VintageNetECM

A VintageNet technology for cellular modems whose data plane is a USB CDC-ECM (or RNDIS) network interface — for example the Quectel EG800Q in usbnet ECM mode.

Unlike VintageNetMobile, which dials a PPP link over a serial AT port, an ECM-class modem exposes an ordinary Ethernet-like netdev (usb0/usb1/wwan0) whose IP/DNS/route are obtained over DHCP once the modem's internal data call is up. VintageNetECM therefore composesVintageNetEthernet for the IP plane and adds an AT-control sidecar that brings the modem's data call up and reports registration and signal.

The vendor-specific AT details live behind the VintageNetECM.Modem behaviour. The default implementation, VintageNetECM.Modem.Quectel, targets Quectel usbnet ECM modems.

Installation

Add vintage_net_ecm to your list of dependencies in mix.exs:

def deps do
  [
    {:vintage_net_ecm, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/vintage_net_ecm.

Configuration

VintageNet.configure("usb1", %{
  type: VintageNetECM,
  vintage_net_ecm: %{
    service_providers: [%{apn: "super"}],
    at_tty: "ttyUSB2",
    context_id: 1
  }
})

• :service_providers — required, a non-empty list of maps with a string :apn. The first provider's APN is used.
• :modem — the VintageNetECM.Modem implementation (defaults to VintageNetECM.Modem.Quectel).
• :at_tty — the AT control tty (defaults to the modem's default_at_tty/0).
• :context_id — the PDP context id (defaults to 1).

:ipv4 defaults to %{method: :dhcp} — the only sensible mode for ECM. Other VintageNetEthernet options (:dhcpd, static :ipv4, :mac_address) pass through to the composed ethernet config.

Supporting another modem

Implement the VintageNetECM.Modem behaviour and pass it as :modem. Only the data-call control and access-technology reporting are vendor-specific; the rest of the lifecycle uses standard 3GPP commands.