NAT doesn't seem to work

[Bladman]

Hi,

I currently have issues with a DVR not accessible from the WAN.
The situation is as follows:

• pfSense box has public IP on WAN interface
• LAN has 192.168.20.x as LAN
• DVR has 192.168.20.3 as IP

I have forwarded port 81, with automatic rule generation.
When I perform a online port scan, on port 81, I get a positive result that port 81 is listening.

When I try to access the DVR from the web, on port 81 (web viewer), the browser just keeps hanging on "connecting…" until it times out (tested multiple browsers)
When I telnet to port 81 of the WAN IP, I get connection, and after 2x enter I get a "bad request" so the DVR seems to be listening properly and not "getting" my request.

That strange thing is, the LAN where the DVR is connected, has an IPSEC connection to a branch office. Through the VPN, on IP address 192.168.20.3:81 in the browser, I do get the login screen for the DVR.

Currently I am our of options. The only thing is, the DVR isn't managed by myself, so I don't know the network settings such as the gateway.
It should be good (I guess) since a port scanner and a telnet DO work properly.

Anyone has some suggestions?

Edit:

In addition, another device on the same subnet works fine with NAT port forwarding.. That device is listening on port 3201, and is accessible from the WAN IP:3201 in the internet browser. Just to make sure before I call the guy that manages the DVR, I want to run this by you.

The guy that should check the DVR through the web interface stated that everything was working fine yesterday though with the DVR.

[Bladman]

I just have tested from another location.
There I do get the web interface for the DVR..

From multiple connections I cannot reach the DVR, and from some locations I can…

Someone has any ideas?