A session management function (SMF) sends, to a user plane function (UPF), a session configuration message comprising a packet detection rule (PDR) for a group communication session. The PDR comprises a multicast address mapped to a plurality of wireless devices associated with the group communication session, and a forwarding rule associated with the multicast address. The SMF receives, from the UPF, a data notification indicating multicast data arrival for the plurality of wireless devices associated with the multicast address. The SMF sends, to the UPF, a session modification request indicating downlink tunnel information for transmission of the multicast data by the UPF.