Ericsson Ericsson Elevate Technologies Dual Stack MIPv6 (DSMIP) is a MIPv6 extension to support IPv4 mobility for mobile hosts. While route optimization is well defined for IPv6 traffic, this feature is not defined for IPv4. However, Route Optimization has many advantages as reduced delays and lower load for the Home Agent. This document proposes solutions for the different scenarios where IPv4 route optimization is performed.