What happens to call on 5G SA if 404, 500 error code received?

5G NR
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1

Hello.

If there is error code 404, 500 for VoNR call, what happens to call on 5G SA?

Is it Fallback or not to LTE?

2

500 codes are server error in SIP.

404 Not Found.
The server has definitive information that the user does not exist at the domain specified in the Request-URI.
This status is also returned if the domain in the Request-URI does not match any of the domains handled by the recipient of the request.

More details here: SIP response status codes

3

Thanks!

So what will UE do?

Will it not retry for call?

I mean not like VoLTE retry for CSFB option with SIP error code.