If this file of 100GB is composed of one or several large files, then the overhead of establishing a tcp connection is relatively small, 500m bandwidth is basically about the same. If it is composed of many small files, this involves what you use the application to transfer, if it is with ftp, then the establishment of tcp connection overhead is very large, the impact on the transmission rate is also very large, 500m obviously can not meet the requirements; there is another way is to write their own program to transfer, to build a tcp connection or a few can be so that the overhead is relatively small. In addition, tcp transmission time there is a maximum segment size (MSS) limit, MSS is the TCP packet each time the maximum data can be transmitted segment. In order to achieve the best transmission performance TCP protocol in the establishment of the connection is usually negotiated between the two sides of the MSS value, the value of the TCP protocol in the implementation of the MTU value is often used instead (need to subtract the size of the header of the IP packet 20Bytes and the header of the TCP data segment of the packet 20Bytes), so if it is based on the transmission of Ethernet, the MSS is often 1460. the two sides of the communication will be determine the maximum MSS value for this connection based on the minimum MSS value provided by both parties.