Huawei E3531 and Raspberry Pi 2

Question

I want to connect a Pi 2 to the web using a 3G Dongle (Huawei e3531). But for some reason I can't get it to work. It is a freshly installed Jessie with update & upgrade done. Modeswitch was installed anyway, so I added ppp.

Plugged in the dongle and checked with 'lsusb', which gave me the expected output of:

Bus 001 Device 004: ID 12d1:14dc Huawei Technologies Co., Ltd.

To get the dongle from storage mode to modem mode I created the file '12d1:1f01' in '/etc/usb_modeswitch.d'. After a reboot lsusb now gives me

Bus 001 Device 005: ID 12d1:1001 Huawei Technologies Co., Ltd. E169/E620/E800 HSDPA Modem

Which should be correct for modem mode. I was able to ping google dns server more or less good. Sometimes perfectly fine, sometimes with a huge packet loss. But that's about it. Downloading data or connecting to websites is not possible.

If I check 'dmesg' it gives me:

[    1.707988] dwc_otg 3f980000.usb: new USB bus registered, assigned bus number 1
[    1.738779] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[    1.748227] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[    1.782148] hub 1-0:1.0: USB hub found
[    1.938481] usbhid: USB HID core driver
[    2.225724] usb 1-1: new high-speed USB device number 2 using dwc_otg
[    2.446117] usb 1-1: New USB device found, idVendor=0424, idProduct=9514
[    2.455984] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    2.466887] hub 1-1:1.0: USB hub found
[    2.745779] usb 1-1.1: new high-speed USB device number 3 using dwc_otg
[    2.856202] usb 1-1.1: New USB device found, idVendor=0424, idProduct=ec00
[    2.866292] usb 1-1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[    2.950681] smsc95xx 1-1.1:1.0 eth0: register 'smsc95xx' at usb-3f980000.usb-1.1, smsc95xx USB 2.0 Ethernet, b8:27:eb:31:ac:7d
[    8.025679] usb 1-1.5: new high-speed USB device number 4 using dwc_otg
[    8.126848] usb 1-1.5: New USB device found, idVendor=12d1, idProduct=1f01
[    8.126868] usb 1-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    8.140409] usb-storage 1-1.5:1.0: USB Mass Storage device detected
[    9.068924] usb 1-1.5: USB disconnect, device number 4
[    9.305684] usb 1-1.5: new high-speed USB device number 5 using dwc_otg
[    9.407006] usb 1-1.5: New USB device found, idVendor=12d1, idProduct=1001
[    9.407025] usb 1-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[    9.453255] usbserial: USB Serial support registered for generic
[    9.468652] usbserial: USB Serial support registered for GSM modem (1-port)
[    9.470380] usb 1-1.5: GSM modem (1-port) converter now attached to ttyUSB0
[    9.471114] usb 1-1.5: GSM modem (1-port) converter now attached to ttyUSB1
[    9.471821] usb 1-1.5: GSM modem (1-port) converter now attached to ttyUSB2

'ifconfig' has only 'eth0' and 'l0'. There was a single time between two of the uncountable reboots while testing, where I got a ppp0 with a 134... IP address. But connectivity was the same.

Getting frustrated I tried approaches like this one: https://github.com/EMnify/doc/wiki/How-to-use-a-Huawei-E3531-in-Modem-Mode

But without any success. Does anyone has an idea what I am missing?

EDIT: Just tested the dongle on a Windows 7 and a Windows 10 computer. On both it is not working. Like on the Pi I am able to ping the google DNS servers, but not able to browse any sites in the browser.

EDIT2: Just bought a cheap lebara SIM with a few hundred megabytes of data for testing. No problem at all. Something seems to be wrong between the SIM and the Dongle...

Answer 1

This doesn't solve the problem, but points to a possible cause: what do you see when you type

$ netstat -rn

? I'm having similar performance issues, and it's because the E3531 installs itself as eth0 at 192.168.1.0 (fixed), which collides with my WiFi adaptor, which is wlan0 at 192.168.1.0. So that explains why packets are getting dropped:

pi@raspberrypi:~ $ lsusb
Bus 001 Device 009: ID 12d1:14dc Huawei Technologies Co., Ltd. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

pi@raspberrypi:~ $ netstat -rn
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG        0 0          0 eth0
0.0.0.0         192.168.1.1     0.0.0.0         UG        0 0          0 wlan0
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U         0 0          0 wlan0

I will continue to search the InterWebs to see how others have addressed this.