A method of transmitting data, composing: transmitting a plurality of first Real-time Transport Protocol (RTP) data packets to a receiving end over an RTP data link established with the receiving end; receiving a retransmission indication message sent by the receiving end, the retransmission indication message being intended to indicate an RTP data packet to be retransmitted among the plurality of first RTP data packets; encapsulating the RTP data packet to be retransmitted according to the retransmission indication message to obtain a second RTP data packet, wherein the second RTP data packet composes an RTP padding field intended to indicate that the second RTP data packet is a retransmitted RTP data packet, and a type flag of the second RTP data packet is same as a type flag of the first RTP data packet and transmitting the second RTP data packet to the receiving end over the RTP data link.