on uploading or attaching files > 1 MB

[Tom Kendall]

As more and more teachers at my school attempt to email large files,
i.e. photos, ppts, I'm hearing more and more come back to me
complaining that it either takes too long or there is a returned
server error message (in the case of gmail, one of their Oops
messages.) The school is on the Schools Broadband Network, dsl,
SmartTelecom. Might someone be able to comment as to whether or not
there are issues when uploading and/or attaching files approximately 1
MB or larger?

Regards,
Tom

[Gavin McCullagh]

Hi,

In principal there shouldn't be. Even on a very slow connection, you
should be able to _eventually_ upload moreorless any size of file. 1MB is
really not a large file in this day and age.

That said, if there is a lot of loss on a link (not unheard of on poor
quality DSL lines), it could be very slow and the connection could even
break down. Obviously, the larger the file, the more likely that could
happen. Even when all is working well, your upload is obviously slower
than your download.

HEAnet keep "smokeping" graphs of each school's link. This means they send
a ping packet to your cisco router frequently, to monitor the round trip
time, spotting unusual delay (usually caused by congestion) and loss (which
can be caused by extreme congestion or a dodgy link). If you can work out
which graph set is yours, you might be able to see if your link is
suffering from loss.

http://smokeping.schools.edu.ie/cgi-bin/smokeping.cgi?target=World.kp.kp-ar1.s5821-cr

If you need to send really large files (eg >5MB), most mail servers will
enforce a maximum size for a single email. The simplest solution to that
is something like yousendit, which allows you to upload a file to them and
send someone the link.

http://www.yousendit.com/

but if you can't reliably upload the file over your link, that won't help.

Gavin

[Stephen McFarlane]

No expert here but don't download and upload speeds differ depending the
account you have with your provider? For example broadband may download at
1MB but may only upload at 128k (or 256k). I know most ISP cap uploads
around 512k unless the user has specifically requested a better upload
speed.

You could just get the root of the problem by analyzing the reason why
people need files larger than 1MB particularly if they are for web or screen
classroom use. Converting to PDF will automatically reduce file size as well
as converting to JPEG for the PPT files.

Steve

[Ban Ryan]

Hi Tom
Gmail supports 20MB so 1MB shouldn't be a problem

Too high latency (long pings) as per sat. based networks can cause problems.
You could also   your upload speed at

http://www.irishisptest.com/login.php?meh=0

Ban

[Tom Kendall]

Thank you Gavin, Steven and Ban for the feedback. Gavin, I'd say you
are right in that the problem is a poor quality dsl line. I'm not sure
what next steps are but I will query the NCTE helpdesk.

Regards,
Tom

2008/9/22 Gavin McCullagh <gmccu...@gmail.com>: