L2TP/IPSEC connection to outside problem

Hello all,

i'm using an L2TP/IPSEC connection to be able to see catch up TV in other country than mine.

i notice that when i'm connected using this VPN client my astaro is cuting the speed by 2 so basically i have normally 4MB and when i'm connected through this VPN i have 2MB ... the astaro is clearly the problem cause if i bypass the astaro by plugin the computer behind the modem everything is OK.

Any idea ?

Cheers