|The new EPEG terrestrial cable through Russia and Iran cannot come fast enough for Oman. Last month, three major submarine cables were severed by a ship’s anchor in the shallow waters of the Red Sea, including SEA-ME-WE 3 (SMW3).|
On March 5th, 2012 at 14:00 UTC (10:00 PM China Standard Time), Renesys observed that Cogent (AS174) and China Telecom (AS4134) appear to have dropped their mutual connectivity. Prior to this time, China Telecom regularly announced about 3000 prefixes to Cogent. After depeering, this ASN adjacency no longer exists in the global routing table.
It is a fact of life of global Internet infrastructure that wherever shipping routes and cable routes overlap, submarine cable breaks are going to happen. In just the past two weeks, we’ve seen four major cable breaks: three at the same time in the Red Sea on Feb 17th, and a fourth right offshore near Mombasa, Kenya on Feb 25th.
East Africa has been hit hard by these breaks, but in fact, it’s easy to lose sight of how far Internet connectivity in this region has come in a few short years. It’s stunning to see how much of the Internet infrastructure in Kenya and Uganda is actually still up and running, although congested. East African ISPs have learned a tremendous amount in a short time about designing their networks for resilience and diversity, and that’s evident in the data pertaining to these cable breaks.
The graphic on the right illustrates the impact of the most recent TEAMS cable cut. Our data peg the time of the cut at 09:13 UTC on February 25, 2012, as providers throughout the region see sudden, massive shifts in their international Internet connectivity. Kenya normally has about 550 routed networks, and by this measure, over 60% of the country’s Internet became unreachable at this point. Uganda normally has about 180 routed networks, and experienced a similar degree of impairment. Rwanda and Tanzania do not appear to have been affected by this cable cut, which is not surprising, since TEAMS is a point-to-point cable connecting Kenya to the United Arab Emirates (see Telegeography’s online Submarine Cable Map).
It’s become an annual tradition at Renesys to provide a year-end review of how the Internet providers at the top of our Market Intelligence global AS rankings fared over the previous year. Back in 2008, we chose to look at the 13 providers that spent time in the Top Ten in our IPv4 rankings, hence the name “Baker’s Dozen“. We looked at the same group in 2009 and 2010. This year, we welcome a new member to the group, Telecom Italia Sparkle, or simply Sparkle, and say good-bye to Qwest. We report on a resurgent Cogent and a declining AT&T and Savvis. These latter carriers will probably disappear entirely from next year’s edition to be replaced with the likes of PCCW or perhaps Hurricane Electric. Finally, in this edition, we’ll take our first glimpse at global IPv6 rankings. Complete ranking information about the IPv6 Internet is now part of our Market Intelligence product offering. So let’s dive into the data and highlight some trends and changes we observed in 2011.
Early last month, my blog “Pinning Down Latency” included this prediction:
In the coming weeks we expect to see a dramatic shift in transit as Lebanese providers move away from expensive and high-latency satellite service to IMEWE-based service.
Well, it didn’t take long for this to play out.
We can confirm reports of significant but sporadic Internet outages in the Palestinian Territories today. As many as half of the routed networks of the Palestinian Territories were unreachable (withdrawn from the global routing table), possibly as a result of reported cyber attacks. These outages are the largest we have observed all year for this country, which normally has a fairly stable Internet. Impacted networks are located in both the West Bank and Gaza Strip.
For about 3.5 hours today, almost half of the Internet in Pakistan was down. Renesys observed 46% of the routed networks of Pakistan withdrawn from the global routing table between 19:37 and 23:02 UTC making this the largest Internet outage we have observed in the country in recent years.
Undersea cables are expensive to install. But if you’re an Asian Internet hub trying to connect to other Asian Internet hubs across un-cabled waters, what else can you do?
Well, one alternative we see is Internet Providers heading to California, as many Asian providers opt for Internet paths out of Asia to the west coast of the US, and then back to Asia. These tortuous routes, aptly called hair-pinning (observe their supple shapes), may be cost-effective initially, but generate latency, which can be a problem for some businesses (and their end users).
|Packet latency is a big issue in Internet-based applications (i.e. the stuff in the cloud). In conducting analysis on Internet infrastructure over the years, we have seen many patterns of connectivity. One such pattern that can wreak havoc on latency is “hair-pinning”, a phenomenon where traffic takes an unnecessarily long physical path between two points on the Internet due to suboptimal routing. The increased distance results in increased latency, and the “lag” or “sluggishness” that users experience as a result can hinder latency-sensitive online applications whether they are financial trading applications or MS SharePoint.|
Hurricane Irene knocked out power to millions of homes and businesses as it travelled up the US East Coast this weekend. Even as the winds subsided, torrential rains triggered savage flooding throughout Eastern New York state and Vermont, tearing up roads and exposing the telecommunications infrastructure to further risks. The storm’s impacts were clearly visible in the Internet’s global routing table, as tens of thousands of networks were cut off from the rest of the world.
Here are a couple screenshots from our Internet Health Portal, which we provide to the US Computer Emergency Readiness Team (US-CERT). During an emergency like Hurricane Irene, this tool provides the US-CERT with critical information about the availability of Internet services across America. Working from lists of impacted customers in each state and county, and lists of correlated outage events, we can supply a lot of useful information about the problems being experienced by enterprises in the affected area. That information can be passed along to state and local governments to aid in prioritization of disaster relief.