Examples of Client/Server Architecture

This section describes some example architectures applied for web-based solutions and provides information on how to configure the project for each architecture. This section does not describe all possible architectures, but it provides the concepts necessary to design and configure different scenarios based on the basic architectures illustrated below

The Web Settings are configured by the Web tab of the Project Settings dialog. To open this dialog: on the Project tab of the ribbon, in the Web group, click Thin Client. By pressing the Advanced button, you access additional settings. The following pictures illustrate these dialoges:

The following table describes the meaning of the main Web settings illustrated in the above dialoges:

Setting	Description
Data Server IP Address	When the Web Tunneling Gateway is disabled: The Thin Client Control (ISSymbol) uses the Data Server IP Address to connect to the IWS TCP/IP Server Task. When the Web Tunneling Gateway is enabled: The Web Tunneling Gateway uses the Data Server IP Address to connect to the IWS TCP/IP Server Task.
Secondary Data Server IP Address	Same as the Data Server IP Address. However, the Secondary IP Address is used only when the connection with the Data Server IP Address fails.
Web Tunneling Gateway IP Address	The Thin Client Control (ISSymbol) uses the Web Tunneling Gateway IP Address to connect to the Web Tunneling Gateway.
Web Tunneling Gateway Secondary IP Address	Same as the Web Tunneling Gateway IP Address. However, the Web Tunneling Gateway Secondary IP Address is used only when the connection with the Web Tunneling Gateway IP Address fails.

The Secondary addresses can be used in the following scenarios:

When the Thin Clients can connect to either one of two redundant Servers (Web or Data); or
When the Thin Clients can connect to the Server through the Intranet (LAN – Local Area Network) or through the Internet (WAN – Wide Area Network). In this case, the Primary addresses should be configured based on the network used more often by the Thin Clients. In the following examples, the LAN addresses are used as Primary and the WAN addresses are used as Secondary.

The following table describes the meaning from some terms used in the next examples:

Term	Description
LAN	Local Area Network (for example, Intranet)
WAN	Wide Area Network (for example, Internet)
Server	Station where the following components are running: IWS (TCP/IP Server task) Web Server (for example, Internet Information Services from Microsoft – IIS) Web Tunneling Gateway for IIS (if enabled) Although IWS does not need to run in the same station where the other components are running, the following examples assume that it is.
Thin Client LAN	Thin Client station (Web Browser + ISSymbol control) that connects the Server via the LAN.
Thin Client WAN	Thin Client station (Web Browser + ISSymbol control) that connects the Server via the WAN.
IP_SERVER_LAN	IP Address of the Server on the LAN.
IP_SERVER_WAN	IP Address of the Server on the WAN.
IP_ROUTER_LAN	IP Address of the Router on the LAN.
IP_ ROUTER_WAN	IP Address of the Router on the WAN.
ScreenName	Name of the project screen, saved as HTML, that is open on the Thin Client station.

Example 1: Web Server and Thin Client in the same Intranet (LAN)

Figure 1.

This is the very common architecture, as well as the simplest to configure. In this architecture, both the Web Server (e.g., Microsoft IIS) and the Data Server (i.e., the IWS TCP/IP Server module) are running on the same PC. The Thin Client connects to the Web Server to download the HTML screen file(s). Then it connects to the Data Server to exchange data with the IWS runtime project. Since both the Thin Client and the Server station are connected to the same network, the Thin Client can access the Server station directly through its IP address (or host name).

Configuration:

Setting	WTG Enabled	Web Gateway Disabled
Data Server IP Address	IP_SERVER_LAN	IP_SERVER_LAN
Secondary Data Server IP Address	-	-
Web Tunneling Gateway IP Address	IP_SERVER_LAN	-
Web Tunneling Gateway Secondary IP Address	-	-

Note:

URL From Thin Client LAN: http://IP_SERVER_LAN/ScreenName.html
Home directory of the web server (HTTP server) on the server station: Web sub-folder of the project

Example 2: Web Server with Intranet (LAN) and Internet (WAN) Connections

Figure 2.

This architecture has both the Web Server (e.g., Microsoft IIS) and the Data Server (i.e., the IWS TCP/IP Server module) running on the same PC. Thin Clients can connect to the Server through either an Intranet (LAN) connection to the Server or an Internet (WAN) connection to the Server (e.g., two different Ethernet ports).

Configuration:

Setting	Web Gateway Enabled	Web Gateway Disabled
Data Server IP Address	IP_SERVER_LAN	IP_SERVER_LAN
Secondary Data Server IP Address	IP_SERVER_LAN	IP_SERVER_WAN
Web Tunneling Gateway IP Address	IP_SERVER_LAN	-
Web Tunneling Gateway Secondary IP Address	IP_SERVER_WAN	-

Note:

URL From Thin Client LAN: http://IP_SERVER_LAN/ScreenName.html
URL From Thin Client WAN: http://IP_SERVER_WAN/ScreenName.html
Home directory of the Web Server (HTTP server) on the Server station: Web sub-folder of your project folder
You must assign a Fixed IP address to the Web Server on the Internet (WAN), and the project must be running in this Server. Consult your ISP provider or IT department for further information about how to get a Fixed IP address for your Server.

Example 3: Web Server with Intranet (LAN) and Router Internet (WAN) Connections

Figure 3.

This architecture has both the Web Server (e.g., Microsoft IIS) and the Data Server (i.e., the IWS TCP/IP Server module) running in the same PC. Thin Clients can connect to the Server through either an Intranet (LAN) connection or an Internet (WAN) connection. There is a Router between the Intranet (LAN) and the Internet (WAN).

Configuration:

Setting	Web Gateway Enabled	Web Gateway Disabled
Data Server IP Address	IP_SERVER_LAN	IP_SERVER_LAN
Secondary Data Server IP Address	IP_SERVER_LAN	IP_ROUTER_WAN
Web Tunneling Gateway IP Address	IP_SERVER_LAN	-
Web Tunneling Gateway Secondary IP Address	IP_ROUTER_WAN	-

Note:

URL From Thin Client LAN: http://IP_SERVER_LAN/ScreenName.html
URL From Thin Client WAN: http://IP_ROUTERR_WAN/ScreenName.html
The Router must be configured to forward the TCP Port(s) from its public IP (IP_ROUTER_WAN) to the Server private IP (IP_SERVER_LAN).
If the Web Gateway is enabled, only the HTTP Port (80, by default) or the HTTPS Port (SSL Port 443, by default) must be forwarded from IP_ROUTER_WAN to the IP_SERVER_LAN.

If the Web Gateway is disabled, both the HTTP Port (80, by default) and the Studio TCP/IP Server Port (1234, by default) must be forwarded from IP_ROUTER_WAN to the IP_SERVER_LAN. Consult the Router documentation for further information about how to configure Port Forwarding on it.
Home directory of the Web Server (HTTP server) on the Server station: Web sub-folder of your project folder
You must assign a Fixed IP address to the Router on the Internet (WAN), and the project must be running in this Server. Consult your ISP provider or IT department for further information about how to get a Fixed IP address for your Server.