compared to the 2006 Taiwan earthquake, which resulted in a larger number of major cable breaks, it appears that the majority of the region’s submarine cables have escaped the worst damage, and diverse capacity remains to carry traffic around the points of damage.
In- and out-bound traffic at the Japan Internet Exchange dropped by some 25 gigabits per second after the quake .. and then climbed back to robust levels by the end of the day.
Traffic at the JPNAP also seems to be down by only about 10% over its historical rates from the last two weeks.




The primary effects seen during the hours after the quake seem to have been related to breaks in 2 segments of Pacnet’s EAC cable system. The plot at right shows prompt increases in unreachable networks in Japan and the Philippines, with follow-on events several hours later in Hong Kong and the Philippines. Various Philippine companies (BellTel, Eastern Telecoms, and Bayan) experienced outages that correlated in time with the initial Japan and subsequent Hong Kong events, suggesting common routing on the affected cable. But again, it’s important to note that these are very small numbers of affected networks, relative to the total Internet presence of these countries.

Since the initial event, the Pacific Crossing system has also gone down. Based on experience from the Taiwan quake, it’s possible that lingering damage to fibers, repeaters, and landing station equipment may continue to generate new problems over the coming days and weeks, even in cable systems that survived the initial event.

Still, it’s clear that Internet connectivity has survived this event better than anyone would have expected. 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, as befits a critical gateway for global connectivity in and out of East Asia. 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.

[Saturday 23:30 UTC] Added JPNAP traffic graph per comments. Thanks!

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  • Tsuneyuki Sakamoto

    I’m living in Tokyo now.
    Almost lifelines had been dead after 2-3 days of the earth quake in Tokyo. The mobile phone had been dead except for the emergency call. And the all real-trafic had stopped. But the internet was available by the both mobile and PC. I had communicated my family and friends, our working team via e-mail and Twitter, facebook and so on.
    Actually, the almost IDC in Japan was alive in the huge accident.
    The below is the status report of the IDC in Japan.
    *Sorry, written by Japanese.

  • A 6.0 magnitude earthquake rocks Tokyo while radioactive emissions from Fakushima reactor increase.
    Japan was gripped in fear when another earthquake shock Tokyo city. The people came out of building as they continued to shake violently. The government officials said that a tsunami threat has been quelled, but changes in sea level near the coastal areas are expected.
    On the other hand, a fire erupted in the Fakushima reactor which saw an increase in the leak of radioactive emissions. The government has given up on the efforts to cool down the nuclear reactors and has ordered the workers to evacuate the area.
    The Japanese government has asked the United States for their assistance in the nuclear crisis.
    For more details Visit

  • My prayers go out to Japan

  • Internet a bien résisté au Japon

    Malgré toutes les catastrophes qui ont frappé le Japon, il y en a une qui ne s’est pas produite : le réseau internet a tenu le coup.
    La société Renesys, qui analyse le fonctionnement d’internet  dans le monde, observe que global…

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