Compact Logix PLC(L32 V19) and wonderware Intouch 9.5 through VPN

Hi all,

I have a problem with wonderware 9.5 comms over VPN..

We have a set-up where we connect Scada and two PLC'S through VPN connection.

I have found that I can ping the PLC 's from Scada Station but neither its communicates with Rslinx nor with wonderware

Following are the error showing in RS Linx Event Log
07/24/13 22:51:39 192.168.1.10 Unable to establish TCP connection to the Ethernet Interface
07/24/13 22:51:39 192.168.1.10 [10060] Connection timed out
07/24/13 22:51:39 192.168.1.10 CSPv4 connection lost; timed out on socket write
07/24/13 22:51:39 192.168.1.10 Device refused a CSPv4 connection, retry using EtherNet/IP
07/24/13 22:51:39 192.168.1.10 Attempting first connection, protocol = EtherNet/IP
07/24/13 22:52:00 192.168.1.10 Unable to establish TCP connection to the Ethernet Interface
07/24/13 22:52:00 192.168.1.10 [10060] Connection timed out
07/24/13 22:52:00 192.168.1.10 EtherNet/IP connection lost; timed out on socket write
07/24/13 22:52:00 192.168.1.10 Device refused an EtherNet/IP connection, retry using CSPv4
07/24/13 22:52:10 192.168.1.10 Attempting first connection, protocol = CSPv4
07/24/13 22:52:31 192.168.1.10 Unable to establish TCP connection to the Ethernet Interface

Our Scada System in wonderware Intouch 9.5 and PLC'S are compact Logix L32E
We are using Viola m2m Gateway (Scada) and 2 Viola Arctic Router(PLC's) for VPN Tunnel Network.

Is there any port forwarding required?
Is there any firewall issue?
Regards
Joseph