This draft proposes a PMIP-based routing optimization method in
distributed anchor architecture. The anchor of the mobile node is
able to communicate with the anchor of corresponding node directly
using optimized routing. In this draft, there are two modes for the
setup of routing optimization: the direct mode and the relay mode.
The difference between them lies in that whether the routing
optimization is set up directly or under the assistance of a third
anchor. The situation that Communication Node(CN) is a fixed
terminal or a content server is also considered and 3 solutions are
provided correspondingly. The method proposed in this draft can
reduce the delay and save signaling overhead in the current scheme.