IP QoS Solutions 43 IP QOS SOLUTIONS TCP/IP was standardized in 1981 [RFC793][RFC791]. In 1983, they replaced the Network Control Program ([NCP]) as the principal protocol of the [ARPANET]. Therefore, we can say IP networks preceded ATM networks. In the design of IP, QoS was considered. In the IP header, there was an eight-bit Type of Service (TOS) field.The definition on the TOS field is: Bits 0-2: Bit 3: Bits 4: Bits 5: Bit 6-7: Precedence. 0 = Normal Delay, 1 = Low Delay. 0 = Normal Throughput, 1 = High Throughput. 0 = Normal Reliability, 1 = High Reliability. Reserved for Future Use. 0 1 2 3 4 5 6 7 +-----+-----+-----+-----+-----+-----+-----+-----+ | | | | | | | | PRECEDENCE | D | T | R | 0 | 0 |