Description: This patch ensures that when session timer expires in T38 call, Asterisk sends a T38 REINVITE instead of audio reinvite.
Author: Nitesh Bansal <nbansal@voxbone.com>
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -28950,7 +28950,14 @@
 
 	if (p->stimer->st_ref == SESSION_TIMER_REFRESHER_US) {
 		res = 1;
-		transmit_reinvite_with_sdp(p, FALSE, TRUE);
+		if (T38_ENABLED == p->t38.state)
+		{
+			transmit_reinvite_with_sdp(p, TRUE, TRUE);
+		}
+		else
+		{
+			transmit_reinvite_with_sdp(p, FALSE, TRUE);
+		}
 	} else {
 		p->stimer->st_expirys++;
 		if (p->stimer->st_expirys >= 2) {