The invention relates to a technique for forwarding data packets by a gateway device (11). The gateway device ensures an interconnection between the client entities (20, 21) of a local network (4) and a communication network (1), that is to say forwards packets received from a client entity to the communication network by means of a nominal interface and vice versa. The gateway device identifies at least one device (10, 30), termed the relay device, accessible by means of a second interface and able to play a role of relay to forward packets exchanged between a client entity and the communication network. When a packet indicating that a session is initiated is received from a client entity, the gateway device forwards the packets of the session by means of the second interface, when a forwarding selection criterion is satisfied, or by means of the nominal interface in the converse case.