As the network speed grows, inter-layer coordination becomes more important. This paper shows 3 inter-layer coordination methods; (1) “Comet-TCP”; cooperation of datalink layer and transport layer using hardware, (2) “Transmission Rate Controlled TCP (TRC-TCP)”; cooperation of data-link layer and transport layer using software, and (3) “Dulling Edges of Cooperative Parallel streams (DECP)”; cooperation of transport layer and application layer. We show the experimental results of file transfer at Bandwidth Challenge in SC2003; one and a half round trip from Japan to U.S., 15,000 miles, which has 350 ms RTT and 8.2 Gbps bandwidth. Comet-TCP hardware solution attained max 7.56 Gbps using a pair of 16 IA servers, which is 92% of available bandwidth and DECP software attained max 7.01 Gbps using a pair of 32 IA servers.