This document defines an experimental protocol to reduce the handover latency in Mobile IPv6, which is the time during which a Mobile Node (MN) is unable to send or receive packets due to link switching and IP protocol operations. The protocol enables the MN to send packets immediately after detecting a new subnet link and allows the new Access Router (NAR) to deliver packets to the MN as soon as it detects the MN's attachment. The protocol involves the MN sending a Fast Binding Update (FBU) message to its Previous Access Router (PAR) to establish a tunnel and configure a new Care of Address (CoA). The PAR then responds with a Fast Binding Acknowledgment (FBack) message, which the MN uses to start using the new CoA. The protocol also includes mechanisms for handling packet loss, duplicate address detection, and erroneous movement. The document specifies the protocol operation, message formats, and various options, and provides guidelines for implementing the protocol.This document defines an experimental protocol to reduce the handover latency in Mobile IPv6, which is the time during which a Mobile Node (MN) is unable to send or receive packets due to link switching and IP protocol operations. The protocol enables the MN to send packets immediately after detecting a new subnet link and allows the new Access Router (NAR) to deliver packets to the MN as soon as it detects the MN's attachment. The protocol involves the MN sending a Fast Binding Update (FBU) message to its Previous Access Router (PAR) to establish a tunnel and configure a new Care of Address (CoA). The PAR then responds with a Fast Binding Acknowledgment (FBack) message, which the MN uses to start using the new CoA. The protocol also includes mechanisms for handling packet loss, duplicate address detection, and erroneous movement. The document specifies the protocol operation, message formats, and various options, and provides guidelines for implementing the protocol.