I'm using Huawei E3276 mobile modem for 4G LTE connection with Linux Manjaro XFCE 64bit, works out of the box without driver installs made by user. Problem is that while download is working normally as it should, upload is very slow. While on Windows 7 upload is steady 30-40Mbps depending on day, but on Linux it barely hits 4Mbps.
Could it be a driver problem or a bug as a friend of mine suggested? And is it possible to fix it and how? This is as for now only thing for me that is kind of pulling me back to Windows so would love to get this fixed ASAP.
Edit 1: While other Linux distros have this upstream throttle, on Linux Mint Debian Edition 201403 upload is working as it should, usually being around 30-45Mbps.
The same symptoms seem to be present in different hardware and Linux distributions: also with Ubuntu 14.04 LTS (64 bit workstation, kernel 3.16) and Raspbian Jessie for Raspberry PI (kernel 3.14).
Upstream seems to be always limited to about 5 Mbit/s whenever checking the speed from the Linux computer that is used as an LTE router. The other computers in the LAN always get much more upstream (2 to 3 times as much), even though the traffic is routed through the same Linux computer suffering from seemingly capped uplink.
A Windows 7 installation in the same hardware as Ubuntu does not have this uplink limitation. So the problem is not with E3276 device itself or in the mobile subscription, but in the Huawei E3276 Linux compatibility. Maybe something in the kernel?
It is not a matter with
iptables rules: the speed does not noticeably increase when
iptables is disabled. Turning off IPv4 forwarding does not improve speed either.