Harald Welte

Who is Harald Welte? Well, that's what this website is all about. Those who know me is that I don't really work for the money, but because a topic is exciting, or if there is some higher goal that can be achieved. I'd rather drop the most lucrative contract and instead work on something exciting and/or revolutionary. From about 1990 onwards, long before the Internet was known to most people and before the web has even been invented, I was involved in data communications and the BBS community, participating in the message-based networks at the time, including Z-Netz, FIDO, TrekNet, CL, MAUS - and subsequently also participating in the UseNet. By about 1994 I was running my own small computer network at home, connected to the outside world via Modems, ISDN and even an analog leased line (38.4kbps) to have always-on connectivity and access to things like e-mail, newsgroups and IRC long before most people had ever heard of the internet. As part of my interest in the world of computer networks, I used to volunteer for KNF , a NGO that enabled internet access to individuals. That's where I got experience with technologies like OSPF, running an Usenet news server (inn), cyrus IMAP server, the smail MTA, Taylor UUCP, dial-up infrastructure, leased-line technology (analog, ISDN, PDH), ISDN PRI/BRI, etc. In the late 1990ies the Internet boom reached Germany, and people with skills in that area were needed to help companies, schools and other organizations to get online and understand how to install, configure and operate DNS, e-mail and web server infrastructure. In 1999 I got involved with the development of netfilter/iptables , the then-experimental new implementation of the Linux packet filter / firewalling code, schedueled for the 2.4.x kernel series. I became one of the netfilter core team members and wes leading it for some time. netfilter/iptables remains the standard linux packet filter until today (2015). As it has been used by literally billions of devices, from consumer-grade DSL and cable modem routers, to Linux based smart phones (Motorola EXZ, WebOS, Android) to more enterprise-grade systems and products. Even though I'm not involved anymore with netfilter/iptables, most of my work has been related with communications technology ad/or its security in some way. I started the OpenEZX project, aiming at providing a Free Software replacement for the overly proprietary Motorola EZX operating system of early smartphones. While the project included a lot of reverse engineering of smart phone hardware and was a lot of fun, it unfortunately was never completed. I became the lead system architect of the OpenMoko project (and second employee of the OpenMoko company). At OpenMoko, we were developing a modern, Linux based smart phone (hardware and software) at a time before the first iPhone or Android were released. This project received my full dedication between 2006 and 2008. After having worked on the electronics and software side of a phone, I wanted to go deeper in to mobile communications and started a free sotftware implementation of the GSM protocol stack on the network side (OpenBSC in 2008) and on the mobile phone side (OsmocomBB in 2010). Under the newly-founded Osmocom umbrella project, I countinued to work on other communications sytems, including for example a receive-only implementation for the TETRA professional mobile radio system. Well, I have to admit a life dedicated to Free Software and such a wide range of technologies doesn't really leave too much spare time for other topics. Before 2005, I still was very fond of photography, particularly the old-fashioned analog/chemical process. I did all the development/prints myself, and it was a lot of fun. These days, I would guess the only non-IT related hobby is my passion for motor bike ridiing. At this point I own the following bikes: