SIP trunk to cloud VPS

[nanocool7]

Hey everyone,

I’m trying to set up a connection between my local SIP trunk gateway and a cloud-hosted Asterisk PBX, and I’m considering using SoftEther VPN to make that link.

The goal is to have the SIP gateway at my local site communicate with the cloud PBX as if they’re on the same LAN — mainly to avoid NAT headaches and ensure smoother SIP/RTP traffic. I’m hoping a VPN tunnel can help with this.

Here’s what I’ve got:
Asterisk PBX running on a cloud VPS (with a public IP)
Local SIP trunk gateway behind a NAT (no public IP)
I’d like to use SoftEther VPN to create a secure and stable connection between the two

I have a few questions I’m hoping someone can help with:

Is SoftEther VPN a good choice for this kind of setup — especially for handling SIP and RTP traffic?
What’s the best way to configure it for this use case? Should I go for an L2 bridge, or is L3 routing enough?
Do I still need to worry about NAT/firewall rules for SIP, even with the VPN in place?

Any advice, tips, or real-world experience would be super helpful. Just trying to get this working smoothly without relying on SIP ALG or messy port forwarding.

Thanks :-)

[solo]

The goal is to have the SIP gateway at my local site communicate with the cloud PBX as if they’re on the same LAN

This means L2 and SoftEther is perfect for it.