I have an ASA 5505 at 192.168.1.252. There's a provider managed MPLS router at 192.168.1.1. A host at 192.168.4.17, across the MPLS, has a cam system at port 8000.
From the 192.168.1.0 subnet I can reach 192.168.4.17:8000. I added PAT on the ASA for this port, and PAT works fine for hosts on the 192.168.1.0 subnet. There is a route on the ASA to the 4. subnet. There is an access-list assigned to NAT (inside) 0:
access-list nat0_acl extended permit ip 192.168.1.0 255.255.25.0 192.168.4.0 255.255.255.0
So, I know the port traffic is already traversing the MPLS. Does anyone know how I pass through the port forward from the ASA through to the other side of the MPLS?