Hi, I am trying to setup Open WRT for use with cellular modems...
I assume when I first install it, the relevant packages are not installed and I have to install them from the software menu?
I want to use USB modems, in particular Huawei E3272 and some Sierra Wireless modems, like MC 7455, MC7304 etc. Advice on which packages to install, and then how to setup a cellular WWAN interface would be appreciated (or even a link to the right place in the Wiki!)
Thanks!
The starting page in wiki.
Depending on the chipset of the modem you'll need different kernel modules to install. If you don't have issues with space on the device, you can install them all.
I'm using Sierra Wireless EM7455 (identical to MC7455) in QMI mode and it recently started to work very well with snapshots using luci-proto-qmi (you need kmod-usb-net-qmi-wwan installed as well uqmi).
Alternatively you can also set the modem to MBIM mode and use luci-proto-mbim (for that you need kmod-usb-net-cdc-mbim installed as well as umbim).
If you need to access other ports of the modem you also need kmod-usb-serial-qualcomm which will give you access to Hayes AT-command interface, NMEA-0183 (GPS) and diagnostics port (?).
To permanently switch the operating mode of the modem to either QMI or MBIM you need to access the Hayes AT-command interface, e.g. using picocom:
picocom /dev/ttyUSB2
picocom v3.1
...
ATE1
OK
AT!ENTERCND="A710"
OK
AT!USBCOMP?
Config Index: 1
Config Type: 1 (Generic)
Interface bitmask: 0000010D (diag,nmea,modem,rmnet0)
OK
For details see this post:
https://ltehacks.com/viewtopic.php?t=33
If you are the modem in a mobile setup where you may loose signal for longer periods it may be necessary to use luci-proto-networkmanager instead to handle automatic reconnect (but that requires much more flash space).
For stationary setups uqmi works very well.
MC7455+QMI is a reliable choice. In case, you do not need the speed, I recommend Quectels EC25+PPPD.
Sounds like you're trying to replicate the ROOter project...
Re the packages after initial installation, you assume correctly.
Googling "openwrt lte modem" might be a way to find Wiki pages on the modem topic...
Yes, I use ROOter a lot, and am familiar with AT commands.
I would not say replicate - I have been playing with OpenWRT and you support many more routers than ROOter, so I'd like to use some of my modems on OpenWRT rather then pester the ROOter folks for new builds!
Incidentally, I have been using Fibocom modems (L850GL and L860GL) with ROOter, in NCM mode - but I can't see that OpenWRT supports these?
Many thanks for all the useful information...
Cheers, Bill
Sorry, one final question... When I have installed the right packages, with the corresponding modem interface magically appear, or do I need to explicitly create the interface? In ROOter, it's all there for you...
Cheers again...
That's why you're trying to replicate ROOter: that modem interface and the supporting infrastructure for a wide range of modems is the result of their years of effort, leveraging OpenWrt as the base routing platform (including their extensions to LuCI to support the modem infrastructure). Certain types of modem require relatively little effort to support, e.g. Huawei HiLink (aka hostless) modems, but others as you might notice from the ROOter forum require inordinate amounts of effort to make easily usable. Not to mention a stream of new devices with new capabilities (and lousy documentation 
)...
Yes, i have found that post a while ago... Interestingly, I have a MC7455 and I can access all the necessary ports, but I have two EM7455 modems and can't see the ports at all...
On W10 they are both recognised as 'network adaptors' - DW5811e Snapdragon X7LTE devices, but no ports are created so I can't use AT commands. However, using Sierra Skylight (connection manager for Windows) these EM7455 modems connect and work fine in W10. I wonder if they are in QMI mode, but I can't figure how to change them the MBIM mode...
Any thoughts please?
First of all, make sure you have the kmod-usb-serial-qualcomm package installed.
To enable the qcserial USB enpoints on a device with only mbim active you can do this
root@OpenWrt:~# opkg install qmi-utils
...
root@OpenWrt:~# qmi-cli -d /dev/cdc-wdm0 --dms-swi-get-usb-composition
[/dev/cdc-wdm0] Successfully retrieved USB compositions:
USB composition 6: DM, NMEA, AT, QMI
USB composition 8: DM, NMEA, AT, MBIM
[*] USB composition 9: MBIM
root@OpenWrt:~# qmi-cli -d /dev/cdc-wdm0 --dms-swi-set-usb-composition=8
Personally I've bought E3372h-320 which acts like an Ethernet adapter and I don't have to deal with QMI, MBIM, anything.
You only need to
opkg install usb-modeswitch kmod-usb-net-cdc-ether
and assign a new interface (e.g. eth2) to wan. APN can be set using http://192.168.8.1/ if needed.
Unless you need some fancy stuff (manual modem management, SMS access from scripts) I think it's a good solution. I'm not sure about speed differences, for my office work it works fine.
Some models older than E3372h-320 had slower & less friendly web UI. E3372h-320 is quite fine.
Do you have mobile IPv6 with this E3372h-320 soution?