Cascading failures, the downside of “Eat your own dogfood”

You may have heard that there was a pretty substantial outage in Amazon AWS Cloud services November 25, 2020.  The summary of what happened can be found at: https://aws.amazon.com/message/11201/ and is emblematic of how a simple maintenance action can lead to layer upon layer of unanticipated effects.  Amazon is an amazing company, the AWS service […]

Security Vulnerabilities: Discover, React, Deploy – in 72 Hours

There is a new vulnerability in a common piece of enterprise networking, from the industry leader in the class of device called a “load balancer” that is particularly nasty: https://www.wired.com/story/f5-big-ip-networking-vulnerability/ The vendor is a well known, generally well respected supplier, and reacted quickly and effectively to the exploit, producing a patch quickly and correctly advising […]

Trials and Tribulations with serverless in AWS

So I needed to create a simple database backend with an api for a mobile app. It’s a small, simple database, with several classical join operations. Perfect for MySQL. It has an unusual characteristic: it’s only going to be used once or twice a month for a few days. It’s a problem management system for […]

Getting enough network redundancy at all PSAPs in NG9-1-1

I often hear complaints that in many PSAPs, there isn’t any way to get enough redundancy of network connections to get a reliable ESInet. Often these are rural PSAPs, or larger ones where network diversity wasn’t even considered when siting the facility. I’m here to tell you that I think you CAN get a fair […]

Analysis of CenturyLink Dec 2018 outage: Transport Operator/Supplier Diversity is Critical

The FCC has released its report on the December 27, 2018 outage at CenturyLink that affected 9-1-1 service. The problem was a packet storm in a management network that controlled a major part of CL’s optical network. The packets kept multiplying and congesting the system, and since it was in the management network, it was […]

Where do the NG9-1-1 common nodes go?

One of the bigger architectural decisions when designing an #NG9-1-1 implementation is where the NGCS (central services) go, such as the ECRF, LVF, ESRP and bridge. I’ve been consulting on state-wide NG9-1-1 deployments, and have seen proposals from most of the vendors in the space. I see the following choices: State-specific nodes located in state, […]

Lessons Learned – CenturyLink 911 Outage from August 2018

See my post here to learn more about me and my point of view.  As of this writing, CenturyLink (CL) has recently restored service from a massive outage of their IP network, which affected wireless #E911 service in many areas. We don’t know what happened yet. The FCC is investigating, and we will get a […]