I am currently in Brazil, and my home is based in Germany.
At the moment i have to do a lot of calls, so i wanted to use my VoIP phone through my VPN connection to my home location.
Here in Brazil i have a simple OpenWrt router, providing DHCP on LAN, and providing a VPN connection to the remote location. At the remote location, i have set up an OpenWrt VM, providing direct connection to the SIP gateway (Which is also WAN), and the Wireguard interface on the LAN side.
SIP packets "seem" to flow correctly, but somehow i only have audio in one direction. I cannot hear anything, but the other side can hear me.
Prior to the OpenWrt endpoint i've tried setting up a simple Linux VM, but didn't manage to get any further as in the OpenWrt approach with iptables.
Maybe someone can help me to troubleshoot this SIP seems to be a beast!
chairman@fedora:~$ traceroute 192.168.178.1
traceroute to 192.168.178.1 (192.168.178.1), 30 hops max, 60 byte packets
1 _gateway (192.168.163.1) 0.491 ms 0.426 ms 0.455 ms
2 172.30.30.1 (172.30.30.1) 251.470 ms 251.386 ms 265.839 ms
3 192.168.178.1 (192.168.178.1) 266.030 ms 265.948 ms 265.929 ms
Well, the issue seems to be somewhere between the SIP gateway, and the VoIP device. Directly connected it works, with 2 OpenWrt routers and the Wireguard connection it only does one-way. So it has something to do with OpenWrt. So i'm trying out to figure out, what exactly doesn't work here. I'm suspecting some issue with NAT traversal, and connection tracking.
You've verified that you can initiate connections from Brazil to Germany - what about the other way round? Can your SIP gateway reach your SIP phone?
You might be missing a route to the 192.168.163.0/24 net on the SIP gateway (maybe a Fritz!Box? If it's running a recent FRITZ!OS release, you could also terminate the WG connection there and omit the OpenWrt VM).
Exactly, i'm using a Fritz!Box, didn't know about the Wireguard feature before. I've created a Wireguard config there, and didn't know, i can share the same IP for the peer's wg interface, and internal LAN interface. So i don't have to go through NAT at all.
It also works flawlessly, i think i will go for this solution, as my Wireguard peer is only there for the VoIP device itself.
Thanks for this hint as well!