| Holger Hans Peter Freyther | f67945f | 2009-10-09 07:08:11 +0200 | [diff] [blame] | 1 | /* A Media Gateway Control Protocol Media Gateway: RFC 3435 */ |
| 2 | |
| 3 | /* |
| 4 | * (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org> |
| 5 | * (C) 2009 by on-waves.com |
| 6 | * All Rights Reserved |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License along |
| 19 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 20 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 21 | * |
| 22 | */ |
| 23 | |
| 24 | unsigned int rtp_base_port = 4000; |
| 25 | |
| 26 | /** |
| 27 | * Calculate the RTP audio port for the given multiplex |
| 28 | * and the direction. This allows a semi static endpoint |
| 29 | * to port calculation removing the need for the BSC |
| 30 | * and the MediaGateway to communicate. |
| 31 | * |
| 32 | * Port usage explained: |
| 33 | * base + (multiplex * 2) + 0 == local port to wait for network packets |
| 34 | * base + (multiplex * 2) + 1 == local port for rtcp |
| 35 | * |
| 36 | * The above port will receive packets from the BTS that need |
| 37 | * to be patched and forwarded to the network. |
| 38 | * The above port will receive packets from the network that |
| 39 | * need to be patched and forwarded to the BTS. |
| 40 | * |
| 41 | * We assume to have a static BTS IP address so we can differentiate |
| 42 | * network and BTS. |
| 43 | * |
| 44 | */ |
| 45 | int rtp_calculate_port(int multiplex, int base) |
| 46 | { |
| 47 | return base + (multiplex * 2); |
| 48 | } |