I have an ASA5505, and we are connected to a PPPOE connection through Bellsouth or ATT with a 6Mb business connection. During the day the internet speeds will get extreamly slow - down to 150kb for download speeds. Most of the time I will reboot the ASA and DSL modem and then everything is ok for a little while and then it slows back down again. I've tried talking with Bellsouth/ATT but thats like talking to a brick wall. All they say is unhook the modem and hook it to a PC and then test the connection speed. Which of course works just find and I get the full download speed. So any help is trying to trouble shoot the ASA would be great.
It could be a hardware issue with the ASA. I also have ASDM running but I'm no means an expert in that, I'm more of the command line pig when configuring the ASA.