FreedomBox for Communities/ADSL Modem

The Wi-Fi network setup for the community needs to get Internet connectivity from an ISP or another community. It can then distribute that connection for the benefit of all the members of the community. One of the ways to connect a home network or a community network to the Internet is via a technology known has ADSL. When using ADSL, an ISP provides the Internet connectivity using a telephone line and then uses an ADSL modem on the subscriber's (in our case the community) end to convert the signals on the telephone line to something a typical computer can understand. While ADSL technology is becoming rare, there are many ISPs still providing connections using ADSL especially in rural areas.

This section describes how to connect a community Wi-Fi network setup using FreedomBox to Internet assuming the ISP is providing Internet connection using ADSL. While there are many different models of ADSL they operate on similar principles and provide similar functionality. This section uses one such modem the authors encountered as an example and describes the setup process. A reader must adopt these instructions to other ADSL modems based on the concepts described here.

An ADSL modem has on one end has a port to plug-in the telephone line from the ISP. It is receives the Internet connection from that port. On the other end, it has a single (sometimes multiple) port to connect to a single computer or an entire network. This is the Ethernet port and is used to distribute the Internet connection to the computers that need it. Some ADSL modems also have the ability to create Wi-Fi network on which they distribute the Internet connection they receive from the ISP.

An ADSL modem is most often provided by an ISP or is purchased separately by the subscriber. This modem is typically pre-configured but requires additional configuration for optimal use with FreedomBox community networks. The following are the steps to follow for configuring the modem.

Accessing Configuration Interface

Power the ADSL modem and wait for it fully boot by giving it about 5 minutes.
Connect to the Wi-Fi network of the modem using the access point name and password provided in the manual or printed on the modem. If this information is not available, search for it on the Internet using the make and model of the modem. If the information provided in the manual does not work, try resetting the modem. The reset procedure is described in the manual which can be downloaded from the Internet using the make and model of the modem.
Not all ADSL modems have a Wi-Fi network to connect to. If Wi-Fi network is not available, then connect a patch cable from a computer to the modem. The patch cable is provided along with the ADSL modem, otherwise purchase and use a regular Ethernet cable. The modem will automatically allocate an IP address to the laptop. This will typically be in the range 192.168.1.1/24.
Open the browser and visit the URL http://192.168.1.1/. This address could be different for different modems. Check the manual of the ADSL modem for the correct address. Some modems also give a special name that can be used to reach the modem.
Login in to the web interface as an administrator. When logging in for the first time, the router may allow the user to create an administrator account. Otherwise, the default password is made available in the manual or printed as label on the modem. For example: username: admin, password: admin.
Visit the status page. This page provides information for the device. For example:
1. Company Logo: Syrma Technology
2. Model: DSLW200-SY
3. Software Version: 2.1.1
4. Hardware Version: 1.1

Administration Password

For security reasons, change the administration password immediately.

Go to Maintenance and then Administration.
New Password: [community admin password].
Confirm Password: [community admin password].

Internet Configuration

This section is to configure the modem such that it is able to receive the Internet connectivity properly. ADSL modems have a port to input the telephone line into the modem. First the telephone line provided by the ISP should be connected into this port.

As for configuration, many times, the Internet configuration is automatically done by ISP when they provide the ADSL modem. If so, leave it as it is. It is useful to write down the current values so that we can reconfigure in case of a reset to factory settings. If ISP has not configured the modem already, they will enable the modem to configure itself automatically. In the absence of that, they provide the configuration information. Use that information to configure the modem.

Network Configuration

This section is to configure the ADSL modem to distribute the Internet connection it receives to the community network. More specifically to FreedomBox which then distributes the Internet connection further to all Wi-Fi access points and the clients connecting to those access points.

Add an IP address in addition to the existing IP address.

Go to Interface Setup and then LAN.
In addition to the existing IP address, add an IP address that is suitable for FreedomBox network. Say:
1. Alias IP Address: 10.42.0.4
2. Alias Subnet Mask: 255.255.255.0
Save configuration.

FreedomBox will also be provided an IP address in the same range such as 10.42.0.1. FreedomBox will be sending all the packets that are destined for machines on the Internet to this modem by setting the default route to 10.42.0.4.

Wi-Fi Configuration

Wi-Fi network is not used and may be disabled. If Wi-Fi is not available on the ADSL modem, ignore this step. This is because we shall be setting up more powerful Wi-Fi access points that will be available on larger range and provide roaming.

Go to Interface Setup and then Wireless.
Access Point: Deactivated

If wireless access is needed, then keep the existing configuration and set a better and stronger password.

Pre-Shared Key: [random password]

Forward All Traffic to FreedomBox

FreedomBox can host services such as wiki and digital library that can be accessed by members of the community when they are away from the community network, for example, during travel. Some of these services are also meant to be accessed by non-community members on the Internet. For this to work the ADSL modem must be configured to forward all the requests it receives from the Internet to the FreedomBox which then responds to the request.

This setup will only work when the ISP provides a public IP address to their subscribers with each subscription. In cases they don't provide a public IP address by default, they may do so when requested for an additional monthly fee. Check with your ISP if they provide an public IP address by default or for an extra fee.

Without this configuration FreedomBox can't be easily be reached from outside the Internet. After setting up the below, FreedomBox will receive all the external traffic on all the ports. Hence, services such as Web (80, 433), SSH (22), Mail (25, etc.) will all be forwarded to FreedomBox automatically.

Go to Advanced Setup then go to NAT and click on DMZ.
Set the following and save.
1. DMZ: Enabled
2. DMZ Host IP Address: 10.42.0.1 (FreedomBox's IP address)

In case DMZ feature is not available in your modem or if it does not work as expected, another feature known as port forwarding can be used to achieve the same goal. Depending on the services deployed on FreedomBox, it will notify you of the ports that need to forwarded. For each of those ports, add a entry in the modem's port forwarding configuration page with external port number and internal port number set to the same port number provided by FreedomBox. Then set the IP address to forward to as FreedomBox's IP address, that is 10.42.0.1.

Backup

Take a backup of the ROM file. Just in case you need to reset the modem in future, you can quickly restore from the backup instead of configuring all the above.

Go to Maintenance and then Firmware.
Click on Romfile Save and save the file.