i have an PIX 515e with 8.0 version and in the other side a 2811 router, the site to site vpn between these two device is established, but i want some remote client can connect to pix ,
so is this possibe two implement site to site and remote access vpn on one pix interface (outside) ??
Yes, this is perfectly possible. Please see attached configuration example. Note it is for pix v7.x but it should work fine for 8.x