Hi Oxiel!
I've added the Alcatel-Auth-Group attribute to dictionary.alcatel like these: ATTRIBUTE Alcatel-Auth-Group 134 integer and modified users file like these: Tunnel-Type += 13, Tunnel-Medium-Type += 6, Alcatel-Auth-Group += 3
I'm afraid you added it in the wrong place, dictionary.alcatel does not contain the VSAs for Omniswitches (Alcatel-Lucent has multiple dictionaries for different products, dictionary.alcatel appears to be for a BRAS, not for an enterprise switch). The dictionary you're looking for is dictionary.xylan; the easiest way is to use Xylan-Auth-Group for sending your VLAN (The name isn't really that important, what is important is that the number for the attribute is correct (1 in this case) and that it is defined with the proper vendor number (800 for Omniswitches)).
Gtnx Marcel (The disclaimer again, just to prevent trouble)This mail does not represent Alcatel-Lucent in any way. Everything I have written in this mail is either my opinion or information I interpreted from publically available documents (I found the manuals through Google on a server that, judging from its name, is open for public access). I don't work in a department that has anything to do with Omniswitches and have not used them myself. Because of that, this information may be inaccurate or even plain wrong, Alcatel-Lucent is not responsible for the accuracy of this information. I'm just trying to be helpful here based on what I know.