Using Channel 8 Over the Internet


If you have a static IP address, a broadband Internet connection and a typical router, you can use the Channel 8 data logger over the Internet from anywhere in the world. It is a straightorward process to configure your router's firewall for virtual servers to include the Channel 8 PC. This Tech Note will show how to configure a typical router and test Channel 8 over the Internet using a proxy server.

A Typical LAN with Static Internet IP Address

A typical system including broadband Internet connections and a static IP address is shown here. The outside Internet connection might be DSL or cable, but a modem translates the signals into a format suitable for the router and PCs on the LAN.

The router has an address on the LAN, in this case The router determines the destination of the data going to and coming from the PCs on the LAN. The router assigns a local IP address for all PCs on the network and includes a firewall that passes or blocks data depending on the destination and port number.

Configuring the Channel 8 PC for the Internet

In this example we will use a PC running Slax+8. Slax is a portable Linux distribution that self-configures the PC to a LAN on boot-up. Slax+8 is a customized distribution that also contains the Channel 8 data logger as well as FTP and Telnet servers. Slax+8 will ask for an IP address from the router as it boots. The Channel 8 web server will launch automatically under Slax+8 and be ready to receive requests on port 80 (the standard http server port). The Telnet and FTP servers will use port 22 for SSH communications.

If you are using a different Linux distribution, simply point the gateway at the router's IP address. The Linux ifconfig and route commands are used to set the static LAN IP and other network parameters of the PC.

Configuring the Router

For the Slax+8 PC to be accessible from the Internet, the router must be configured for virtual servers. Most routers have a user-interface that can be accessed by a browser. Simply set your browser address to the router: and log in. Be sure to have your browser manual handy so you can use the correct log-in name and password,

Caution: Do not change the Router IP address or DNS Address Settings! Unless you know what you are doing, you might not be able to get back on the Internet.

Navigation of the router's configuration screens vary by manufacturer, but they are generally easy to follow. You want to configure the virtual servers, so you must navigate to that screen in the router's setup. The sample screen, shown here, is an example of a typical virtual server configuration page.

Configuration of the virtual servers is straightforward. For the Airlink router in this example, the various servers are selected from a list box on the top of the page. In this screen shot, the web server is configured at port 80 (the standard default). The Slax+8 PC LAN IP address for this server is selected from a drop-down or by entering the IP address directly -

So this screen shows that the Slax+8 PC at LAN IP address will be allowed to act as a webserver by the router for requests coming from the Internet to static Internet IP address Obviously, only one PC at a time on the LAN can be the webserver for the Internet from this static IP and this is why the router must be configured for the Slax+8 PC.

Similarly, the Telnet and FTP servers, both at port 22 for secure SSH communications, are set to the Slax+8 PC LAN address at Be sure to update the virtual server settings to your router's non-volatile memory so the settings are saved in case of a power failure.

Testing Internet Access

Once the router is configured for virtual servers on the Slax+8 PC, and the Channel 8 servers are up and running, it is time to test the system.

The first obvious step is to verify operation of the Channel 8 servers over the LAN. To do this, launch a browser on a Windows PC on the LAN and set the address to: Since the Windows PC is on the same LAN and behind the router firewall, you should quickly see the Channel 8 opening screen in the browser.

To test the outside Internet access to the Slax+8 PC will require the use of a proxy server. A PC on the same LAN cannot set its browser to the static Internet IP address: the request will not be passed by the router. So a proxy server is used. A proxy server is simply another Internet site that will re-route your browser's request through its own static IP. So your webpage request to your Internet IP address looks like an external request and it will be passed by your router to the virtual webserver you just configured.

One proxy server that can be used is at

You simply put this address into your browser, and provides a box for the website URL or IP address you want to view by proxy. You may have to ignore the advertisements - that is the price of a free proxy server.

Enter the your static IP address into the anaonymouse URL box:

If everything has been configured correctly, you should see the Channel 8 opening screen.

Naturally, if you are outside of your own LAN, you will not have to use the proxy server. It should be possible to connect by simply setting the broswser address to

Congratulations! You now have a data logging system accessible by Internet from anywhere in the world.