Poor IPSec Site to Site Speed

I have an Problem with poor throughput within an IPSEC Site to Site.



ASG1 v8.300 <--------> ASG2 v7.511
16Mbit ADSL <--------> 20Mbit up/down

Ipsec Site to Site with PSK and AES 256bit Encryption.

Throughput only 2Mbit per second. :mad:

ASG1=D525MW, 4GB Ram with all Hardware in HCL certified.
ASG2=DL380G4, 4GB Ram with all Hardware in HCL certified.


Now the strange thing which I can not understand:

- If I use my Cisco 870 Router instead of the ASG1 i get the full throughput with no limit. :confused:

- If I install the ASG1 in an virtual machine on my Vmware Workstation i get also unlimited throughput. :confused:


That isolates the problem for me into the ASG1 with D525MW, Board.
In the config is no QOS with Bandwidth Limit configured.
The Internet Lines are everytime the same.


Any Ideas?


Thanks in advance.