It works only only one occupied port! Once both ports are occupied, the result is disorder and nothing works! Thus, a completely useless product, unless you want to connect only the input cable with only one output cable. But it needs to then actually also no ISDN-Y adapter with two outputs. I have the problem for me then ultimately resolved so that I worried in the short term nor a 20.00 EUR expensive ISDN distributor with Conrad in Stuttgart, with which it now works smoothly. This adapter I'll send back to the seller back because I can not do anything.
