VPN Site To SITE with Public IP

Hello all..

I have a vpn connected between a Sophos SG230 and checkpont firewall (The client).
The most headache part, the client wants all my traffic to be translated as my Public IP.
I've manage to establish the VPN connection with the SNAT ( to configure Local LAN as external public IP with traffic outgoing to client destination.

The question,

When the client tried to ping and telnet the source IP (from our end), result return "Request Time Out". Could anyone guide me how to configure the incoming traffic?

Thousand Thanks!
Mr. J