[DNA] IPv6 over PPP over GPRS -- once again

["Tero Kauppinen (JO/LMF)" <tero.kauppinen@ericsson.com>]

>  > >  >       LAPTOP <-- PPP --> PHONE <---- GPRS ----> GGSN
>  > >  >
>  > >  > And the same is (obviously) true for UMTS as well...
>  > >
>  > > => The RAs are sent (at least according to the specs) but what you
>  > > might be seeing is that the RA is only sent to the phone and is not
>  > > forwarded to the laptop. So the laptop only sees a PPP connection.
>  >
>  > There is still the question of how the LAPTOP gets the IPv6
>  > prefix without
>  > RA.  Since PPP IPv6CP standards don't specify this, I'm at a loss to
>  > explain it.
> 
> => It doesn't get the prefix in this model.
> It can only get the prefix if PPP is not there. If, for instance,
> a bluetooth PAN profile is used, then it can get the prefix through
> an RA. The phone would be acting like a router in this case.
> 
> Hesham

I thought that there was something wrong with my setup and I came to the conclusion that RAs are indeed sent but I just couldn't see them. However, this was not a correct conclusion either. From the network administrators I learn that RAs never reach the phone because a firewall on their GPRS network side blocks them. I was indeed confused: no RAs and no option in PPP to negotiate a prefix and still the laptop had a global address. 

Took awhile to realize that there is a component missing from the picture and that is RADIUS (RADIUS and IPv6 -- rfc3162). Now the setup starts to make sense: the phone gets an address via a PDP context and it's delivered to the phone by using RADIUS. Does this sound reasonable or am I still in error?

BR,

Tero