Issue having huawei E3276 dongle when dongle haiving internet connection that time no send AT commands

Hi ,
i am facing same problem actually i am huawei E3276s modem it gives two port /dev/ttyUSB2 and /dev/ttyUSB3 when i am connecting 3g mode ttyUSB2 not working but at sometime ttyUSB3 work to send msg but it also add some garbage value and sometime skip some msg body content.if you solve this problem please.................................... guide me if you any idea about it please share with me or if any one solve this issue please help me.

Thank you

install usb utils

find the devid's for the relevant nodes.


from there you can blacklist or assign device labels to troubleshoot further.....

Please also explain your full environment... device, firmware version etc. it will help others.

You also have to break this down into CLEAR, SEPARATE SEQUENCES OF EVENTS..... with ACTUAL tests performed..... From what you have written, it is unclear as to what is going on .....

Thank you for valuable response
i explain my issue

  • i have openwrt firmware version 4.14.70 and architecture mips.
  • my company gives me hardware on that board one usb port is there where i am connected huawei 3276 dongle and i already installed usb utils package and my dongle detect as network device.

Bus 001 Device 006: ID 12d1:1506 Huawei Technologies Co., Ltd. Modem/Networkcard

-packages installed on my firmware

-when i typed dmesg it gives output two serial port ttyUSB2 and ttyUSB3 one for data connection and other for AT commands .
-so in my etc/config/network file i define new interface "3g-wwan" so it sucessfully connected to internet 3g and gives ip .but at that time i send sms through dongle using ttyUSB3 it send msg but skip some content from msg body. i want to use both sevices so how to solve that ? please help me

Thank you

Any reason you aren't using?;


no reason actually i am using ppp protocol and installed kmod-usb-serial ,kmod-usb-srial-option.kmod-usb-serial-wwan these package .i am not NCM protocol so i am not install that package kmod-usb-net-huawei-cdc-ncm .
-Is there any advantage to use this NCM protocol ?
please reply

thank you very much