Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 77491)
+++ channels/chan_sip.c	(working copy)
@@ -13695,6 +13695,8 @@
 			if (option_debug > 1)
 				ast_log(LOG_DEBUG, "%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;