A method for route optimization in a proxy mobile internet protocol-based mobility management protocol having a plurality of mobile nodes each having a mobile node address and a plurality of access routers each having an access router address, said plurality of mobile nodes comprising at least a first mobile node having a local mobility anchor and being anchored at a first access router of said plurality of access routers and a second mobile node anchored at a second access router having a second access router address, where the mobile nodes may belong to different local mobility anchors (LMA1, LMA2), said method comprising the steps of: establishing a first binding cache in said first access router, said first binding cache comprising a mapping of one or more of said plurality of mobile node addresses to one or more of said plurality of access router addresses; populating said first binding cache using an approach by storing at least the mapping of said second mobile node address to said second access router address; updating said mapping of said second mobile node address to a third access router address in said first binding cache in response to a handoff of said second mobile node from said second access router to said third access router, before said handoff, transmitting a packet from said first mobile node via said first access router directly to said second mobile node via said second access router based on said mapping of said second mobile node address in said binding cache in said first access router, and saving in a second cache in the second access router of the second mobile node the first access router address and an indicator indicating that notification has been made to the first access router of association of the second access router with the second mobile node, wherein said approach comprises the steps of querying neighbouring access routers and obtaining the second access router address from the queried neighbouring access routers and comprises, when said handoff occurs, that the second access router, by using its cache, sends a binding update message to the first access router for informing the first access router about said handoff. establishing a first binding cache in said first access router, said first binding cache comprising a mapping of one or more of said plurality of mobile node addresses to one or more of said plurality of access router addresses; populating said first binding cache using an approach by storing at least the mapping of said second mobile node address to said second access router address; updating said mapping of said second mobile node address to a third access router address in said first binding cache in response to a handoff of said second mobile node from said second access router to said third access router, before said handoff, transmitting a packet from said first mobile node via said first access router directly to said second mobile node via said second access router based on said mapping of said second mobile node address in said binding cache in said first access router, and saving in a second cache in the second access router of the second mobile node the first access router address and an indicator indicating that notification has been made to the first access router of association of the second access router with the second mobile node, wherein said approach comprises the steps of querying neighbouring access routers and obtaining the second access router address from the queried neighbouring access routers and comprises, when said handoff occurs, that the second access router, by using its cache, sends a binding update message to the first access router for informing the first access router about said handoff.