diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index af27a912e4c1c7a27b52c93753912a3399ad1fa5..4770c9cee25fe63a211f3c5398ea4307582764e6 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -14720,6 +14720,8 @@ static int handle_request_invite(struct sip_pvt *p, struct sip_request *req, int
 		case AST_STATE_UP:
 			ast_debug(2, "%s: This call is UP.... \n", c->name);
 
+			transmit_response(p, "100 Trying", req);
+
 			if (p->t38.state == T38_PEER_REINVITE) {
 				struct ast_channel *bridgepeer = NULL;
 				struct sip_pvt *bridgepvt = NULL;