Tayga? local IPv4 forward to public IPv6

I am not sure how to gt this running:
A VoIP (SIP) to analog phone converter called SPA112 is on
The Gateway / Registrar Host:5060 for SIP has an AAAA record only.

frood@ka:~$ host -t AAAA hiq8b-sbcv61a.kabelbw.de
hiq8b-sbcv61a.kabelbw.de has IPv6 address 2a02:908:a:1000::59
frood@ka:~$ host -t A hiq8b-sbcv61a.kabelbw.de
hiq8b-sbcv61a.kabelbw.de has no A record

The SPA112 understands IPv4 only.

Do I need something like NAT64 or a port forward outbound from LAN to WAN with SRC IP proto IPv4 and DEST IP proto IPv6 --> and the way around?

There are also IPv4 Registrars, but it seems as they did assign this IPv6 to me only (because it was also used in the past).

I'd contact the SIP server's administrator. It surprises me that they would only provide IPv6 service.

Without being familiar with kabelbw, but the hostname itself sounds a bit unlikely to be the official DNS name for an ISP's SIP services (it might very well be one of the servers behind it, but unlikely to be the official DNS entry).

Given that kabelbw is pushing dslite, only offering IPv6 for their own services might not be impossible though.

this is kabelbw. Their organization and support processes are totally chaotic, messy and crap.
I have the TC4400 activated, up and running and very happy I made it that far.
There are no admins to contact, I have doubts that there is any chance to get this cleared on their side.

It was just intuitive that I wanted to somehow do a forwarding / setup of a proxy to let the internal ipv4 client talk to the external ipv6 something. I thought that this could be done on OpenWrt since there is stuff like NAT64.

But there are otehr people having bis issues with this task: https://www.unitymediaforum.de/viewtopic.php?f=53&t=33846&p=423028#p423028
And it might be easier just to "change" the number and go for sipgate.

I took a wild guess...

$ host -t A hiq8b-sbcv41a.kabelbw.de
hiq8b-sbcv41a.kabelbw.de has address

searching the net bring up even more than guessing
IPv6: hiq6a-sbcv61a.kabelbw.de
IPv4: hiq6a-sbcv41a.kabelbw.de

but this is not related to the question.

Buy a Grandstream ht802 which has native ipv6, ipv6 is a delight for sip because you have no NAT nastiness.

As an alternative the best method would be a freeswitch or asterisk server. You can't just NAT64 because the sip messages contain IP addresses.

could be an option... yes, especially because of that NAT punch stuff..

but; does it mean that is it not possible to do port forwardings from IPv4 SRC to IPv6 DEST and the way around?

Different protocols, you can't just "forward" one to the other.

Some of the compatibility approaches, such as NAT-PT, have been relegated to the past long ago (2007).

That's right because the content of the messages needs to be changed because the messages communicate connectivity and you are secretly changing the connectivity.

and what about NAT64 - an IPv6 to IPv4 translator e.g. http://blog.raorn.name/2012/02/ipv6-only-lan-with-dual-stack-openwrt.html
On OpenWrt the message / connection could be terminated

NAT64 can make the messages flow but it can't make the messages meaningful it's like if you send me letters in Chinese and someone translates the address for you and puts it in an envelope that American postal service can read, I can get your letters but I can't understand them.

In particular, how do you think your SPA112 will like it when it gets an INVITE message saying to connect back on 2002:2010:aaff:1100::ba2b port 23000 ?