[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Large file uploads via PHP - ftp limitations etc...

On Thu, 2006-12-07 at 00:06 -0700, Nate Duehr wrote:
> On Dec 6, 2006, at 2:04 AM, Duncan Robertson wrote:

> >> Blaming the protocol for the network's failings or the training (not)
> >> given to the end-users is silly.
> >>
> >> Nate
> >>
> >
> > If the network has failings I look forward to details of your solution
> > (being that chunk of the internet I don't have any control over). It
> > would be wonderful to use ftp in the way it was intended. Blaming the
> > ftp protocol for the network's failings it would be like blaming the
> > smtp protocol because it's design allows it to be abused by spammers.
> > And yes, I agree, a course in debugging firewall/NAT/proxy issues for
> > the ftp protocol would be handy for everybody before they are allowed
> > use an internet connected computer.
> >
> > Duncan
> I usually point end-users at some kind of GUI client that most mimics  
> the behavior they're used to from their Windows or other machines,  
> which handles doing PASV automatically.  Send 'em a couple of screen  
> shots on how to set it up to connect to the server, and call it a day.

Yes, ftp login banner has something along the lines of "ftp problems? -
try filezilla" as pretty much the first comment, unfortunately the end
users may be "random" (as far as I am concerned) people in "random
locations" (as far as I am concerned) that may need to transfer a file
to one of my end users, and they could be in any country, in any network
situation, with no prior notice to me. Of course most of the time ftp is
Just Fine, but sometimes hairy problems arise.

Another shortcut is the oliver ftp frontend:
for simple ftp stuff, instantly all the messing about with firewall
issues goes away as long as http works, of course then you hit the
limits of the php upload etc, - if this was tweaked to upload in chunks
rather than the entire file at once into RAM and then dump it into ftp
(the php ftp module?) it would be great.

> Tangentially, I have found that most folks (even those who claim not  
> to know much about how to use computers at all) seem to get along  
> fine with WinSCP for using SCP/SFTP, which should work just as well  
> if not a bit slower than an FTP client on the same network.

Yes, thats what I mean, overcome the limitations of the ftp protocol by
not using it. I have just dabbled with winSCP but it seems to solve most
of the problems of ftp, except it needs a dedicated client exe installed
for windows users.. but then to get anything aproaching non-sucking ftp
you need to do this anyway. And yes some place broken for ftp may be
broken for ssh, but the single tcp connection over port 22 ssh uses does
work heaps better in general.
Personally I rarely use ftp, I use rsync over ssh or scp it just seems
for some reason windows users are stuck with this old protocol to move
large files around more by intertia and I end up having to support it as
a lowest common denominator kind of thing.

Also from my research ftp cannot be reliably NATted if any of the
encrypted variants of ftp are
used, meaning you have a choice of telnet level security, or not working
across nat/firewalls.

> But if PASV FTP won't work, the chances of SCP/SFTP working are  
> pretty low.  They're just on a horribly broken network.  Ask them if  
> they're getting what they paid for and turn 'em loose on that admin  
> who's still recovering from the lobotomy... he needs the practice to  
> regain his skills.
And we could even start a legal debate about the SLA and TOS that the
other end have committed to while we are at it, under whatever legal
jurisdiction they happen to be in!

Ok for example lets say I had a user in Laos.. can http reliably but
most other traffic controlled by state firewall. Or a random
netcafe/hotel-that-advertises-internet in (say..) Cambodia.. where
discussions about whether or not the network is broken or how leet their
admins are won't get you far as the place is full of tourists who are
happy if hotmail works, and the staff just turn on "the internet" at the
wall every morning and otherwise have no idea, or concern as long as
google and hotmail pops up. user in that location needs to upload a file
urgently.. of course I can have a great time discussing (in Laos or
Khmer) how much the admin was paid to build the network or the
broken-ness of the network if ftp is failing, but really the job at hand
is just to help the user receive the file(s) ASAP.

Fixing the other end is good if I have time, but I'd also like to have
flexible tools available at my (server) end that can overcome the
brokenness I know I will encounter sooner or later at the other end.


Reply to: