VPN

I have setup a site-site vpn between to mono boxes, But only one way traffic works... not sure why is this happening....

Site A Mono :
LAN IP 10.117.1.10/24
Static Route : 10.115.0.0/16 gw 10.117.1.1 ( vlan connected to switch )
VPN LocalNet & Remote Net : 10.115.0.0/16,10.57.1.0/24

Site B Mono :
LAN IP : 10.57.1.0/24
VPN LocalNet & Remote Net : Local Subnet, 10.115.0.0/16


Problem :

- First of all, only when i try to initiate a traffic for the site A from site B, only then the vpn comes/shows up on the mono....

- Secondly, only one way traffic works ie... from Site B - Site A works, but from Site A to Site B doesn't work... No host based firewall on the client.. Also a trace from the Site A 10.115.1.1 to Site B IP 10.57.1.2 shows that i goes via internet and then unrecheable after couple of hops...

Find the network diagram for review