Testing Network Performance

Is there a software tool for checking network performance or capability? Ocassionally I run into a network that browses incredibly slow, prints slow, slow login or something similar.

Of course I check the obvious stuff like settings in network properties, protocols, NIC settings etc. But often find nothing wrong.

I have used packet sniffers but they are quite often cryptic and don’t lend themselves well to evaluating network performance. An ideal tool would test data rates between two devices and perhaps give info on problem areas. Another useful feature would tell me if the workstation was hooked to a hub/switch and capabilities. Like 10/100mbit full/half duplex.

Any suggestions are appreciated.

Brian