At work our IP is
the devil Comcast. When I do a speedtest I get a jump of upwards of 20Mbs and then it slowly goes down to average out at around 10Mbs. The upload speed stays at stead 2-3Mbs. My ping is normal at 30ms.
Now, when I download something from the internet larger than your average webpage the speed bottlenecks. Today, for example, I go download an Azure update for Visual Studio (still downloading) and get 20-200KBs.
I read this article about bottlenecks. It was very vague and didn't really provide troubleshooting steps (what I am looking for) but rather just listed potential problems.
I realize first I must find the problem; I need to isolate it. I have access to practically everything as far as networking goes in my environment, so that's not really an issue. However, I can't just start unplugging and moving cables around, either.
I am very ignorant when it comes to the real technical side of networking (for instance, I can read a Wireshark capture but I cannot interpret what it means).
What I am asking for are some specific troubleshooting steps I can take to isolate the problem. It's a typical small office setup with about 10-15 computers, a hefty fileserver, a few tiny servers for testing, about 3 working switches that go out a Netgear Prosafe Firewall (I was going to provide a link SE won't let me). At least one of the switches is a gigabit switch. (Is my PC going through the gigabit switch? I don't know. Can I find out? I am not sure.) I know I could just start unplugging to figure out which is mine, but like I said, I can't do that. Is there any other way to tell?
Another obvious question, "Does anyone else have the same problem?" Answer: Sometimes. It is really hit or miss. (which makes me think it's not just an issue of who's on the gigabit switch and who's not).
To sum up, are there any troubleshooting steps recommended for my situation?