\input zb-basic \input zb-ioport \iteman{io-port 06060347} \itemau{Seggelmann, Robin; T\"uxen, Michael; Rathgeb, Erwin P.} \itemti{DTLS mobility.} \itemso{Bononi, Luciano (ed.) et al., Distributed computing and networking. 13th international conference, ICDCN 2012, Hong Kong, China, January 3--6, 2012. Proceedings. Berlin: Springer (ISBN 978-3-642-25958-6/pbk). Lecture Notes in Computer Science 7129, 443-457 (2012).} \itemab Summary: Mobile data services have become very popular, but there is still no widely deployed solution supporting handovers between heterogeneous networks. Existing approaches usually require support of the infrastructure, which prevents a widespread use. In this paper, a new solution for mobility based on datagram transport layer security (DTLS) is introduced, which can be implemented in a library as part of an application and does not require any specific support of the operating system or network infrastructure. DTLS can be used by applications directly or by tunneling solutions for providing security and mobility. Additionally, the heartbeat extension for DTLS is presented, which is required for mobility and used to provide the necessary keep-alive functionality as well as to realize a path MTU discovery. \itemrv{~} \itemcc{} \itemut{DTLS; mobility; security} \itemli{doi:10.1007/978-3-642-25959-3\_33} \end