pub async fn ring(
endpoint: &Handle,
incoming: &Incoming,
status: u16,
reason: &'static str,
enabled: bool,
) -> Result<Ringing>Expand description
Ring: send a provisional response, reliably if RFC 3262 says to.
enabled is local policy for 100rel. A caller that put 100rel in Require and is told no
gets a 420 Bad Extension naming the tag (§3) and this returns an error — refusing plainly
beats accepting and then never numbering anything, which the caller cannot tell from a dead
network.