FileCatalyst’s core transport technology is based on the UDP protocol, which provides a mechanism by which data can be transmitted at precise rates. Files can be transferred over the UDP protocol without being impeded by network impairments such as latency and packet loss, which substantially slow file transfers. However, UDP does not have any means of recovering from lost packets, meaning that in the past there was no way to take advantage of the UDP protocol for reliable transfers over a network with impairments. FileCatalyst adds the reliability and rate control missing from UDP without sacrificing its other desirable properties.
Similar to TCP, the protocol used behind traditional methods of file transfer like FTP, FileCatalyst transfer technology will also break data into blocks. The major difference between FileCatalyst and TCP is that there is no delay while waiting for receipt of a block of data before commencement of the transfer of subsequent blocks of data with FileCatalyst. Transmission of subsequent blocks is initiated immediately, even when previous blocks have not yet been acknowledged. Regardless of network latency, data transmission remains constant with FileCatalyst, enabling transfers to occur at full line speed.
While the subsequent block is being transmitted, the FileCatalyst protocol awaits either acknowledgment of the previous block or a list of missing packets. Missing packets are re-transmitted concurrently with new data being sent for subsequent blocks until the acknowledgment is finally received. This flow of data remains constant, even when there is a large number of missing packets and the process repeats until the entire file is transferred.
To learn more about accelerating file transfers with the FileCatalyst protocol see our white paper Accelerating File Transfers.