I thought I would share this handy hint.
I've been troubleshooting my DGL-4500 for the past week to see if I have bandwidth issues with my ISP. I've been uncertain as to how much throughput I would get at varying times of the day.
I found a really helpful app (OSX only) that uses SNMP to tell me in real time how much bandwidth is being used. It's called Examinet -
www.examinetapp.com and it just worked with my router.
As it turned out, my ISP did have a line fault and I was able to get it sorted because I could prove slow my service was running at various times of the day.
Anyway, thought you might be interested in this app too given how helpful it has proven to me!