More and more mobile terminals are embedded with multiple heterogeneous interfaces. Multi-interface mobile terminal can benefit from connecting simultaneously to more than one network. Handling mobility at the transport layer can support seamless handover in the context of heterogeneous networks. In this paper, multihoming and end-to-end features are analyzed to present the proposal of Multihoming-based Cooperative Mobility Management (MCMM). The cooperative mobility management optimizes the handover delay in the heterogeneous access networks. When mobility occurs, update messages are sent over the interface with the smallest delay rather than the interface which triggers the mobility. The MCMM is implemented in C++ under Linux with a test-bed. The experimental results show that the handover delay can be reduced by sending update messages over the interface of the fastest path.