Odin TeleSystems RTP Bridge User manual

Odin TeleSystems Inc.
RTP Bridge
User’s Guide
Doc. No. 1412-1-SAA-1020-1
Rev. 1.9
December 20, 2010
Copyright © Odin TeleSystems Inc, 2010 www.odints.com

RTP Bridge User’s Guide 2(36)
Copyright
© Copyright 2010, Odin TeleSystems, Inc. All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying,
recording or otherwise, without the prior written consent of Odin TeleSystems Inc., 800 East Campbell Road, Suite
334, Richardson, Texas 75081, U. S. A.
Trademarks
Odin TeleSystems, OTX, RTP Bridge, RTP Streamer, Alvis-CSI, Alvis-PBX, Alvis-PCIe, Alvis-ASM, the Odin
Logo, are trademarks of Odin TeleSystems Inc., which may be registered in some jurisdictions. Other trademarks
are the property of their respective companies.
Changes
The material in this document is for information only and is subject to change without notice. While reasonable
efforts have been made in the preparation of this document to assure its accuracy, Odin TeleSystems Inc., assumes
no liability resulting from errors or omissions in this document, or from the use of the information contained herein.
Odin TeleSystems Inc. reserves the right to make changes in the product design without reservation and notification
to its users.
Warranties
THE PRODUCT AND ITS DOCUMENTATION ARE PROVIDED “AS IS” AND WITHOUT WARRANTY OF
ANY KIND. ODIN TELESYSTEMS EXPRESSLY DISCLAIMS ALL THE WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING, BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR PARTICULAR PURPOSE. ODIN TELESYSTEMS DOES NOT WARRANT THAT THE
FUNCTIONALITY OF THE PRODUCT WILL MEET ANY REQUIREMENTS, OR THAT THE OPERATIONS
OF THE PRODUCT WILL BE UNINTERRUPTED OR ERROR-FREE, OR THAT DEFECTS WILL BE
CORRECTED. FURTHERMORE, ODIN TELESYSTEMS DOES NOT WARRANT OR MAKE ANY
REPRESENTATIONS REGARDING THE USE OF THE PRODUCT OR ITS DOCUMENTATION IN TERMS
OF THEIR CORRECTNESS, ACCURACY, RELIABILITY, OR OTHERWISE. NO ORAL OR WRITTEN
INFORMATION OR ADVISE GIVEN BY ODIN TELESYSTEMS OR ODIN TELESYSTEMS’ AUTHORIZED
REPRESENTATIVE SHALL CREATE A WARRANTY. SOME JURISDICTIONS DO NOT ALLOW THE
EXCLUSION OF IMPLIED WARRANTIES, SO THE ABOVE EXCLUSION MAY NOT APPLY.
UNDER NO CIRCUMSTANCE SHALL ODIN TELESYSTEMS INC., ITS OFFICERS, EMPLOYEES, OR
AGENTS BE LIABLE FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES (INCLUDING
DAMAGES FOR LOSS OF BUSINESS, PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS
INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THE PRODUCT AND ITS DOCU-
MENTATION, EVEN IF ODIN TELESYSTEMS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES. IN NO EVENT WILL ODIN TELESYSTEMS’ LIABILITY FOR ANY REASON EXCEED THE
ACTUAL PRICE PAID FOR THE PRODUCT AND ITS DOCUMENTATION. SOME JURISDICTIONS DO
NOT ALLOW THE LIMITATION OR EXCLUSION OF LIABILITY FOR INCIDENTAL AND CONSE-
QUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR EXCLUSION MAY NOT APPLY.
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 3(36)
Table of Contents
1Introduction.........................................................................................................................................4
1.1 Description ......................................................................................................................................... 4
1.2 Features .............................................................................................................................................. 5
2T1/E1 Channels Configuration..........................................................................................................6
3The RTP Bridge Installation and Running.......................................................................................9
4Command Line Arguments..............................................................................................................10
5The RTP Bridge Commands............................................................................................................11
5.1 Running RTP Bridge Commands from a Configuration File........................................................... 18
5.2 Running RTP Bridge Commands from a Command Line................................................................ 18
5.3 Running RTP Bridge Commands via Telnet Interface..................................................................... 18
6Transcoding Operation.....................................................................................................................19
7Multi-conferences support................................................................................................................22
8Testing Verification Procedure........................................................................................................25
8.1 Testing Scheme 1 ............................................................................................................................. 25
8.2 Testing Scheme 2 ............................................................................................................................. 26
9The RTP Bridge License...................................................................................................................29
10 References .......................................................................................................................................30
11 Product Versions History...............................................................................................................31
12 Document History...........................................................................................................................34
13 Glossary...........................................................................................................................................36
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 4(36)
1Introduction
The RTP Bridge is a universal streaming media gateway application running on the top of
TDM (E1/T1) and RTP media streams designed for the industry's award-winning Odin
Telecom frameworX (OTX) hardware. This document provides detailed information
about the RTP Bridge product.
