Here's my take on your networking timeout issue.
Firstly, I'm going to assume you're using a PC with Windows. Here's a few steps to do to see if it's your network timing out or if it's something on your own machine/NIC card failing - or could be a smaller issue such as a bad ethernet cable and result in swapping it out.
First: Do some ping tests to different networks! Start -> Run - > type: cmd -> type: ping 4.2.2.1 /t <- Let this continue for a bit and don't close the command prompt. If you're going to timeout, it'll show it here for a "request timed out"
Here's a example from my network:
Code
[root@firewall.system]/root(1): ping 4.2.2.1
PING 4.2.2.1 (4.2.2.1): 56 data bytes
64 bytes from 4.2.2.1: icmp_seq=0 ttl=59 time=21.722 ms
64 bytes from 4.2.2.1: icmp_seq=1 ttl=59 time=21.200 ms
64 bytes from 4.2.2.1: icmp_seq=2 ttl=59 time=19.920 ms
64 bytes from 4.2.2.1: icmp_seq=3 ttl=59 time=20.138 ms
64 bytes from 4.2.2.1: icmp_seq=4 ttl=59 time=19.662 ms
64 bytes from 4.2.2.1: icmp_seq=5 ttl=59 time=19.571 ms
64 bytes from 4.2.2.1: icmp_seq=6 ttl=59 time=21.982 ms
64 bytes from 4.2.2.1: icmp_seq=7 ttl=59 time=21.606 ms
64 bytes from 4.2.2.1: icmp_seq=8 ttl=59 time=21.474 ms
64 bytes from 4.2.2.1: icmp_seq=9 ttl=59 time=20.195 ms
--- 4.2.2.1 ping statistics ---
10 packets transmitted, 10 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 19.571/20.747/21.982/0.887 ms
As you'll see, no drops.
Secondly: Do the exact same thing as the first step, while keeping the first command prompt open; however, this time you're going to enter in: ping google.com /t - these are 9 times out of 10 going to be completely different networks, or you can just ping d2jsp.org, either is fine!
That's a quick "stress test" to see if your network is actually timing out or if it's something to do with your browser.
If you see actual timeouts and it comes back to as you've been saying, there's a few options to try to ensure it's 100% your network. I'm assuming you don't have much networking knowledge *do pardon me* so it really cancels a few ideas I have in mind, but that's alright.
Get onto another PC on your network, ensure it's a completely different PC/MAC/ETC. Do the exact same steps as before, monitoring the ping responses closely for any network droppings. If nothing happens - you know for sure it's on the PC's end/ethernet cable (unless you're wireless, could be the wireless card?).
If you're still consistently getting drops even on a completely different machine, you'll then need to proceed to this step to pinpoint issues.
Directly connect to the modem by-passing the router completely 100%. You might want to do this on different machines as well to ensure it's a actual drop issue on your ISP's end and not something within your machine.
This is another way of pinpointing the source issue to get down to the bottom of things. At this point after doing all of those steps, here's a few options that I can think of what the problem will be.
First: It's your actual NIC card (motherboards ethernet slot). If it's not happening on another machine, this could be the issue.
Secondly: It's the ethernet cable coming from the router or modem into your machine, try swapping it out with another one and don't use that one.
Third: If you're directly connected to the modem, with a new ethernet cable, tried it out on different machines and persisting to get the same issue - it could possibly be on your ISP's end and not your own - you'll need to give them a call where they can ping nodes/check your modems signals and logs for any drops.
Hopefully some of that helped with limited information I have, if you'd supply some more information/feedback of what the outcome was once you did these steps or similar ones, I'd see what else I could provide.