modules/rtpengine: unset "don't fragment" ip header flag

modules/rtpengine/rtpengine.c

@@ -1438,6 +1438,9 @@ child_init(int rank)
 	struct addrinfo hints, *res;
 	struct rtpp_set  *rtpp_list;
 	struct rtpp_node *pnode;
+#ifdef IP_MTU_DISCOVER
+	int ip_mtu_discover = IP_PMTUDISC_DONT;
+#endif
 
 	if(rtpp_set_list==NULL )
 		return 0;
@@ -1500,6 +1503,12 @@ child_init(int rank)
 				return -1;
 			}
 
+#ifdef IP_MTU_DISCOVER
+			setsockopt(rtpp_socks[pnode->idx], IPPROTO_IP,
+				   IP_MTU_DISCOVER, &ip_mtu_discover,
+				   sizeof(ip_mtu_discover));
+#endif
+
 			if (bind_force_send_ip(pnode->idx) == -1) {
 				LM_ERR("can't bind socket\n");
 				close(rtpp_socks[pnode->idx]);