# Mobile Protocols

There are two different mobile protocols built-in the EZR24 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*, which is a proprietary protocol that offers more accessible and faster connections to mobile networks.

Due to the difference in the modem chipsets, the different mobile modems might use different 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. So 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 as 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` > `Interfaces`, and wait 1-2 minutes until the mobile modem reconnects to the mobile network. 

![Switching EZR24 Router to Use PPP Protocol](https://2031239798-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FXrJBTozkgaqqeDtauCDH%2Fuploads%2FgcLVCzJ1iGVVx0R5kGrL%2F4G-Router-Firmware-Switch-to-PPP-Protocol.jpg?alt=media\&token=1c5a83d4-2911-4770-8661-65dbcd94f1dc)

{% hint style="info" %}
To switch the protocol back to Mobile Data, select "Mobile Data" from the protocol field and click the "Switch Protocol" button. Then configure the parameters as shown on the default [mobile modem settings](https://ezr24.outdoorrouter.xyz/manual/3-firmware/3.4-mobile-modem).
{% endhint %}