Nokia Siemens Networks Muenster Univ. of Applied Sciences Transport layer mobility management is presented in addition to Mobile IP for providing seamless mobility in the Internet. By use of SCTP (Stream Control Transmission Protocol) and some of its currently proposed extensions a seamless handover can be fully accomplished in the mobile client without any provisions in the network, only assisted by functions embedded in Mobile SCTP enabled servers. Client mobility management based on Mobile SCTP seems not to require any new protocol development. It is a particular application of SCTP eventually solving the requirements of transport layer mobility in the Internet.