Function ring_early_with 

pub async fn ring_early_with(
    endpoint: &Handle,
    incoming: &Incoming,
    status: u16,
    reason: &'static str,
    media_address: IpAddr,
    codecs: Codecs,
) -> Result<Ringing>

ring_early, from a chosen codec set rather than the default one (M-30).

The Call that crate::answer_early builds inherits codecs, so an UPDATE arriving before the 200 — the whole reason this path exists — is answered from the same set the 183 answered from rather than from the default one.