Mobile Protocols

There are two different mobile protocols built-in the 4G 4 router. The default mobile protocol is Mobile Data. Suggest using the default protocol unless your mobile provider does not support it.

Mobile Data Protocol

The Mobile Data protocol is based on QMI, Qualcomm MSM Interface, a proprietary protocol offering more accessible and faster connections to mobile networks.

Due to the difference in the modem chipsets, the different mobile modems might use other QMI proxies. For example, Sierra modems use the QMI_WWAN proxy, and Quectel modems use the GobiNet proxy. These proxies use the same QMI protocol and provide similar working performance.

The primary difference is that GobiNet uses kernel space, while qmi_wwan uses user space. And in qmi_wwan, only one process can handle the control port at a given time, while the GobiNet proxy allows multiple processes to access the device concurrently.

4G-PPP Protocol

PPP, Point-to-Point Protocol, is a traditional data link layer communications protocol. PPP protocol has been very widely used and is most flexible for interoperability with devices.

Some mobile carriers might not support QMI protocol to connect to their mobile networks. We must change the mobile protocol from the default Mobile Data protocol to the 4G-PPP protocol.

Switch to PPP Protocol

Under Common Configuration > General Setup of the Mobile interface, choose 4G-PPP on the dropdown menu of Protocol. Then click the confirm button Switch protocol. It will jump to the 4G-PPP protocol setup page.

Comparing with the Mobile Data protocol, the 4G-PPP protocol has two extra configuration fields, Service type and Dial number. The other parameters, including APN / PIN / Username / Password, are the same configuration operations as the QMI cellular protocol.

• Mobile device: Choose /dev/ttyUSB2

• Service type: Due to differences in mobile network standards, choose the services below:

  • UMTS/GRPS for the UK / European / Australian versions

  • CDMA/EV-DO for the American versions

• Dial number: Use *99# for European standard network, and use *99***1# for American standard networks.

Click Save & Apply button on the bottom right corner to apply the new APN parameters. Then back to Network > InterfacesWait 1-2 minutes until the mobile modem reconnects to the mobile network.

Select "Mobile Data" from the protocol field and click the "Switch Protocol" button to switch the protocol back to Mobile Data. Then, configure the parameters as shown on the default mobile modem settings.