Did you have interface setup as DHCP client ? and put it to wan firewall group?
config interface 'wwan'
option proto 'dhcp'
option auto '0'
option ifname 'wwan0'
It shouldn't matter which serial port you use to send commands. How do you see that you got an IP? If you got an IP and you can't access internet I think the problem may be something else.
This is probably normal. My modem does exactly the same. But /dev/cdc-wdm0 appear instead and you should be able to use MBIM (in theory... I did not try myself but this one person who made a bug report apparently is using it like that.. so I assume it works.)
Well it actually looks like you got things working both with dhcp client and NCM. I am not sure about whats up with MBIM. I do not use it myself right now but I could try it. By the way, if you setup NCM interface with luci using /dev/ttyUSBX (so without changing bConfigurationValue) it automatically sends the NDISDUP command. When it receives an IP it creates wwan_4. That means you are connected. It is as simple as that
BTW did you setup NCM with a /dev/ttyUSBX port? or did you use /dev/cdc-wdm0 after changing bConfigurationValue?
Anyway, your problem is probably something else. The question is if you have wwan interface in wan firewall group? It looks like your problem is not related to the modem at this point. Because you are getting an IP which means you are able to communicate with the modem and with your ISP.
I am thinking either your WWAN interface is not in wan firewall group (if it is not NAT will not function, you won't be able to access internet) or you do not have NAT setup properly. I think NAT comes setup out of the box so I am guessing you forgot to put the interface to wan group in it's firewall settings?
Bingo! - It's working. Can't thank you enough. I had my head buried in all of this and missed that step in the setup!
So I think the combination to get this working was actually fairly simple, it all came down to that repeating error solved by the correct modification of usb-mode.json.
I never actually removed usb-modeswitch but it doesn't look like I need to as the ttyUSB0-4 all appear on boot and NCM now works when pointed at /dev/ttyUSB2 for an interface.
I had thought when I saw an ip that must mean I was connected so was hoping it was something simple.
So I think it was actually succeeding with using NDISDUP AT command to begin with, and then when I started using NCM I was achieving the same thing as you say.
I think I was also succeeding after changing the bCondig from 0 to 3 then using cdc-wdm0 with mbim - I just hadn't put it in the firewall zone! edit - actually not sure about this, not sure if I ever got an i.p. with mbim. Not gonna screw with it now tho!
Once again, thanks for the guiding hand here, I was kicking myself for not just buying a preconfigured router with modem but it's a real pleasure to get it working after all that!
Actually you seem to have bought great hardware. I used to have EC-25 myself and switch to ME909s-120 recently. I have all sorts of stuff like vpn, port forwarding etc. in my box so openwrt was great for me so far.
Now you can go to some of the bug reports I linked earlier and vote them for fixing. So others won't have the same problem
You did not only get it working one way, you got it working 3 different ways and somebody was saying it is black magic to get it working
1- You got the link up manually using AT commands (with cdc-ether)
2- You got the link working with NCM setup. (with cdc-ether)
3- You got it working with MBIM... I tested this also and it is working.
I think if you never had usb-modeswitch, you could directly setup NCM and get over with it
Well hopefully anyone else who has these issues wont have too much trouble finding this thread, as the solution seems fairly simply in the end!
When you say you could use NCM without usb-modeswitch, would one of the other modules have installed the /etc/usb-mode.json file or are you saying it isn't required at all?
Also - do I have to reguster to vote on those bugfixes? I cant see a way to do so.
It would be easy to find the thread for somebody who had a ME909s-120 but if the problem is with a different device then the required changes will be slightly different and confusing for that person.
Even maybe this thread will not appear in search results when that person searches using another brand/model name.
Furthermore, you nearly failed probably because somebody was thinking exactly the same as you. Solution to this problem is somewhere online so no need to fix the issue. All you need to do is to post a message to issue report and vote it up so it gains higher priority.
You were just lucky because I bought ME909s-120 just last week and had to get it working myself. Otherwise you probably would not have solved this problem, and now be buying EC-25 or something else... and I used EC-25 myself and it was even more difficult to configure.
Would you not liked it better if you installed openwrt and could connect to internet without coming to this forum? The issue in original modeswitch was fixed 2 years ago. The solution is known. It should simply be applied to the modeswitch application which is shipped with OpenWRT. To be honest, I am really disappointed with OpenWRT myself that every time I put a 4G/LTE modem, I need to write scripts and debug issues. (and I wrote some of the scripts in the wiki even)
Anyway, usb-modeswitch is totally unnecessary for ME909s-120. You can uninstall it and things will keep working. It may be easier for you to not have it, if you do not need it. As I told before, I am only keeping it myself because I sometimes use external USB sticks etc. and it comes handy to have it there.
By the way, do you know which firmware version is your card?
You can query it using ATI command I think. You would need to use minicom or picocom to be able to read the response easily
Solution to this problem is somewhere online so no need to fix the issue. All you need to do is to post a message to issue report and vote it up so it gains higher priority.