There is described an optical terminal for use in a passive optical network. The optical terminal comprises an optical I/O module for sending and receiving optical data packets along an optical fiber, an electrical I/O module for sending and receiving electrical data packets via an electrical connection, a signal converter operatively connected to the optical and electrical I/O modules for converting the data packets between optical and electrical formats, a controller for controlling the operation of the I/O modules and the signal converter. The controller is configured to detect a failure of a primary data path in the optical network, initiate an automatic protection switch to a secondary data path for optical data packets, and generate traffic flow update messages to be sent upstream. Each traffic flow update message contains, as a source address, a MAC address of a client device downstream of the terminal.