RFC 1068 (rfc1068) - Page 2 of 27
Background File Transfer Program (BFTP)
Alternative Format: Original Text Document
RFC 1068 August 1988
Background file transfer has a number of potential advantages for a
user:
o No Waiting
The user can request a large transfer and ignore it until a
notification message arrives through some common channel (e.g.,
electronic mail).
o End-to-end Reliability
The FTC daemon can try a transfer repeatedly until it either
succeeds or fails permanently. This provides reliable end-to-
end delivery of a file, in spite of the source or destination
host being down or poor Internet connectivity during some time
period.
o Multiple File Delivery
In order for background file transfer to be accepted in the
Internet, it may have to include some "value-added" services.
One such service would be an implementation of a multiple file
transfer capability for all hosts. Such a facility is suggested
in RFC-959 (see the description of "NLST") and implemented in
some User-FTP programs.
o Deferred Delivery
The user may wish to defer a large transfer until an off-peak
period. This may become important when parts of the Internet
adopt accounting and traffic-based cost-recovery mechanisms.
There is a serious human-engineering problem with background file
transfer: if the user makes a mistake in entering parameters, this
mistake may not become apparent until much later. This can be the
cause of severe user frustration. To avoid this problem, the user
interface program ought to verify the correctness of as many of the
parameters as possible when they are entered. Of course, such
foreground verification of parameters is not possible if the remote
host to which the parameters apply is currently unreachable.
To explore the usefulness of background file transfer in the present
Internet, we have implemented a file-mover service which we call the
Background File Transfer Program or BFTP.
Section 2 describes BFTP and Section 3 presents our experience and
conclusions. The appendices contain detailed information about the
DeSchon & Braden