1 files changed, 48 insertions, 0 deletions
diff --git a/openbsc/include/openbsc/mgcp.h b/openbsc/include/openbsc/mgcp.h
new file mode 100644
index 000000000..fa6224c12
--- /dev/null
+++ b/openbsc/include/openbsc/mgcp.h
@@ -0,0 +1,48 @@
+/* A Media Gateway Control Protocol Media Gateway: RFC 3435 */
+
+/*
+ * (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2009 by on-waves.com
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+unsigned int rtp_base_port = 4000;
+
+/**
+ * Calculate the RTP audio port for the given multiplex
+ * and the direction. This allows a semi static endpoint
+ * to port calculation removing the need for the BSC
+ * and the MediaGateway to communicate.
+ *
+ * Port usage explained:
+ *       base + (multiplex * 2) + 0 == local port to wait for network packets
+ *       base + (multiplex * 2) + 1 == local port for rtcp
+ *
+ * The above port will receive packets from the BTS that need
+ * to be patched and forwarded to the network.
+ * The above port will receive packets from the network that
+ * need to be patched and forwarded to the BTS.
+ *
+ * We assume to have a static BTS IP address so we can differentiate
+ * network and BTS.
+ *
+ */
+int rtp_calculate_port(int multiplex, int base)
+{
+	return base + (multiplex * 2);
+}