Duplex house, one telecom connection - questions

What was ordered at Telekom back then? Was it already clear that there would be two independent residential units? In my opinion, only one connection was installed in your garage, so only one twisted pair is connected to the "outside world." You would therefore have to order a second connection from Telekom, and they would have to install a second monopoly TAE in your tenant's premises. The Telekom network extends up to the respective monopoly TAE. Neither you nor o2 have lost anything on that. I have no idea what your electrician was thinking. Or did he also not know that there are separate residential units and also separate telephone connections with possibly different providers to be installed?

Share the internet with your tenant! For calling, you can add a second number with o2 for 4.99 or alternatively get a number from sipgate so they would be independent from you.

Otherwise, if there is Cat6 in the garage, what speaks against Telekom installing a TAE socket next to it and you going into the apartment with the network cable?

Share the internet with your tenant! For calling, you can add a second number for 4.99 at o2 or alternatively book a number at sipgate, so he would be independent of you.

If it doesn't stay within the family, it is always a tricky matter. Unfortunately, they couldn't abolish the liability for disturbances even with the last amendment to the law...

I also think that Telekom has to install a second socket. Where it goes is initially secondary. However, the router (which must be connected to the socket) should be accessible to your tenant. The connection between the two can, however – with the right adapters – definitely be made via an existing network cabling. Of course, the wiring should be of high quality, professionally done, and kept as short as possible.

In my opinion, only one connection was installed in your garage, and therefore only one twin wire is connected to the "outside world."

This is the normal procedure: the ApL only connects the house itself; only the order for the connection triggers the installation of the TAE.

Accordingly, you would have to order a second connection from Telekom, and they must install a second monopoly TAE in your tenant’s premises.

That’s what I’ve been saying all along ;-)

The TAL is only really complete with the TAE. Consequently, the connection provider can only rent the TAL from the line-building connection network operator once it fully exists. This means that the line-building connection network operator is practically always automatically the natural primary supplier of every telephone connection.

Up to the respective monopoly TAE, the network belongs to Telekom. Neither you nor o2 have anything to do with that.

Correct, formal colocation does not really exist at the ApL. In fact, an O2 technician will eventually provide the connection—but only once the monopoly TAE from Telekom is present (which is exactly what O2 asked for).