Par Harald Weltebr br br This talk will introduce those sub-projects of Osmocom which are implemented in the Erlang programming language. This includes implementation of the GSMUMTS core network protocols which are used on the roaming interface between mobile operators, such as SCCPTCAP and MAP.br br As those protocols are specified as a combination of ASN.1 based syntaxencoding and SDL-diagrams for state machines, the built-in Erlang support for ASN.1 (asn1casn1rt) as well as the genfsm behaviour for finit estate machines are a natural match.