How do I correctly set up my network connections?

[Barman58]

The system you are using is of an older form, It is a broadband connection but is worked in the same way as the good old dial up internet. You are therefore already directly connected to the internet, which in your and other cases starts at the Modem.

It is more normal these days to have a routing device in the system - These all need to use a modem but this can be built into the router or a separate "box" - the router is required due to the "norm" being multiple Net enabled devices being in use. The router does what it's name suggests - it routes data from a PC to other devices on the network, (the LAN or Local Area Network), or the internet, (The WAN or Wide Area Network).

None of this is relevant to you as you only have one device which you connect to the net and nothing else. The router, however, also provides other services, the important one, a physical break point that includes a Hardware Firewall that is much more secure than the best Software firewalls and it also provides Network Address Translation which gives you an internal LAN that safer as any of your data that accidentally gets onto the net, even from a single device, will not be accepted by any internet hardware.

This explanation is to explain a little of the reasons that you may wish to add a router although you do not need to.

Also, as your Modem is separate at present I would suggest that if and when T-Online change the system, you ask to keep this arrangement, which will mean that you can obtain a router from whoever you want to, (the ones by the ISP, supplied with a built in modem and even those without are "down to a price" not "up to a quality" items). You seem to be someone who prefers to be in charge of your setup and a better Router will allow this.

There may actually be nothing "Wrong" with your setup at present despite the error messages - T-Online have chosen to retain the old method of connecting to the net, directly rather than using a router in addition to the modem, and windows 7 is making the connection but letting you know that the system is not the optimal,

Windows 7 is designed in the internet age, and expects feedback to come from the modem and the internet itself in certain formats, the Modem is not as advanced and may not give the feedback in the correct form if at all, so windows 7 reports this

 

[Old Owl]

Thank you both, Nigel and Samuria!

So it seems there's not much I can do for as long as the connection depends on that old modem.

I will get a router and I'm already looking around, but the new computer did eat into the budget. Since I know nothing about routers, I'm not sure if I need a particularly good one - the problem is just that I need to find one that can cope with my analog telephone's pulse dialing. As it seems, a Fritzbox 7390 can do that. It's not the latest model, but most likely more up-to-date than my current modem.

And yes, I do want to be in charge of my system - trouble is I usually lack the skills required for it. Doesn't keep me from trying, though...

Old Owl

 

[Barman58]

I would wait until T-Online know what changes, and when, they are making to your system, or their part of it - The internet connection.

When they inform you of the upcoming change you can ask the correct questions, (prompted from here if you wish), about what hardware they will supply, and any costs and what if any you require to purchase yourself.

It may be that what they offer will do whatever you need to do to a level that you are happy with so do not need to spend any money