Port Mapping

Port mapping (or Port Address Translation - PAT) is the process where the packets arriving at the interface are checked by port number and the IP address they want to reach. Based on port numbers, an IP address finds these packets forwarded to the pre-defined private class IP address on the local network.

WebAccess uses Active Server Pages (.ASP) to communicate with an Access database for engineering and configuration (typically via TCP Port 80).  Real-time Data and Animated Graphics are supplied to client Web Browsers using an ActiveX "plug-in" to Internet Explorer 6.0 (the default ports are 4592 and 14592, respectively).

Project Node IIS Web Server Port (default 80)<-private ipaddress -> Proxy Server Third Port (3333 in example) | <--Internet --> router ip:port

Project/SCADA Node Primary Port (default is 4592)  <--private ipaddress --> Proxy Server      |<----  Internet ----> deploy file tells CLIENT

SCADA Node Secondary Port (default is 14592) <--- private ipaddress ---> Proxy Server |<----  Internet ----> deploy file tells CLIENT   

At least three TCP Ports must be mapped, assuming both the SCADA Node and Project Node are the SAME COMPUTER on a private network (i.e. intranet) and are using a Router or Proxy Server: Two ports to the WebAccess software SCADA Node/Project Node's Primary and Secondary Ports and to map one port to the Web Server port of the Project Node. The WebAccess Primary Port is Mapped to both the Project Node and SCADA node's Primary Port and the WebAccess secondary port to just the SCADA Node' secondary port.  These three TCP ports all have the same private IP address, just different port numbers.

WebAccess downloads a "deploy file" which describes the two additional TCP ports used by Web Access Project and SCADA Nodes to the Clients.  This deploy file contains the address of the SCADA Nodes and Project Node.  This address used in the deploy file must be translatable by all your users.

The design of WebAccess using Port Mapping requires that the Router/Gateway redirect Private IP Users back to the SCADA Node and Project node when the Public IP:Port is used by the Private IP User (including the SCADA Node and Project Node).  Most Routers do this (LinkSYS and CISCO), we believe. This is the second customer to have difficulty. 

To configure a access to the Project Node and SCADA Node, for most routers/gateways, enter the Public IP address in SCADA Node and Project Node configuration.  Most routers will translate the Public IP Address into a Private IP Address for both External (Public, Internet) and Internal (Private, Intranet) Users.

Many ADSL modems and Novell Border Manager does not connect internal users back to the internal node if a Public IP address is specified by the private user . If the router/gateway does not re-direct internal users to an internal node using a Public IP address, then the HOSTS file is a solution that allows different users to interpret the SCADA and Project Nodes differently.  A HOST name is entered in Project Configuration, instead of an IP Address, for the SCADA and Project Nodes.

3 TCP Ports must be mapped to the Project / SCADA Node. The default Port Numbers are:

1)     Port 80 is the default Port used for the ASP page (the web page).

2)     Port 4592 is the WebAccess Primary Port used for File Downloads (e.g. graphics, symbols, etc). 

3)     Port 14592 is the WebAccess Secondary port is used for real-time data (e.g. setpoints, measurements, status, Trends).

You will have to contact the system administrator that runs the intranet and the Router or Proxy Server.  He must map ports from the router / proxy server to the Project Node and SCADA Node(s) addresses.  You must configure the WebAccess Project Node and  SCADA Node(s) to use those TCP Ports as the WebAccess Primary and Secondary Ports.  IIS (Internet Information Server) on the Project Node must be configured to use the Third Port. The easiest is to map port 80 of the WebAccess Project to the third port. This allows other users on the intranet to see the WebAccess Project node without specifying another port.  Alternatively, IIS can be configured to use another Port so that all users can address the Project and SCADA nodes similarly.

The outside clients will use the Proxy Server's IP Address with the third ports IP appended to it.

Clients will type in the IP Address of the Proxy Server : 3rd Port.  If the third TCP Port is 3333  and the IP address of the Proxy Server is then Internet Clients must enter for the IP address

WebAccess downloads a "deploy file" which describes the other two TCP ports to the Clients.  Port *) is used for the ASP page (the web page), The Primary Port is used for File Downloads (e.g. graphics, symbols, etc).  The Secondary port is used for real-time data (e.g. setpoints, measurements, status, Trends).