VRReaderNetworking

VR Network Management

• ModemManager
• NetworkManager
• VRConnectionManager

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The network interface of the VR Reader board

Requirements

• support network devices for: ethernet, wifi, and cellular.
• also, support restarting the afflicted device on the hardware side if needed.
• (optional+) auto switch between cell and wifi if both are in view.
• WIFI support for WPA2 / Enterprise Wifi like PEAP/MSCHAPv2/etc.

Software side options

• Use wan.sh shell script like we used for ASD with the USB 760
  • Pros: very robust
  • Cons: only works with the USB 760, slow (can take >30s to connect/reconnect).
• Connman (from maemo side, reaction against NetworkManager? being a pain to configure and extend)
  • Pros: seems simple, straightforward, built for embedded devices, DBus configuration
  • Cons: no documentation, no command-line tools, somewhat maemo-specific, DBus configuration
• NetworkManager? (standard on the desktop side for a while, support is improving a lot after connman was created :) )
  • Pros: lots of docs, example code, supports a ton of 3g modems, large distro support
  • Cons: complex, desktop-focused, needs a dbus configuration provider.

NetworkManager investigation

After looking into NetworkManager for a bit, it will definitely work for our needs, however we will need to write (or look for) a daemon that manages networkmanager. It would be responsible for choosing the best ethernet connection based on its current configuration and the current network options. It would be nice to take some other things into account too, like GPS location or cell modem signal strength.

It also needs to be able to handle errors I would hope would be thrown when the modem is not responding or other problems and could restart hardware devices / re-add/re-configure with networkmanager and get things going again. This also means a lot of testing would have to be done for these cases.

networkmanager ignore ethernet device (for NFS)

/etc/NetworkManager/nm-system-settings.conf

[keyfile]
unmanaged-devices=mac:f8:dc:7a:00:00:00

Updates

KMB 20120305 - brain dump after testing out networkmanager for a bit; and for the first Rehrig shipment we will be using 3 USB760/shell script units.