USB connection - RMNET Driver for MR5100 \ Slow RNDIS Speed on Linux machines

[spamcoll]

I have been struggling to get high speed over RNDIS connection on any linux based systems. I used to get good speed with openwrt (CDC-Ether driver) setup but its now also plagued by same issue. At this point, I am not sure if its an issue with this Hotspot Model (MR5100) or something changed with linux kernel within different distros. For example: Ubuntu used to give good speed of around 800mbps but now gives 70mbps max download while connecting the same hotspot to a windows machine gives around 1.2gbps speed. 

This wired issue is puzzling me for long time. I also do own the MR1100 Model and putting the same SIM card into it equally gives good speed on both linux and Windows machines. I feel that the MR5100 is somehow detecting where its connected to and slows down the USB tethering speed. Another issue is slow IP Passthrough speed using MR5100 in any mode (USB or Ethernet port) but MR1100 has no issues. 

So I have 2 questions manily and hoping someone can help. 

1. Why RNDIS speed is slow on linux distros.

2. If there is no workaround to fix RNDIS speed, then anyone know how to use RMNET driver with these hotspots. 

[Zooapk]

Here are some insights and potential solutions to your questions:

1. Why RNDIS speed is slow on Linux distros:

   The discrepancy in speed between Linux and Windows when using RNDIS may be due to several factors, including driver support, kernel settings, or configuration issues. Here are some steps you can take to investigate and potentially improve the RNDIS speed on Linux:

   • Driver and Kernel Support: Ensure that your Linux distribution has proper RNDIS drivers installed. Sometimes, newer hardware may not be fully supported by older Linux kernels, which could result in slower speeds. Consider updating your kernel to the latest version to see if it resolves the issue.

   • USB Port and Cable: Ensure that you are using a high-quality USB cable and connecting to a USB 3.0 port if available. Slower USB ports or damaged cables can limit the speed.

   • Tethering Mode: Check if the MR5100 has different tethering modes (e.g., USB Ethernet or USB Modem mode). Experiment with different modes to see if any of them offer better speeds.

   • Network Manager Configuration: Sometimes, network manager configurations in Linux can affect speed. Ensure that your network settings are optimized for high-speed connections.

   • Testing Different Linux Distros: Try different Linux distributions to see if the issue persists across all of them. It's possible that one distribution might handle RNDIS differently than another.

2. Using RMNET driver with these hotspots:

   RMNET is another network protocol that can be used for USB tethering. To use the RMNET driver with your hotspot, you may need to compile and load the necessary kernel modules or install specific drivers if they are available for your Linux distribution. Here are general steps to consider:

   • Identify RMNET Driver: Check if there is an RMNET driver available for your hotspot model and your Linux distribution.

   • Compile Kernel Modules: If there's no pre-built RMNET driver, you may need to compile it from source. Ensure that you have the necessary development tools and kernel headers installed.

   • Load the Driver: Once you have the RMNET driver compiled, load it into your kernel using the modprobe command.

   • Configure RMNET: After loading the driver, configure your network settings to use the RMNET interface for USB tethering.

Please note that specific instructions for configuring the RMNET driver and troubleshooting RNDIS speed issues may vary depending on your Linux distribution and the availability of drivers. It's advisable to consult your distribution's documentation and community forums for more tailored assistance.

Ultimately, finding a solution to your RNDIS speed issue may require some experimentation and investigation, but with the right driver and configuration, you should be able to improve the speed on Linux.

[spamcoll]

Thanks for looking into my questions and your response. As mentioned above, I have already tried different distros including the older versions of the Linux distros which used to work before.

About RMNET driver, I am not sure where to find driver and how to compile them. I am not sure if the Linux distros already have it by default.

While looking around this community forum, I stumbled upon a topic which mentioned something about AT command to change hotspot operating mode. Wondering if I need to do that?

AT command they mentioned is "AT!USBCOMP"