1.1 Description
The RTP Bridge solution provides data transfer between various E1/T1 timeslots and
RTP end-points in simplex or duplex directions. Voice data could be additionally
transcoded between each of G.711 (a-law, u-law) / G.711.1 / G.711.2 E1/T1 timeslots
and RTP end-points (G.711, G.723, G.726, G.729, GSM-FR, G.722 / G.722.1 / G.722.2
(AMR-WB)) in any order. (See Figure 1)
It is also possible to use the RTP Bridge product without E1/T1 TDM streams. In that
case the RTP Bridge connects data from one IP-Address:Port to another IP-Address:Port,
with transcoding options.
Figure 1 The universal streaming media gateway on the OTX Hardware
The RTP Bridge is targeted to use DaVinci™-enabled products of Odin TeleSystems like
Alvis-CSI, Alvis-PBX, Alvis-PCIe, Alvis-ASM. It runs on the embedded TI DM64XX
SoC processors.
The RTP Bridge uses the OtxRtp Library on the DM6443 SoC ARM core. Also there are
Win32/64 and Linux versions of the OtxRtp Library available.
The RTP Bridge application could be remotely controlled in real-time by the Telnet
interface; it is possible to make connect / disconnect, status monitoring, etc. Connections
could be also taken from the configuration file at startup.
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 5(36)
1.2 Features
Simultaneous bi-directional data transfer between E1/T1 spans and various RTP
remote nodes.
Uses a Telnet interface for E1/T1 timeslot–to-RTP endpoints mapping
configuration.
Transcoding of voice data between any of G.711 (a-law, u-law) / G.711.1 /
G.711.2, G.723, G.726, G.729, GSM-FR, G.722 / G.722.1 / G.722.2 (AMR-WB)
codecs.
Multi-party conferences support. (According to RFC 3550/3551 each RTP
session (listened port) could be connected to some other remote systems. I.e. we
could stream one E1/T1 timeslot to different remote locations at the same time.)
N64 Streaming support (The RTP Bridge allows to send E1 super channels over
UDP to PC, and backwards, to receive UDP packets with E1 data and to send
them to E1 as super channels).
Integrated SNMP monitoring1using the OtxSNMP Library (SNMP Layer1) and
LED Alarms indication.
Possibility to send OTX Events over UDP.
DSP C64+ powered built-in configurable jitter buffer of incoming RTP packets.
TDM Passive monitoring provides the ability to stream E1/T1 spans to the RTP
end-points in a non-intrusive mode.
Optimized data processing using multi-core DaVinci™ architecture with
offloading of all real-time operations on the powerful C64+ DSP core.
Compatible with the OTX DaVinci driver.
Compatible with the OTX XDM SDK API.
Multi-session mode; the user can create any numbers of listening ports on one
system.
Real-time statistics for RTP sessions is available.
Customizable RTP streams parameters: packetizing time, packet size, adjustable
codec parameters, etc.)
Optimized RTP monitoring mode allows to listen RTP streams coming with
different IP-addresses and ports.
Supports IETF RFC 3550, RFC 3551 RTP/RTCP Transport protocols.
A variety of optional decoding / encoding Plugins are available (ATM/AAL5,
HDLC/SS7, TRAU, H.324M).
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
1For more detailed information on SNMP monitoring settings please refer to Alvis-CSI Technical
Description (version 1.5 and later), chapter 8.
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 6(36)
2T1/E1 Channels Configuration
The T1/E1 channels configuration before running the RTP Bridge is optional. It is set in
“OtxHwLayer.conf” file in a case of RTP Bridge uses T1/E1 streams.
The structure of the OtxHwLayer configuration file should be composed from the
parameters provided by line. Each parameter is initialized with the name and the value
represented on a single line through any number of spaces.
Example: T1E1LiMode E1
The configuration file can also contain comments. The comment line begins with ‘#’
character and ends with the end of line. If you need to allocate a few lines for comment,
you should put a ‘#’ character at the beginning of each line.
Example: # Line termination mode
Most of the parameters are set by default; all you need is to define a number of key
parameters: the type of board (BoardType), the index of board (BoardNo), etc.
Please see the full list of configuration file parameters in Table 1.
