@Wobbo You seem to be misunderstanding what the router is doing. It's a way to make sure the internet connection works. The communication to these URLs is called a ping. It's basically the same as you walking down the main street in a town and saying hello to the shopkeepers on the way through.

It pings these particular URLs as they are using datacentres around the world, have a high profile and most likely to be available, so best for testing. 

If you went into town, at a random time of day, to say hello to someone in a local shop that only worked 9-5 and only had one store, more often than not, you're less likely to get a hello back compared to saying hello to a chain of stores open 24/7 through every town as it's less likely to be open when you go. 

@richpriest 

Great way to explain! But it is not necessary for them to do this every 5 minutes, is it? When a group starts knocking on the door every 5 minutes I get quite pissed off. I do want to know who they are and indicate that they have to leave and not come again. In the Netherlands you can place a sticker on the door in which you indicate who is allowed to knock or post at the door. For example, NO no unaddressed advertising material and NO no door-to-door papers.

TP-Link has decided without permission that these companies should knock on the door. So, is this allowed and how do I change it?

Wobbo wrote

@richpriest 

Great way to explain! But it is not necessary for them to do this every 5 minutes, is it? When a group starts knocking on the door every 5 minutes I get quite pissed off. I do want to know who they are and indicate that they have to leave and not come again. In the Netherlands you can place a sticker on the door in which you indicate who is allowed to knock or post at the door. For example, NO no unaddressed advertising material and NO no door-to-door papers.

TP-Link has decided without permission that these companies should knock on the door. So, is this allowed and how do I change it?

@Wobbo 

>> Great way to explain! But it is not necessary for them to do this every 5 minutes, is it?

How long do you want to spend troubleshooting before your router tells you that the ISP's link is down? 30 seconds? 5 minutes? 30 minutes of fumbling around with cables, rebooting your devices? it could, in theory, ping every second, but that isn't practical in many ways. If it left the checks for every hour, you'd be upset that you've wasted so long trying to fix your network when it's your ISP's link at fault.

>>  When a group starts knocking on the door every 5 minutes I get quite pissed off. I do want to know who they are and indicate that they have to leave and not come again. In the Netherlands you can place a sticker on the door in which you indicate who is allowed to knock or post at the door. For example, NO no unaddressed advertising material and NO no door-to-door papers.

Again, you are misunderstanding, it's you doing the knocking/saying hello, not the shops/companies. You need to take your 'they're out to get me' hat off and think about what is being performed here, not everything is nefarious. 

These URLs have likely been specifically chosen as: 

a) They are available worldwide*, so can be integrated to all firmware for every region, cutting development time and costs 

*(I'm not getting into the "Great Firewall of China" argument here).

b) They have a huge amount of resources behind them to keep them available 24/7/365 with super-fast response times. There is no point testing for something that isn't likely to be there (see my previous response's scenario regarding shops). 

c) Testing a multitude of URLs, each hosted by multiple providers on multiple networks in multiple places is better than testing just one or two URLs. Especially if the URL owned by TP-Link would require such resources as point b) to maintain. You're already complaining about it doing any checks at all, so I'm guessing you'd be pretty upset with it appearing to 'calling home' to TP-Link every few minutes instead. 

@richpriest 

To add to this: if I am not mistaken, it is not even web site pings but DNS queries.

@richpriest 

Do all browsers do this? I generally know who I'm at the door of before knocking on the window. Strange, I don't know but TP link does.