CODECs provide digital instruction to your phone equipment for converting voice into code “packets” that VoIP equipment can process and transmit. Packets break down the information into smaller bits so it transfers quickly and easily. It reconfigures the bits on the other end into the original message. The key quality of a CODEC is whether it compresses voice – compressed voice is a major contributor to poor call quality. Sometimes, CODEC will compress voice to transfer it more easily in the packets.