Chapter 6. Tunnelling Scenarios
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Chapter 6. Tunnelling Scenarios

Table of Contents
6.1. Tunnelling - Firewalls Open
6.2. Tunnelling - One Firewall Closed
6.3. Tunnelling - Both Firewalls Closed, with DMZ
6.4. TCP Ports and DataHub Tunnelling

6.1. Tunnelling - Firewalls Open

Tunnel Scenario 1 - Firewalls open, read-only

Primary Use  Connect OPC DA or A&E on a secure network, avoid DCOM (monitoring only).

Configuration Configuration
OPC Client: Configure this DataHub instance as an OPC client to the OPC server.  OPC Server: Configure this DataHub instance as an OPC server for the OPC client.
Tunnel Master: Configure this DataHub instance as a Tunnel master, to receive connections.  Tunnel Slave: Configure this DataHub instance as a Tunnel slave, so that it initiates the connection.
  
Data Flow Direction:
Read-only
When Connection Initiated:
Get all values from Master
When Connection Lost:
Mark data here “not connected”

See also Tunnelling Security - Best Practices.

Tunnel Scenario 2 - Firewalls open, read/write

Primary Use  Connect OPC DA or A&E on a secure network, avoid DCOM (monitoring and supervisory control).

Configuration Configuration
OPC Client: Configure this DataHub instance as an OPC client to the OPC server.  OPC Server: Configure this DataHub instance as an OPC server for the OPC client.
Tunnel Master: Configure this DataHub instance as a Tunnel master, to receive connections.  Tunnel Slave: Configure this DataHub instance as a Tunnel slave, so that it initiates the connection.
  
Data Flow Direction:
Read-Write
When Connection Initiated:
Get all values from Master
When Connection Lost:
Mark data here “not connected”

See also Tunnelling Security - Best Practices.

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5.5.3. Partial data sets Home 6.2. Tunnelling - One Firewall Closed