Description:
Receiving a retransmission of an INVITE request while in the "Proceeding" state does not repeat its last response.

However, according to RFC 3261 Section 17.2.1:
"If a request retransmission is received while in the 'Proceeding' state, the most recent provisional response that was received from the TU MUST be passed to the transport layer for retransmission."

Below is the log from eXosip2:

/* use-case: 1/ a duplicate of initial INVITE is received (same TOP Via header) after we replied -> discard */
OSIP_TRACE (osip_trace (_FILE_, _LINE_, OSIP_ERROR, NULL, "eXosip: drop INVITE retransmission after INVITE reply\n"));
How should I respond with a 1XX to the retransmitted INVITE message?

Thank you for your time and consideration. I appreciate any feedback you can provide.