Limit of PPP Connections on Armbian with Multiple USB 3G/4G Dongles

[Eugenio Eugenio]

Hello everyone,

I’ve been working with 25-30 USB 3G/4G dongles successfully on Debian and Ubuntu, where all connections work without issues. However, on Armbian, I can only establish around 10 PPPoE connections.

 

Here are the details of my setup:

• OS: Armbian based on Debian 10 (I also tried updating to Debian 11) - IMG: Sunvell rkship and 
• Kernel Version: linux-image-current-sunxi 24.11.1
• Packages Used: ppp, eject, and usb-modeswitch (tested with the latest versions)
• Logs: /var/log/ppp.log doesn’t show any errors.

Isos: 

• Armbian 21.05.1 stable, kernel 4.4 (SoC Rockchip rk322x)
• Armbian 20 - Debian 10 ARM (SoC Alllwinner H3) - Sunvell R69
  • https://mega.nz/file/4ugAhKjb#NIt6KIv2tsPFzVVGwLcykFSdQp0MgCXgdCzxcj0PUxA
  • https://mega.nz/file/V3QQyBaY#Y332sD2oa36L5BZa0xtANx1O6QrS_903Qj1RHg1vuy8

 

I’ve read that some kernel parameters may limit handling multiple PPP sessions or high network traffic. For example, I came across the parameter net.core.max_skb_frags, which seems relevant but I haven’t made adjustments yet.

Has anyone encountered this issue or know what configurations I can tweak to improve Armbian's capability to handle more PPPoE connections?

Any advice on kernel parameters, USB handling, or PPP configurations would be greatly appreciated.

Thank you!

[Igor]

9 hours ago, Eugenio Eugenio said:

I’ve been working with 25-30 USB 3G/4G dongles successfully on Debian and Ubuntu

 

I assume you achieved this performance on cca. 20 x more expensive Intel based hardware? First lets rule out user space. Try Armbian x86 https://www.armbian.com/uefi-x86/ on that.

 

9 hours ago, Eugenio Eugenio said:

• Armbian 21.05.1 stable, kernel 4.4 (SoC Rockchip rk322x)
• Armbian 20 - Debian 10 ARM (SoC Alllwinner H3) - Sunvell R69

 

None of this was ever officially supported. And those are 3-4 years builds from 3rd party repository. Armbian makes tools for making custom OS and this was made by "someone" from a vendor kernel that is deprecated in years.

 

9 hours ago, Eugenio Eugenio said:

Any advice on kernel parameters

 

I can only give you general advice. 

 

- develop image around modern kernel ( config exists but it might not work https://github.com/armbian/build/blob/main/config/boards/sunvell-r69.tvb and https://github.com/armbian/build/blob/main/config/boards/rk322x-box.tvb)

- use hardware that is capable of achieving this

 

Good luck.