Troubleshooting A Slow Website/Internet Connection

Question

When I load my website, there is a significant connection lag. Sometimes, the page will take 20-30 seconds just to connect to the server and sometimes it will never finalize the request, only partially loading the page assets.

Here's the frustrating part about it:

• This problem only occurs on my network - the site loads instantly on other computers.
• I'm able to use the internet normally otherwise, it's just my site. Even online video is no problem.
• I'm fairly certain that it's not a code issue because I have a local copy of the site and it loads instantly, not to mention that it loads instantly on other computers outside of my network.
• I've talked with my hosting company and they can detect no issues with the server.
• I've disabled firewalls and virus protection programs to no effect.
• Resetting the modem and computer does nothing.
• The problem persists across all browsers.

I'm almost positive that it's something to do with our ISP. We moved recently and had no problems with the same setup before we moved across town. Since then, however, they have been working on our network and we had a full 36 hours of downtime 2 weeks ago. However, when I called tech support, they were at a loss at what to do because our internet functions semi-normally other than our site. All diagnostics returned as expected and I get the sense that they're just washing their hands of the matter.

Is there anything that I can do on my end to try to get to the bottom of the problem? Are there specific things I should be asking my ISP to test? I'm really not a network or server expert, so please keep that in mind in your suggestions. I'd be happy to share any relevant details needed about my setup, just ask in the comments and I'll update the question.

Update

• The code on my local server is no different than the production server.
• I tested loading the site simultaneously on my desktop and my iPhone 4 on a 3G network. The iPhone loaded the site in 5 seconds, the desktop in 13.
• I tried other websites that I know are with the same hosting company and they loaded almost instantly.
• Using SpeedTest.net, I tested my connection. My ping rate is 25ms, my download speed is 5.70 Mbps, and my upload rate is 0.87 Mbps.
• The website in question is the one listed in my profile.

Answer 1

Here's a community wiki regarding general network latency troubleshooting techniques. You'll have to pick and choose the methods that best fit your specific situation but it's a good place to start.

Also, since you know it worked fine before you moved and now it doesn't you have already answered the all important of question of "what changed?" between working and non-working status, so start your troubleshooting around things that are related to that (are you using a different connection method, is your new location properly wired, etc.). On the other side of that coin, don't let your (reasonable) assumption that the location move is behind your issues close you to other possibilities - consider it a starting place.

You may need to escalate the issue with your ISP somehow, but I get the sense that you'll have to bring them some specific evidence that you think the issue is on their end. Failing that, getting someone from your organization who is "important" call someone from their organization who is "important" might expedite their willingness to help your troubleshoot.

Sorry, I can't be specific, but general advice for a general problem. Give the community wiki question I linked a through go-over.

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Edit:

Try using http-ping and traceroute from both your desktop to the website and then test the connection going the other way. Compare the packet-loss, response time and routes with those gathered from the same tools from a device that doesn't have the latency issue, such as a machine outside of your network.

Answer 2

You should check other sites as close as possible to your site, so with the same hosting company or on the same server if it's shared hosting or VPS. Do those sites open quickly? Also check a ping response.

If other sites at the host are also slow but other parts of the intrnet fast, then diagnose the network connectivity with (matts)traceroute

If it's just your site at that host then double check it loads quickly from other locations at the same time it's loading slowly for you. Do this on the phone with friend, or better while remotely connected to another machine using VNC or similar.

If it's really just that site that's slow an only for you then check you are actually connecting to the same site. perhaps you altered your host file in development. There is a great plugin for firefox called showip that shows the ip you are actually connected to.

If none of that gets you closer to solution then update your question with the detail of what you did.