# qmi, mbim, ncm, rndis



## balanga (Mar 18, 2018)

I'm trying to follow this guide for setting up Internet access via a USB modem and am immediately presented with three options:-

qmi and mbim, see How To Use LTE modem in QMI mode for WAN connection
ncm, see How To Use LTE modem in NCM mode for WAN connection
rndis, see How To Use LTE modem in RNDIS mode for WAN connection

Unfortunately I don't really know anything about these different access methods and would prefer someone to tell me which I should choose.

Any guidance would be appreciated.


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## Phishfry (Mar 18, 2018)

The Sierra modems have a method to switch modes. They call it usb compositions.
My modem can do many of the modes but works with FreeBSD via MBIM.


So if you notice I am using usbcomp=8
8  - DM   NMEA  AT    MBIM                        SUPPORTED
DM=Managment Port
NEMA=GPS
AT=AT Command Console
MBIM=DATA PORT

These are the different endpoints and each have a cuaU0.* number assigned,


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## balanga (Mar 18, 2018)

```
ATI                                                                                                 
Manufacturer: huawei                                                                                 
Model: K3520                                                                                         
Revision: 11.314.12.02.00                                                                           
IMEI: 353284022975539                                                                               
+GCAP: +CGSM,+DS,+ES                                                                                 
                                                                                                    
OK                                                                                                   
                                                                                                    
^BOOT:22975539,0,0,0,72                                                                             
AT!UDUSBCOMP=?                                                                                       
COMMAND NOT SUPPORT

^BOOT:22975539,0,0,0,72

^BOOT:22975539,0,0,0,72

^BOOT:22975539,0,0,0,72
```

This is using `minicom` on OpenWrt (/dev/ttyUSB2)


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## jef (May 25, 2018)

If this is still an issue, you might want to consider posting on the OpenWRT / LEDE forums at https://forum.lede-project.org/

While I'm not familiar with the specific Huawei part (looks like it may be a "Vodaphone" branded E169 from a quick search), the support for many wireless modems is very good in OpenWRT, simplified even further with the proper LuCI (GUI) plug-in.

The page you referenced looked somewhat outdated. There are slightly different module names now, but my SIM7100A came up in QMI mode, at least for IPv4, without major effort under a developer build of the 18.06 pre-release tree. (This is _not _a recommendation of that specific device.) The usb-modeswitch package is helpful if you have a modem with multiple operating modes.


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