I have had one heck of a time trying to get QT Streaming to work over 
IP-NAT.  After the gracious help from someone in the netbsd 
newsgroup, this got me on the right track:

/etc/ipnat.conf

map ppp0 10.0.0.0/24 -> 0.0.0.0/32 portmap tcp/udp 5000:20000
map ppp0 10.0.0.0/24 -> 0.0.0.0/32
rdr ppp0 0/0 port 554 -> 10.0.0.2 port 554 tcp
rdr ppp0 0/0 port 6970 -> 10.0.0.2 port 6970 udp
rdr ppp0 0/0 port 6971 -> 10.0.0.2 port 6971 udp
rdr ppp0 0/0 port 6972 -> 10.0.0.2 port 6972 udp
rdr ppp0 0/0 port 6973 -> 10.0.0.2 port 6973 udp
rdr ppp0 0/0 port 6974 -> 10.0.0.2 port 6974 udp
rdr ppp0 0/0 port 6975 -> 10.0.0.2 port 6975 udp
rdr ppp0 0/0 port 6976 -> 10.0.0.2 port 6976 udp
rdr ppp0 0/0 port 6977 -> 10.0.0.2 port 6977 udp
rdr ppp0 0/0 port 6978 -> 10.0.0.2 port 6978 udp
rdr ppp0 0/0 port 6979 -> 10.0.0.2 port 6979 udp
rdr ppp0 0/0 port 6980 -> 10.0.0.2 port 6980 udp
rdr ppp0 0/0 port 6981 -> 10.0.0.2 port 6981 udp
rdr ppp0 0/0 port 6982 -> 10.0.0.2 port 6982 udp
rdr ppp0 0/0 port 6983 -> 10.0.0.2 port 6983 udp
rdr ppp0 0/0 port 6984 -> 10.0.0.2 port 6984 udp
rdr ppp0 0/0 port 6985 -> 10.0.0.2 port 6985 udp
rdr ppp0 0/0 port 6986 -> 10.0.0.2 port 6986 udp
rdr ppp0 0/0 port 6987 -> 10.0.0.2 port 6987 udp
rdr ppp0 0/0 port 6988 -> 10.0.0.2 port 6988 udp
rdr ppp0 0/0 port 6989 -> 10.0.0.2 port 6989 udp
rdr ppp0 0/0 port 6990 -> 10.0.0.2 port 6990 udp
rdr ppp0 0/0 port 6991 -> 10.0.0.2 port 6991 udp
rdr ppp0 0/0 port 6992 -> 10.0.0.2 port 6992 udp
rdr ppp0 0/0 port 6993 -> 10.0.0.2 port 6993 udp
rdr ppp0 0/0 port 6994 -> 10.0.0.2 port 6994 udp
rdr ppp0 0/0 port 6995 -> 10.0.0.2 port 6995 udp
rdr ppp0 0/0 port 6996 -> 10.0.0.2 port 6996 udp
rdr ppp0 0/0 port 6997 -> 10.0.0.2 port 6997 udp
rdr ppp0 0/0 port 6998 -> 10.0.0.2 port 6998 udp
rdr ppp0 0/0 port 6999 -> 10.0.0.2 port 6999 udp

However, every stream I opened would die within one minute.  It was 
as if packets were not making it to my machine - my modem lights 
would be flashing like mad, but the streaming movie (or sound file) 
would just stop!  I checked and re-checked everything I could think 
of, then looked into ipf.conf, and started wondering if it should 
really be blank.  For the heck of it, I defined it like so:

allow in all
allow out all

Voila!  Streaming now works reliably!  All packets make it to my 
computer!  So wherever anyone has written that the ipf.conf file can 
be left blank in an IP-NAT setup, it should be corrected.  Everyone 
should at least have the following in that file.  I don't know if it 
affects anything else, but it only makes sense that its properly 
defined.

Anyone have any progress to report on compiling that RTSP proxy?
--
nathan raymond
webmaster <a href="http://www.everythingmac.com">everythingmac.com</a>