Set up TCPListener

Network Placement

The TCPListener application is installed with the AVEVA Enterprise SCADA Administration Tools. Install the TCPListener software on the network in a location where it can directly eavesdrop on communications between the source system and the field units.

There are numerous potential locations. One of the most feasible options is to place it on the same subnet as the source system. Alternatively, one could place it on the same subnet as the field units.

Note: The validity of these suggestions depends entirely on the network architecture and the security arrangements of the customer in question. The project team should work closely with the customer’s Network Administrator to determine the best location.

Important: TCPListener is limited to use of a single network interface for eavesdropping. The chosen location must be a place where it can also access the listening system.

Switch Configuration

The computer where the TCPListener software runs must be connected to a switch between the current source system and the field units. To allow TCPListener to receive packets intended for other parties, set the Network Card (NIC) to promiscuous mode. In some cases, even when the NIC is set correctly, the switch will prevent unauthorized computers from sniffing packets. If this situation arises, follow the manufacturer instructions to configure the switch for port mirroring to allow the TCPListener computer to receive this traffic.

Protocol Configuration

For the listening system to process the packets it receives from TCPListener, configure the protocols for Listen Only mode. Refer to Listen Only.

Operating Environment

The TCPListener software runs as a Windows process with local Administrator privileges on a Windows computer.

Limitations

• The TCPListener software:

  • Only listens to and processes IPv4 traffic.

  • Only listens to a single local network interface.

  • Delivers the payload of the interested TCP packet without additional operation on the payload.

  • Processes the TCP packets in a First-In, First-Out (FIFO) manner.

• Most Omnicomm protocols with Listen Only mode can only support RealTime polling. In other words, no, for example, setpoint commands or Gas History Uploads.

Connection Methods

TCPListener and the listening system can connect to one another using either of the following methods:

• Server Port: Listening system connects directly to ports on TCPListener. TCPListener is the server, while, on the listening system, Omnicomm is the client.

• Relay Service: Listening system connects to a port pair provided by the OASyS DNA Socket Server Relay Service running on the listening computer. TCPListener then connects to the matching port. TCPListener is the client, while, on the listening system, OASyS DNA Socket Server Relay Service is the server.

If a firewall exists between the computer where the TCPListener software runs and the listening system, open ports to facilitate communication:

• If using Server Port mode, open ports on the domain where TCPListener is located to allow the listening system to connect to it. The ports that need to be opened correspond to the "WritePort" in the TCPListener XML file.

• If using Relay Service mode, open ports on the domain where the listening system is located to allow TCPListener to connect to it. The ports that need to be opened correspond to the "RelayService" in the TCPListener XML file.

For further information, refer to Configure the TCPListener XML file. There is no requirement for a connection port on the listening system to match the port used on the current source system. Customers should consult with both an AVEVA Enterprise SCADA Administrator and a Network Administrator for this configuration.