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A SIP library is born
Inspired by Andrijan Möcker’s “Überallklingel” (Everywhere Bell), I decided to create my own. However, I wanted to use it with a motion sensor and therefore to be able to turn it off and on again, when necessary. I also felt that using Asterisk was overkill and it could be done quickly and much easier with…
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Software CRC Computation
[simple_series title=”CRC Tutorial”] /* Created with crc4tab[i] = crc(i); */ char crc4tab = { /* 0:*/ 0, 3, 6, 5, /* 4:*/12, 15, 10, 9, /* 8:*/11, 8, 13, 14, /*12:*/ 7, 4, 1, 2}; int nibble, sum = 0; /* getNextNibble() also needs to return a placeholder for the CRC when sending */ while…
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Modern ejabberd configuration
ejabberd is one of the most widely used XMPP servers. It is easy to get it running for text-based messaging with a few configuration changes. However, to obtain a smoothly running modern feature set is harder. The configuration documentation is detailed, but even for a seasoned systems administrator or XMPP guru, a lot of questions…
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The FTX crypto exchange and its spider web
Yesterday, the U.S. Securities and Exchange Commission (SEC) released its indictment against Sam Bankman-Fried. It details the financial entanglements of FTX, Alameda Research and more than a hundred other companies and individuals. We have tried to disentangle these allegations somewhat for you.
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DNSSEC for .ch domains
This year, all owners of .ch domains need to switch from the DNS registry SWITCH to a new registrar. Getting an overview over these registrars is hard. Thankfully, Marc Wäckerlin has started the road to transparency with a price comparison of Swiss .ch domain registrars. Here, I extend his results with a survey of DNSSEC…
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VirtualBox DHCP nameserver for NAT network
VirtualBox is a great environment for testing networking tools such as opDNS. However, I did not get the VirtualBox DHCP server for NAT network to provide nameserver information, even though the client asks for it. Here’s a simple solution to this problem.