Not sure if it would help but when I was at the school we replaced all the switches with Netgear Managed swiches with 1Gig backbone, this made a big difference to the speed but only if as SYNACK says the servers have 1Gig connection.
With the price of switches now it may be worth while move to 1Gig throughout but I would expect the PCs will not take advantage (ie not 1Gig card). However all new PCs would have a 1Gig card.
Finally are the wireless rooms next to each other? Do they have 1 or 2 Access Points? Could these be conflicting and causing problems?
Hope that helps.
Good news is that the times don't change much from during to after school - that suggests that there's not too much load put on the system.
Originally Posted by gman
With just one set of readings it's hard to be certain but the difference between the S->J and the J->J readings is relatively small so I don't think the fibre link is the problem.
You can work out the link speed; you're moving 550 Mbytes of data in (best case) 70 seconds so that's 550/70 Mbytes/s = 7.86 Mbytes per second or (roughly) 80 Mbit/second
That suggests that you've got a 100Mbit/s link both within the junior school and from junior to senior school (your worst case figure is 550Mb in 110 s or about 50Mbit/s - way more than 10Mbit which is the other possibility)
I don't think it's a general connection problem; it wouldn't do any harm to put in a faster link but if you can get 50Mbit/s for your session during a busy time then it suggests that there's "spare" capacity on your link.
Having said that, of course, if the switches are sometimes failing and needing resetting then it may be that when the switch is OK everything works OK (and you get good speeds) but when the switch is crawling you wouldn't get such good speeds.
If you take a machine from the junior school to the senior school (and vice versa), does it work OK? Just wondering if there's something different between the machines?