In this paper, first we discuss some basic knowledge about the random network coding, then we introduce the random linear network coding with some simple models. Secondly, we will consider the coding over packets that randomly arrive to a source node for transmission to a single destination. Then, for broadcasting retransmission, any node of multi-nodes requests the retransmission of information packets. This approach always needs large amounts of broadcasting packets. And, at last, we present a queuing model for a random linear coding scheme that adapts to the amount of traffic at the source node.