You can follow this tutorial to configure a Huawei router to connect to LimeVPN using L2TP.
You will have to login to your router’s web interface to configure VPN
Please note, that L2TP alone does not encrypt your traffic, it only reroutes you through one of our servers. Please use it at your own risk. This does not apply to L2TP/IPsec.
Go into your router's administration panel.
Open “VPN” in the left-side menu, and expand the L2TP section.
Enter this configuration:
Enable L2TP LAC: Checked
LNS address: a LimeVPN server address. You can find our server addresses here – for example, us4.limevpn.com
Host name: Any name
Tunnel password: Leave empty
Hello Interval (seconds): 60
PPP username: Your LimeVPN username
PPP password: Your LimeVPN password
Connection mode: Auto