Help with MC7455 in OpenWRT router

Yup what he said ^.

I soldered another usb cable to my mini pci-e adapter board (just the black and red) and plugged it into the 3.0 port for more power.

The new reconnect method replaces the watchcat method. Stop the watchcat and do the other method. The loopback is for an xbox or a server or anything. I changed my loopback file to192.168.1.150 and (my router ip is I aim my xbox to this address and port forward for open nats.

I agree it’s not the mbim itself. On the last reconnect method I mentioned the mbim is modified to start and stop watchdog and to restart the reconnect scripts so you don’t have multiple things going on.

The final mbim runs all the reconnect stuff.


I test MC7455 with OpenWrt firmware on our embedded device.
I encounter connection block issue when plug MC7455 into USB3.0 port and start to browse Youtube or send/receive some stream.
And MC7455 still connected on BS when the connection blocking.
The issue is gone once I change to plug MC7455 into USB2.0 port.

I see westrem’s instruction specify that plug MC7455 into USB2.0 as below.
plug the modem into the 2.0 usb port. Not the 3.0 port.

Could anyone tell me why can not plug MC7455 into USB2.0?
Is there any known issue for MC7455 to support USB3.0 although Product Technical Specification specify MC7455 support USB2.0 and USB3.0?
If I must to plug MC7455 into USB3.0, any thing I can do to address this issue?



I’m also wondering if there are problems using USB2.0 versus USB3.0 interfaces?

From what I have heard it’s a power issue on the 3.0 port or an issue of power being toggled on the 3.0 port with the mc7455 on it. That’s all I have heard and know.

When using ModemManager in OpenWRT, you don’t even need to switch the device to MBIM mode (although you can do it if you want to). The same settings would work for the MC7455 in MBIM mode or in QMI mode. Actually, the same exact settings would also work for other devices as well, see:

Note, though, that if using the MC7455 you will want to have at least kernel 4.5, which is when the raw-ip support in the qmi_wwan driver was included.

This is true. But neither openwrt nor LEDE are using a 4.5 or higher kernel yet so MBIM is the only way to go for now. Unless you build something yourself that is.

ROOter is close to having their openwrt firmware working with the mc7455 chip. Dairyman the creator of modemmanager also makes ROOter.

For now the only way without a lot of rebuilding is using the newest LEDE firmware and mbim mode.

Dairyman didn’t create ModemManager…

Oh I stand corrected then. Sorry I thought he did. I must have misread that somewhere.

I see where I made that mistake. Dairyman created a modem conection manager not modemmanager. Sorry for the misinformation.

Just fyi: aleksander0m makes modemmanager :slight_smile:

(along with a few others of course, but aleksander is the primary developer nowadays)

Yup I realize now. Foot in mouth.

What’s the problem with that way?

No problems at all.

:smiley: No worries


We are using MC7354 in openwrt routers with qmi-wwan and serial option drivers not Gobi driver, we need to update firmware. how to update firmware please tell me.

The simplest way would be to just plug it into the computer and do it from there.

No, actually our devices are in clients locations not in my location so i need to change firmware verizon to ATT or ATT to Verizon like that so i can’t update with that way. we giving to devices customers so whenever they want to convert verizon to ATT we need to provide that firmware

The mc7455 holds up to 4 firmwares I believe. Then to switch firmware all thats needed is at!impref=“whatever firmware you want”

I named mine

I know this doesn’t help you now but I’m not sure how you would do it any other way if you didn’t do it when it was in your possession.

Easy! (at your own risk)

Build libqmi from git master, explicitly using–without-udev during configure.

See qmi-firmware-update --help and --help-examples.

If running in OpenWRT/LEDE you’ll need several manual steps, as listed in the example below. In standard distributions with udev support, see examples for the more advanced “–update” operation.

Example: Manual process to update a Sierra Wireless MC7354.
  (or other 9x15 or 9x30 devices, like the MC7304, MC7330, MC7455... ).

 The upgrade of devices from the 9x15 and 9x30 families is triggered via a
 'firmware preference' setting. If the device accepts the setting, the user
 can request a device power cycle, which will boot in QDL download mode:

 a) Set firmware preference setting:
    $ sudo qmicli \
          -d /dev/cdc-wdm0 \

 b) Request power cycle:
    $ sudo qmicli \
          -d /dev/cdc-wdm0 \
    $ sudo qmicli \
          -d /dev/cdc-wdm0 \

 c) Wait for the /dev/ttyUSB device to appear.

 d) Run updater operation while in QDL download mode:
    $ sudo qmi-firmware-update \
          -t /dev/ttyUSB0 \
          --update-qdl \
          SWI9X15C_05.05.58.00.cwe \

 d) Now wait for the device to fully reboot, may take up to several minutes.
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I’m running my setup using all the instructions that were provided to me via this thread. Everything works great when it is working, however, at least every couple days I lose Internet and it is very difficult to get the router and modem working again. I get all kinds of mbim errors, subscription errors, etc. It never reboots with the correct date and time. But then sometimes the watchdog program fixes it right away, or one reboot fixes it. It’s so frustrating. If I’m not at home when it happens, my wife and teenagers are without Internet until I get home and fix it. I still don’t know why it happens. I don’t know if it’s my hardware, a software error, or the Sprint signal.

With the recent return of Verizon’s unlimited data, I’m considering dumping my unlimited Sprint and adding the modem to my existing Verizon account. My question is, how easy/difficult would it be to convert the Linksys router and MC7455 from Sprint to Verizon?

Also, I was told not to install Sprint specific firmware on the MC7455, or I wouldn’t be able to get it connect,so the discussion above confuses me. What is the point of installing all the different firmwares if they don’t help? I was told the generic firmware would mask my actual hardware from Sprint and prevent them from blocking me. Is this the case with Verizon also? Is anyone using this setup with Verizon?

Thank you all for helping me get this far.