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Voice over IP | SIP | Linux | IP Networks | Electronics | Microcontrollers | IoT

Technology Solutions

From fundamental concepts to practical examples; for VoIP, SIP, Arduino and more, we’re here help at every step.

Meet the Author

My enthusiasm for electronics started when I was still at school. I taught myself from books, magazines such as Electronics Today International (ETI) and with help from friends. I built a synthesiser in about 1974 and a great friend with a gift for music, especially keyboards, put it through its paces in various bands for several years to follow.

After qualifying in architecture, I somehow got heavily into software development and had a fantastic job writing programs simulating heat flows in buildings to allow engineers to size the building services plant and predict the energy use of the heating and air conditioning systems. After about 10 years I moved into telephony. It allowed me to combine my interests in electronics with my skills as a programmer. I’ve programmed in Fortran, C, C++, Pascal, PHP, Python, bash scripts and a few special purpose languages.

In the final 15 years of my career, I worked mainly with Voice over IP (VoIP), especially based around open source projects like Asterisk and OpenSIPS. Analysing and understanding SIP traces was at the heart of this work. Now retired and pleased to no longer be staring at SIP traces, I’m trying to keep the brain cells active by dumping some of the old knowledge here and building Arduino projects for fun.

Portrait photo of John

“The route headers and record route headers always confused me. This article has cleared up so much mess from my head. Thanks a ton!”

Anirudh

Latest Articles

  • QNAP RTRR Service is disabled after reboot

    If, like me, you use HBS3 to make automatic backups from one QNAP NAS box to another then you may occasionally find they failed and the reason for the failure is that the RTRR service on one of the NAS boxes has disabled itself. I was getting this problem at…

  • Nano 33 IoT: Testing with solar power and BQ25185

    Nano 33 IoT: Testing with solar power and BQ25185

    My objective was to build a battery powered environment monitoring station using an Arduino. It might be an outdoor weather station tracking temperature, pressure and humidity or something to track indoor temperatures. Long battery life was a primary concern. In a previous article, I investigated how to minimise power demand…

  • Nano 33 IoT: Testing battery options and low power mode

    Nano 33 IoT: Testing battery options and low power mode

    In this article, I will describe my attempts to minimise power demand in the Arduino Nano 33 IoT and select the best combination of batteries to use. My objective was to build a battery powered environment monitoring station using an Arduino. This might be an outdoor weather station tracking temperature,…

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