In infrastructure-based networks devices often move from one attachment point in the network or a sub-network thereof to another attachment point. Communications sessions may be established between Mobile Hosts attached to such nodes. Communications sessions between nodes established using Session Initiation Protocol (SIP), Mobile Internet Protocol with Location Registers (MIP-LR) or Mobile Internet Protocol version 6 (MIPv6) may fail if there is simultaneous mobility of two Mobile Hosts in an ongoing communication session. Stationary binding update proxies and stationary location proxies are introduced into such communications networks in order to provide a solution to the problem of simultaneous mobility of Mobile Hosts. Specific implementation for SIP, MIP-LR and MIPv6 are provided. IN SIP networks, the SIP server for the mobile hosts acts as the stationary binding update proxy and the stationary location proxy. In MIP-LR networks, the Home Location Register (HLR) functions as the stationary binding update proxy and the intercepting is performed by the Foreign Agent or Advertisement Agent. In MIPv6 networks, the home agent of each the first and second mobile host functions as the stationary location proxy and the stationary binding update proxy for each mobile host respectively.