International audienceThe C3PO project promotes the development of a new kind of social networks called Spontaneous and Ephemeral Social Networks (SESNs), dedicated to cultural or sports events. SESNs rely on op-portunistic networks formed dynamically by the mobile devices of event attendees. This paper presents the framework developed in the C3PO project to support opportunistic communication in such challenged networks. This framework exploits the different wireless interfaces of the mobile devices (e.g., Bluetooth, Wi-Fi and Wi-Fi Direct) to interconnect them so as to form an opportunistic network