Thursday, September 8, 2011

Slow Pages? That damn latency, here's one way to make it better...

Your pages are downloading but it takes time for them to show up or they simply feel sluggish. This might not be your computer at all, not even the service you're trying to use, but rather you might be experience domain name resolution (DNS) issues. What that means is that the names you type in your browser or services, do not get properly translated into IP addresses for such services, hence delays or no connections at all will happen. Also having a long latency, or response time, from your ISP's DNS service will certainly slow you down. Recently a friend contacted me with the following question:

"Lately, my LAN is being having latencies of over 2000ms. I was able to trace route to an ISP server. Do you think I should call my ISP and waste my time with them or should I do something else? What do you think?

I am paying for a 10MBit connecting (cable) and the weird thing is that as soon as I load the internet (netflix, youtube, hulu, etc) the connection falls to 1-2MBit and does not stay constant. It was not like that. Could it be a rogue program or maybe a hacker?

Any advise will be welcome. Thanks."

Sounds familiar? Before calling the ISP, there's a couple of things we can check. For me a latency above 100ms will certainly make you feel slower and in the thousands is definitely a sign of some trouble somewhere.

If you're doing a trace and it's getting hung at a server along the route, the question becomes why is it going through there? That might point to a DNS issue or some weird re-routing. Either way, changing your DNS servers from the ISP providers to something like's might give you an improvement or at least, will let you test if this is indeed a DNS issue. This is the web site:

To do that you need to your NIC's configuration, TCP/IP, look for the DNS server section, instead of automatically get it from provider, set to manual and enter the following IP's from OpenDNS as your new DNS servers:

Once set, you can try it with your PC or Mac first, then if it works better for you, change it at the router level. I personally have it mixed between the ISP and OpenDNS. That way if one fails, the other will pick up. Then of course, I love redundancy.

It's important to point out that there might also by the possibility, if you're doing a lot of streaming, that of your ISP putting some sort of "bottleneck" to control your appetite for video, etc.

Can we check first of how do we do it?

Regardless of the cause, we should start by doing some testing. Use the following site:

for download and upload speeds. Then use this to see the line quality:

Figure 1: screen shows and easy to use, yet very detailed GUI which provides a wealth of information about your connection, in an easy to understand way.

Use these tools with both original ISP and OpenDNS configurations to compare once you get the results. If you see an improvement after going to OpenDNS then we know the answer. If not, feel free to let me know and I'll give you some other suggestions. Hope this helps.


We heard back from our friend and good to hear this worked out for him:

"Good news, OpenDNS worked like a charm ... well so far. I tested both the speed and quality and is rated at A with ~30ms pings and 9.75MBit download.

The latencies went down to 59ms average after using OpenDNS.

Thanks for your help and advice."

Final note or recommendation:

One more suggestion. As I mentioned I like redundancy, so even if OpenDNS works great, they're based out of San Francisco. So if anything was to happen to their servers, you get the point. Hence what you can do is that at the router level, use the faster of their two (use the testing tool to determine which one is faster for your connection) and then as secondary, use the DNS IP of your ISP. That way you hit the fastest first, but if it's down, you always can go to your ISP, just in case, even if it's slower. The important thing is that not all the eggs are on the same basket...

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