[cisco-nas] multilink per-user

[Tassos Chatzithomaoglou]

I'm trying to enable/disable "ppp multilink" per-user, which to be honest i don't believe 
it can be done since multilink gets negotiated during the first phase of lcp (before the 
actual authentication, so the per-user config is not known).

I have tried configuring "lcp:interface-config#1=no ppp multilink" in the user's radius 
profile and "ppp multilink" under dialer, or "lcp:interface-config#1=ppp multilink" in the 
user's radius profile and "no ppp multilink" under dialer, but none of them seem to be 
doing what i want, since multilink dialer config always overrides my per-user config.

In the first case if the customer comes with mlp enabled, he ends up with mlp enabled.
In the second case if the customer comes with mlp enabled, he ends up with mlp disabled.

Preauthentication should work here, but i don't have any CLID/DNIS number available.
Any other idea?
Is there a way i can cause lcp renegotiation like in l2tp termination?