Hi Xingxing, On 01/19/2018 10:52 AM, He, Xingxing wrote: I use usb-modeswitch 2.5.0 (http://www.draisberghof.de/usb_modeswitch/usb-modeswitch-2.5.0.tar.bz2). I had to patch usb-modeswitch to support huawei E3372 with firmware 22.X. I have done that before trying MS2131 so I can't tell if it is necessary for this device (or device firmware). Here is the comment I wrote when I have implemented the modification: After some research I found this interesting message on a forum (http://www.draisberghof.de/usb_modeswitch/bb/viewtopic.php?f=4&t=1734): What has been labelled "fall back" message in this thread is not a Huawei official switch message, it just happens to work in some firmwares. 55534243123456780000000000000011062000000101000100000000000000 is the standard switch message while 55534243123456780000000000000011063000000100010000000000000000 is a Huawei official fall back switch msg switching any modern Huawei dongle into 12d1:1001. The first binary message is the message sent by usb-modeswitch to many Huawei devices. I modified usb-modeswitch to send the second binary message instead. Here is what happens when inserting USB key with this modification: [ 174.120901] usb 1-1: new high-speed USB device number 2 using ci_hdrc [ 174.273073] usb 1-1: New USB device found, idVendor=12d1, idProduct=1f01 [ 174.279807] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 174.287016] usb 1-1: Product: HUAWEI_MOBILE [ 174.291237] usb 1-1: Manufacturer: HUAWEI_MOBILE [ 174.295876] usb 1-1: SerialNumber: 0123456789ABCDEF [ 174.340649] usb-storage 1-1:1.0: USB Mass Storage device detected [ 174.348241] scsi host0: usb-storage 1-1:1.0 [ 175.322850] usb 1-1: USB disconnect, device number 2 [ 175.890898] usb 1-1: new high-speed USB device number 3 using ci_hdrc [ 176.049944] usb 1-1: New USB device found, idVendor=12d1, idProduct=155e [ 176.056720] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 176.063911] usb 1-1: Product: HUAWEI_MOBILE [ 176.068104] usb 1-1: Manufacturer: HUAWEI_MOBILE [ 176.119262] option 1-1:1.0: GSM modem (1-port) converter detected [ 176.140098] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0 [ 176.163530] option 1-1:1.1: GSM modem (1-port) converter detected [ 176.188362] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1 [ 176.221032] option 1-1:1.2: GSM modem (1-port) converter detected [ 176.250351] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB2 [ 176.322577] cdc_ncm 1-1:1.3: MAC-Address: 00:1e:10:1f:00:00 [ 176.328169] cdc_ncm 1-1:1.3: setting rx_max = 16384 [ 176.354358] cdc_ncm 1-1:1.3 wwan0: register 'cdc_ncm' at usb-ci_hdrc.0-1, Mobile Broadband Network Device, 00:1e:10:1f:00:00 A USB device 12d1:155e appears, creates 3 USB serial channels and a cdc_ncm interface. End of comment When I insert an MS2131, here is what I see on my system: [  178.452861] usb 1-1: new high-speed USB device number 2 using ci_hdrc [  178.604840] usb 1-1: New USB device found, idVendor=12d1, idProduct=14fe [  178.611574] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [  178.618782] usb 1-1: Product: HUAWEI Mobile [  178.622991] usb 1-1: Manufacturer: HUAWEI [  178.627009] usb 1-1: SerialNumber: FFFFFFFFFFFFFFFF [  178.652141] usb-storage 1-1:1.0: USB Mass Storage device detected [  178.659862] scsi host0: usb-storage 1-1:1.0 [  179.648202] usb 1-1: USB disconnect, device number 2 [  179.952752] usb 1-1: new high-speed USB device number 3 using ci_hdrc [  180.104463] usb 1-1: New USB device found, idVendor=12d1, idProduct=155e [  180.111194] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [  180.118390] usb 1-1: Product: HUAWEI Mobile [  180.122581] usb 1-1: Manufacturer: HUAWEI [  180.184692] option 1-1:1.0: GSM modem (1-port) converter detected [  180.205743] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB0 [  180.225687] option 1-1:1.1: GSM modem (1-port) converter detected [  180.251829] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB1 [  180.275843] option 1-1:1.2: GSM modem (1-port) converter detected [  180.307996] usb 1-1: GSM modem (1-port) converter now attached to ttyUSB2 [  180.351223] cdc_ncm 1-1:1.3: MAC-Address: 00:1e:10:1f:00:00 [  180.388163] cdc_ncm 1-1:1.3 wwan0: register 'cdc_ncm' at usb-ci_hdrc.0-1, Mobile Broadband Network Device, 00:1e:10:1f:00:00 and a lsusb after that: root@klk-wifc-030122:~ # lsusb Bus 001 Device 003: ID 12d1:155e My usbmodeswitch patch is attached to this mail. Hoping this helps, Christophe