doc for transfer

git-svn-id: http://svn.berlios.de/svnroot/repos/sems/trunk@142 8eb893ce-cfd4-0310-b710-fb5ebe64c474

doc/Readme.announce_transfer

@@ -0,0 +1,53 @@
+Announcement then call transfer 
+
+This application plays an announcement and then REFERs the caller
+to either the uri configured in P-Refer-To header, or if his is not
+configured, the request URI of the first INVITE.
+
+If refer is not accepted, succeeds, or fails, a BYE is sent.
+
+Example ser configuration appends:
+
+#appends: parameter for announce_transfer
+modparam( "tm", "tw_append",
+   "announce_transfer_headers:P-Refer-To=avp[$refer_to]")
+
+# appends for REFER NOTIFYs
+modparam( "tm", "tw_append",
+   "notify_headers:hdr[Content-Length];hdr[Content-Type];hdr[Event];msg[body]")
+
+Example of invoking announce_transfer within route:
+
+	if (method != "ACK" && method != "INVITE"  
+		&& method != "CANCEL" && method != "INFO" 
+		&& method != "NOTIFY" && method != "BYE" ){
+			log("unsupported method\n");
+			sl_send_reply("500","unsupported method");
+			break;
+	}
+   
+	if (method == "NOTIFY") {
+		if (!t_write_unix("/tmp/sems_sock","announce_transfer/notify_headers")){
+			log("could not contact announce_transfer\n");
+			t_reply("500","could not contact media server");	
+			break;
+		}
+		break;
+	} 
+
+	if (method == "INVITE") {
+		avp_write("sip:callme@example.com","$refer_to");
+		if (!t_write_unix("/tmp/sems_sock","announce_transfer/announce_transfer_headers")){
+			log("could not contact announce_transfer\n");
+			t_reply("500","could not contact media server");	
+			break;
+		}
+		break;
+	}
+
+	if (!t_write_unix("/tmp/sems_sock","announce_transfer")){
+		log("could not contact announce_transfer\n");
+		t_reply("500","could not contact media server");	
+		break;
+	}
+