A wireless device receives, from a base station, a radio resource control message comprising at least one packet data convergence protocol (PDCP) configuration parameter indicating Ethernet header compression for a data radio bearer. The wireless device receives, from the base station and based on the at least one PDCP configuration parameter, mapping information between: a source medium access control (MAC) address and a destination MAC address; and a corresponding header compression index. The wireless device receives a compressed Ethernet packet: compressed based on the mapping information; and comprising the corresponding header compression index.