![]() Figure 4 shows a second-by-second plot of the size of the BGP forwarding from the start of the 29th October (0000UTC) to the end of the 3rd November (2359 UTC) based on scanning the logged BGP updates from a router located in Japan, in AS 4777 and a second router located in Australia, in AS 131072.įigure 4: BGP FIB Size for AS4777 and AS131072 One way to answer this question is to examine the Internet's routing table during this time. It is clear from this Renesys study that a significant number of Internet services in metropolitan New York, across the state of New York, and in neighbouring states were affected, especially between the critical period of landfall and the following twelve hours, as the storm surge took out electricity distribution and supply, and cascading failures of systems came into effect.īut to what extent were these localized events, where networks located in New York around the point of landfall were affected? And to what extent did we observe non-localized effects, where other networks that use facilities in New York for transit services were affected? Can we assess the impact of Sandy's landfall in New York on the global Internet? Renesys has produced an animation of the localized outage consequences for this region, using fine-grained geo-location information to pinpoint the network outages (see Figure 3 below).įigure 3: Renesys animation of localized outages from Superstorm Sandy It's certainly the case that much of the storm's impact was local to the north east of the United States, and New York in particular. How well did the Internet fare in the face of this rather severe climatic event? Did this storm generate outages that were visible across the entire Internet? If you compare these two figures, looking at the storm's landfall and the map of submarine cables and their landing points, then it's evident that Sandy's impact was directly aligned with the landfall points of some 25 submarine cable systems on the New Jersey and New York shores. Satellite image of Sandy's Landfall on October 29 What this image does not show is that because of the anti-clockwise around the storm, there were heavy southerly winds blowing directly onto Long Island, causing a significant storm surge in Long Island and New York City even though the centre of the storm was further south in New Jersey at this time.įigure 2. The centre of the storm made landfall about 5 miles southwest of Atlantic City, New Jersey, as seen in this NOAA GOES013 infrared satellite image (Figure 2). On the evening of the 29th October this year a large storm, post-tropical cyclone Sandy, made landfall near New York at 8pm ET, causing an unprecedented tidal surge, flooding subway tunnels in New York City, and causing widespread power blackouts across much of the north eastern seaboard of the United States. So it is a major connection point in linking the trunk cable transit systems in Europe, America and Asia.įigure 1: Submarine Cable System US landfall, Telegeography One of these critical points of global connectivity is New York, an area that hosts a significant number of submarine cable landing points as it is the major termination point of the North Atlantic submarine system. Can we see this self-healing in today's network? How true is this reputation of network robustness in the face of all kinds of adversity? While the Internet is almost everywhere these days, there are still a small number of locations that host a remarkable amount of Internet connectivity. ![]() ![]() Whether the story of this cold war think tank is true or not, the adoption of a stateless forwarding architecture, coupled with a dynamic routing system, does allow the network to "self-heal" under certain circumstances. The Internet has managed to collect its fair share of mythology, and one of the more persistent myths is that from its genesis in a cold war US think tank in the 1960's the Internet was designed with remarkable ability to "route around damage."
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |