Roger Fajman <RAF@NIHCU.bitnet> (02/28/90)
> To a considerable extent, the absence of a sender-initiated file transfer > mechanism on the Internet was a rather deliberate design decision, not an > accident. Sure, there are some operating system issues, but there are also > ways to get around most of them. The theory was that you should have my > explicit permission before transmitting a large file into my disk space. > This was important in the early days of the ARPANET when "big" computers > had fairly small (by today's standards) disk capacity. But it is perhaps > equally relevant today, when the modal "Internet machine" in many places is > increasing tending to be a fairly "small" workstation, again with limited > disk capacity and, perhaps, the "ability" for its other work to be brought > to a complete halt while receiving a large file. I think it's pretty clear from all the uuencoded mail messages flying around that users want this type of file transfer. PCs and workstations should probably receive unsolicited files at a server, just as with mail. Design decisions made 20 years ago need not limit what is done now -- not all those decisions were right. > The last time I looked, there was no sender-only file transfer mechanism in > ISO OSI FTAM, either, possibly for similar reasons as well as (possibly) > a protocol concern in much of the ISO and CCITT OSI work that has not > significantly influenced Internet or BITNET protocol development: making > sure someone can be found to pay whatever bills the "administrations" feel > like rendering. I'm no X.400 expert, but I've been told that it supports inclusion of arbitrary files in a message. That seems like the right place for it to me. Many PC LAN email systems also support attaching files to a mail message. > Now, ignoring the problem and deciding that the sender should be able to > send off anything to anyone, as in BITNET, is certainly a possible > solution. But it may not be extremely attractive when people have to pay > for lines, packets, and incoming messages and files. And BITNET folks, > before advocating it as a general solution, should perhaps contemplate the > robustness of their systems and networks, in the presence of an attack > based on the unsolicited receipt of a lot of large files. It seems to me that it's no harder to guard against an attack by the unsolicited transmission of large files than it is one via the unsolicited transmission of lots of email messages. If you require some sort of "chit" before being allowed to transmit a file, then the transmission isn't really sender initiated anymore and you can't do nice things like LISTSERV's subscriptions to files.