WAF only 128bit SSL

Hi,

i have one ASG that only uses a RC4 encryption 128bit. I guess its a revision 4, Firmware 8.309.
All of my Rev. 5 and UTM9 are using Camellia 256bit encryption.

Does the encryption algorythm depend on the ASG revision or is it a bug in my machine?

Thanks for your help (hope my english was not to bad).