Forwarding large RTP port ranges to Freeswitch in Docker

tl;dr If you run Freeswitch in Docker and need to forward a RTP port range, you'll run into problems. You can try using the iptable solution explained here. (Exactly the kind of manual setup mess that container deployment is there to solve.)


How do you forward a large number …

Building a Team, Remotely

With engineers in Caracas, Barcelona and Cebu, our tech team becomes more and more distributed and remote. That's exciting, because it opens the door to a wider range of perspectives and ideas. There are also challenges with a remote team, and some of those challenges are well-documented: You can't turn …

Sia: How to invest with Siacoin, Siafund, Obelisk and Time (Part 5)

Sia wants to be the hard drive of the Internet. Underneath the hood, Sia is a cloud storage project, like Dropbox, but it is decentralized and powered by both a blockchain and its own cryptocurrency.

In this blog series I look at the Sia project from various angles. I provide …

Sia's Competitors: S3, Storj, Filecoin, Maidsafe (Part 4)

Sia wants to be the hard drive of the Internet. Underneath the hood, Sia is a cloud storage project, like Dropbox, but it is decentralized and powered by both a blockchain and its own cryptocurrency.

In this blog series I look at the Sia project from various angles. I provide …

Sia: Track record & Operations, a Mid-term Perspective (Part 3)

Sia wants to be the hard drive of the Internet. Underneath the hood, Sia is a cloud storage project, like Dropbox, but it is decentralized and powered by both a blockchain and its own cryptocurrency.

In this blog series I look at the Sia project from various angles. I provide …

Sia: Traveling for the Destination, a Long-term Investment (Part 2)

Sia wants to be the hard drive of the Internet. Underneath the hood, Sia is a cloud storage project, like Dropbox, but it is decentralized and powered by both a blockchain and its own cryptocurrency.

In this blog series I look at the Sia project from various angles. I provide …

Sia: Welcome on a Journey towards Decentralized Cloud Storage (Part 1)

A blog post series about Sia, the decentralized, blockchain-based cloud storage project, its network, technology and coin.

Parts of this series: (1) Intro — (2) Long-term — (3) Mid-term — (4) Competitors — (5) Investing — or Read more about Sia


Ever since a crypto-enthusiastic friend mentioned Sia, the project has held my interest. Sia …

Good intentions, ego and other hazards for operational and strategic impact

Impact is at the core of engageSPARK. Sometimes we're very outspoken about it, at other times the topic more in the background of a busy day, but it's always there. After all, having an impact is the point.

Recently, I've had fruitful discussions with colleagues and friends. I thought it's …

Pitfalls when disabling SSL verification with InsecureSkipVerify in Golang

tl;dr When disabling SSL verification using InsecureSkipVerify, make sure you're not loosing the default config of the default HTTP transport.

Thanks to Zak for troubleshooting this. :)


At engageSPARK we integrated with a bunch of vendors via HTTPS. Recently a vendor forgot to renew their SSL certificate, which prompted connections …

Goroutines at Baker's Day, a deep dive

Recently, I've interviewed a bunch of Gophers, as more and more of the engageSPARK platform is moving over to Go. One thing I noticed is that there is quite a bit of confusion around goroutines, and how they're different/better/faster than OS-threads. That's a bit worrisome, because as a …