Sorry, I don’t know why I had replied in Russian.
You can differ WAN connections by the pair of MAC’s used (source and destination are unique for each WAN link). When the new dial-up connection is created you get a call to you ProtocolStatus handler with wan line up event and you can parse and extract the data passed to this call. However, this won’t alllow you to get the exact connection name, you’ll need a user-mode mode agent for this.