Gustav: 3 days later

| 1 Comment

All reports from Louisiana indicate that power outages as a result of Gustav are extensive and ongoing, with over a million customers still without service and with potentially very long waits ahead of them. The extent of the power outages can be seen in regularly updated maps provided by the state. (A comprehensive list of utilities by region does not seem to be available.) We've even heard from state officials that the power problems are worse now than they were after Katrina. So it would be natural to assume that the ISPs in the state were similarly impacted, but that is not the case. Internet connectivity is alive and well in Louisiana and the other Gulf states, with all major providers operational, via either conventional or backup power. End users should have connectivity once power is restored to their homes. We'll review the past three days from an Internet perspective in what follows.

Since Louisiana was impacted the most, we will focus entirely on the 1563 network prefixes that geo-locate to this state. The following graph shows prefix outage counts from 10:00 UTC on Monday, September 1st — the hurricane made landfall at 14:30 UTC — until 10:00 UTC on Thursday, September 4th. You can see an initial gradual increase in outages and a few sharp peaks along the way, followed by a return to normalcy on Wednesday.

The peaks in the graph largely correspond to Bell South outages in the Baton Rouge area, although the highest peak has a significant contribution from networks around Shreveport, in the far northwest corner of the state. The prevalence of Bell South outages is not surprising, given that they had the most to lose. In particular, 36% of all prefixes that geo-locate to Louisiana are originated by Bell South. The next largest providers by prefix count are CenturyTel at 7% and Cox Communications at 6%.

To get an idea of the cumulative impact on the state, we plotted all outages observed over these three days onto a single map, regardless of when they occurred during the time period. Not surprisingly, both the network and power outages traced out paths similar to the path of the storm. What is surprising is that while the networks quickly came back, the power grid did not. This speaks to thorough disaster planning on the part of the local ISPs and we congratulate them on their resiliency. Finally, for those of you with Google Earth installed, you can watch an animation of these outages over time here.

Using the time scrollbar in the upper center, you can see the outages progress over time and then gradually dissipate.

We'll leave Gustav for now. With Hanna and Ike headed toward the U.S., there should be plenty to blog about next week.

1 Comment

Thanks for the good and detailed analysis.

My understanding is that part of the power problem is that New Orleans and Baton Rouge had enough transmission lines downed that they formed a "power island" per this Entergy press release with New Orleans disconnected from the rest of the Eastern power grid.

The map you link to above has outage reporting detail as best I've been able to find them. There's also grid operations maps at a regional level managed by a set of ISOs ("Independent System Operators") which manage power flows within regions. I'll overlay those maps as I sort them out; they tell you more about grid as a whole than individual detail points.

About the Renesys Blog

Our weblog is written by a variety of Renesys employees. They run the gamut from senior execs and engineers to sales guys. Anyone who has something to say that could be informative or of interest to our customers and visitors, says it here.

About this Entry

This page contains a single entry by Earl Zmijewski published on September 4, 2008 2:09 PM.

ISPs Learn from Katrina, Survive Gustav was the previous entry in this blog.

Ike Hammers Texas Internet is the next entry in this blog.

Find recent content on the main index or look in the archives to find all content.

Pages