This is a CRC simulative system that simulates data transmissions from sender to receiver. A certain number of messaging frames (packets) randomly produced bit by bit, is considered to be transferred with a probability of (0.5 * packet_length) to be altered during transmission. The algorithm uses the CRC technic to check if the receiver's packet is the same to the sender's one. There is a small probability of considering an altered packet as the same as the original.