IPSec VPNs Debit less than 30Mbps

Dear all

We get some issue with our Sophos XG105

We got 2 XG 105 on 2 sites. The 2 sites are connected in fiber channel :

Site 1 : 100M

Site 2 : 200M

On datasheet we can see that VPN allows about 300Mbps of debit on IPSec connexion

But when i launch a file transfer from site1 to Site2, i cannot get a speed transfer more than 3 or 4 Mo/s. Logically i think i should have file transfer speed about 11Mo/s with my configuration.

I Tried it with other sites and got the same results (on other client configuration but with same kind of internet connection : XG105 on fiber channel between 100M and 200M)

I also tried to modify configuration of my IPSec policy : trying a lot of propotocol combinaison.... always the same results

My question : does anyone get file transfer speed more than 3Mo/s on XG105????

Complementar informations : 

- No security appllied on my firewalls rules (lan to vpn / vpn to lan)

- Tryed with following :

P1 : AES256 / SHA1 / DH2  // P2 : AES128 / MD5 / DH2

P1 : DES / MD5 / DH2 // P2 : DES / MD5 / DH2

Those 2 configurations gets same result

I would like to be able to get 10Mo/s on file copy on my two sites (wich mught be able with my configuration)

Any ideas?

Let me know

BR

Sylvain