Abstract: Although there already exist many data transfer protocols, they fail to be compatible or compatible well with each other, thus this paper brings forward a creative thinking of making file and file transfer protocol separated, presents a novel structure for adaptive file transfer which supports multiprotocol and three file transfer strategies used in nonlocal network：redundancy check transfer or parallel transfer with file chips is used for large file depending on the file type, transfer based on average quality of service is used for the normal file, and channel multiplexing transfer is used for the small file, besides, transfer based on average quality of service is only used for every file in local network because of the high rate of the file transfer in local network. And on those bases, the algorithm for adaptive file transfer, or the AFTA, is proposed. Experiments indicate that the algorithm can choose a proper protocol according to file’s attributes and other facts, thus it can effectively improve flexibility and efficiency of file transfer, and meanwhile, it ensures the reliability.

Key words: parallel transfer with file chips, channel multiplexing transfer, redundancy check transfer, transfer based on average Quality of Service, adaptive

摘要： 针对目前网络中存在多种数据传输协议，并且各个协议不能或不能很好地兼容其他协议的现状，提出了将文件与文件传输协议进行分离的思想，提出了支持多协议的自适应文件传输的体系结构，提出了针对非局域网的三种文件传输策略：对于大文件依据文件类型采用冗余校验传输或者分片并行传输的策略，对于普通文件采用基于平均服务质量的传输策略，对于小文件采用通道复用的传输策略，而由于局域网的文件传输速率比较高，对于所有文件采用基于平均服务质量的传输策略。在此基础上，提出了自适应文件传输算法AFTA。实验证明其可以依据文件属性等因素，从协议库中选择合适的协议来传输文件，从而有效提高了文件传输的灵活性、高效性，同时保证了可靠性。

关键词: 分片并行传输, 通道复用传输, 冗余校验传输, 基于服务质量（QoS）的传输, 自适应