Reliable Multipoint File Transfer Method Using Data Size as a Sequence Indicator

With block transfers, a file is transferred in fixed chunks size made up of a header portion (transmission sequence number and sometimes with a block length) followed by a data portion. With this method, there is no provision for detecting bits lost or scrambled during the transfer. This level of error control is handled by the TCP. As a result, still we have losses caused by noise in lines, transient instability in routing protocols and congestion. Such loss situations are especially existent in Mobile and Wireless Networks. This paper proposes a reliable multipoint file transfer method using data size as a sequence indicator. Sequence numbers are used by the sender and the receiver sides to coordinate and to recover from loss or duplicate chunks and sometime for reordering purpose as well. Our proposed method also allows for more efficient use of the available bandwidth, as we are able to remove the sequence number portion that is currently used within most algorithms like FTP