Which cellular providers support internet bonding?

We know that the Telekom and O2 networks are ideally suited. However, we strongly advise against using Vodafone, as there are always problems with the bonding quality and the speed provided. We also know from other manufacturers that there can be Vodafone problems – depending on the mobile phone cell in which you are registered. On the other hand, there is no problem if, for example, two or three Telekom or O2 cards are in the same device.