do you know what are supported network transport protocols by aix 5.2?

I connected two networks that are far about 500 KM with a 100Mbit/s
line but I have performance problems: udp's speed is about 11MB/s and
tcp's is only 4MB/s.

The difference is due to tcp control packets.

Because of this I'm looking for another transport protocol: I found S-
shaped TCP but I don't know if it's supported by aix.

Do you have suggestions?


Marco Strullato