Re: SIP with NAT traversal and STUN using NPF

[Martin Husemann <martin%duskware.de@localhost>]

On Mon, Jun 15, 2026 at 06:04:00PM -0400, Greg Troxel wrote:
> So in the end, did the STUN and NAT work as I was describing, and this
> was just having NAT set up correctly, instead of some odd not-right NAT?

I still think NPF is missing the dynamic symmetric UDP mapping option,
but it is not required for my use case (will investigate this closer,
I may be totaly wrong on this, or if not it would be a good feature
to add, but needs better/other testing).

I am not completely sure what caused the strange effects I saw (and
partly still see). Some of them seem timing or sequence related (old
state both in NPF and the VoIP device persisting accross changes).

But now I know I can get it working with plain NAT and will document
the overall setup once it is polished.

We could use more examples in /usr/share/examples/npf/, but this setup
requires other hacks (additional dhcpcd hooks interacting with NPF,
unrelated to the SIP/VoIP part), so maybe a wiki page describing the
overall setup would be usefull. Or extend the NetBSD guide's NPF
chapter.

Martin