class: center, middle # Wireless Community Networks # (Freifunk Berlin) --- # Philipp Borgers * Wireless Community Network activist * Free Software developer * firstname.lastname@example.org * active community member since ~ 5 yeaers --- # Wireless Community Network * community gets together to create a network * network of (wireless) routers * network is common, owned by all participants * all participants cooperate and exhange data freely --- # Motivation * access to information and communication is a human right * share knowledge and learn about technology * it's fun * we climb high towers * break things * play ping/pong --- # International examples * guifi.net (Spain) * NINUX (Italy) * NYC Mesh (U.S, New York) * B4RN (Great Britain) - fiber network --- # Freifunk Berlin * local wireless community network * ~ 750 nodes in Berlin * routing table with ~ 1000 routes * connected to BGP routers in a few data centers --- class: middle, center # [Freifunk Berlin map](https://hopglass.berlin.freifunk.net/) --- # Examples of Freifunk installations * [Rathaus Kreuzberg](https://wiki.freifunk.net/images/f/f9/Rhxb-ostseite.jpg) * [Windrad Tempelhofer Feld](https://wiki.freifunk.net/images/f/f0/Thf-ensemble.jpg) --- # Freifunk Berlin Firmware * Operating system for routers based on OpenWRT * contains: * a wizard/configuration assistant * routing daemon (OLSR) * user interface for management * default configurations * free software hosted on github (freifunk-berlin/firmware) --- # OLSR * layer 3 routing protokol (needs IP address to work) * link state routing (whole graph know to the routing daemon) * metric based on hop count and link quality (dropped packets) * good old software * used in the city wide network --- # BATMAN * layer 2 routing protokol (uses MAC addresses) * creates a big layer 2 network * distance vector routing (stores only a vector of distances and direction) * used in local setups to e.g. enable roaming between APs --- # other routing protocols * BMX (crypto, web of trust) * babel * OLSRv2 (new metrices, e.g. bandwidth) Checkout battlemesh conference in Paris! --- # challenges: local apps * we are looking for (distributed) apps * current apps: * file server * game server * webcams * sensor data (LoRaWAN gateway) --- # challenges: IPv6 prefix delegation in layer 3 networks * gateways have a public IPv6 prefix * gateways actually route and do not NAT * nodes would like to use sub-prefixes of the gateway * how do we distribute prefixes in a layer 3 network? --- # challenges: maintenance * 748 nodes with Freifunk Berlin firmware * no automatic updates * migration to new protocols difficult * users/maintainers are no it experts --- # Freifunk Berlin * meetings every Wednesday @ c-base (Rungestraße) ~ 20:00 * twitter: @freifunk_berlin * matrix channel/chat * mailinglist (email@example.com) * checkout berlin.freifunk.net/contact --- class: center, middle # Questions?