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 7(36)
Parameter Name Possible Values
Termination OTX_T1E1_TERM_120_OHM,
OTX_T1E1_TERM_100_OHM,
OTX_T1E1_TERM_75_OHM,
OTX_T1E1_TERM_75_OHM_BALANCED,
OTX_T1E1_TERM_300_OHM,
OTX_T1E1_TERM_HIGHZ2
RxThreshold Positive integer, defaults to
OTX_HWLAYER_DEFAULT_RX_THRESHOLD: 500
SetMonitorMode Boolean value P_BOOL3: NO
FrontEndAmplifier Boolean value P_BOOL: OFF
BoardType A2, A2P, A4, A8, A4M, A8M, AA4
BoardNo The index of board, defaults to 0
T1FrameFormat OTX_T1_FF_F12, OTX_T1_FF_F4,
OTX_T1_FF_ESF, OTX_T1_FF_F72,
OTX_T1_FF_F12_J1, OTX_T1_FF_F4_J1,
OTX_T1_FF_ESF_J1, OTX_T1_FF_F72_J1,
OTX_T1_FF_UNFRAMED
T1LineCode OTX_T1_LC_AMI, OTX_T1_LC_B8ZS
E1FrameFormat OTX_E1_FF_DOUBLE_FRAME,
OTX_E1_FF_CRC4_MULTIFRAME,
OTX_E1_FF_CRC4_MULTIFRAME_G706,
OTX_E1_FF_UNFRAMED
E1LineCode OTX_E1_LC_AMI, OTX_E1_LC_HDB3
T1E1LiMode T1, E1
Table 1 The full list of OtxHwLayer configuration file parameters
Note: The default values are marked bold.
2Line termination mode can be one of the following:
OTX_T1E1_TERM_120_OHM – Span is terminated for 120 ohm twisted pair (balanced
differential signal)
OTX_T1E1_TERM_100_OHM – Span is terminated for 100 ohm twisted pair (balanced
differential signal)
OTX_T1E1_TERM_75_OHM –Span is terminated for 75 ohm coax (unbalanced unipolar
signal)
OTX_T1E1_TERM_HIGHZ – Span is not terminated (Balanced, High impedance, for
monitoring scenarios when short (<2 meters) monitor taps are used)
OTX_T1E1_TERM_75_OHM_BALANCED – Span is terminated for 75 ohm balanced
differential signal (for special monitoring conditions)
OTX_T1E1_TERM_300_OHM – Span is terminated for 300 ohm twisted pair (balanced
differential signal)
3Possible values for P_BOOL: TRUE,T,1,YES,ON, FALSE,F,0,NO,OFF.
4Explanation of abbreviations for the BoardType parameter:
A2 - OTX_DEVICE_DMP_ALVIS_2_CSI,
A2P - OTX_DEVICE_DMP_ALVIS_2_PBX,
A4 - OTX_DEVICE_DMP_ALVIS_4_CSI,
A8 - OTX_DEVICE_DMP_ALVIS_8_CSI,
A4M - OTX_DEVICE_DMP_ALVIS_4M_CSI,
A8M - OTX_DEVICE_DMP_ALVIS_8M_CSI,
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
AA - OTX_DEVICE_DMP_ALVIS.
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 8(36)
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010
Example (Alvis-4-CSI):
--------------------------------------------- OtxHwLayer.conf --------------------------------------
E1FrameFormat OTX_E1_FF_CRC4_MULTIFRAME
# Line termination mode
Termination OTX_T1E1_TERM_100_OHM
# Receive threshold (in mV)
RxThreshold 500
# Set Monitor (-20dB) mode (YES/NO)
SetMonitorMode NO
# Turning front end Amplifier ON/OFF
FrontEndAmplifier OFF
T1E1LiMode E1
# Board type
BoardType A4
# Board No
BoardNo 0
-------------------------------------------------- EOF --------------------------------------------------

RTP Bridge User’s Guide 9(36)
3The RTP Bridge Installation and Running
It is recommended to install the RTP Bridge on Alvis-4-CSI board with firmware
package version 2.11.12 or later. For more information of firmware upgrade, please refer
to Alvis-CSI Firmware Upgrade HOW TO (Odin document #1712-1-HCA-1020-1.0-
1.1).
To install the OTX RTP Bridge from rpm repository please follow these steps:
1. Update the rpm repository packets list:
apt-get update
2. Install RTP Bridge package with a command:
apt-get install rtpbridge
3. Reboot the board (Alvis-CSI):
sync & reboot
The RTP Bridge will automatically start at system start-up (daemon mode). You can
connect it via Telnet. If you want to start with CLI, then issue the commands:
service rtpbridge stop
/opt/rtpbridge/rtpbridge
If you will get a “No license found” message please follow the instructions in Chapter 9-
The RTP Bridge License.
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 10(36)
4Command Line Arguments
The RTP Bridge accepts several command line arguments:
--help or -h
Displays help with command line arguments available.
--daemon or -d
Runs the RTP Bridge in a daemon mode.
--pid <file_name> or -p <file_name>
Changes the name of pid-file (where process identifier is stored). By default it is
‘/var/run/rtpbridge.pid’.
--port or -P
Changes port for Telnet interface. By default it is 10000.
--burst or -b
Uses Burst events instead of Core-to-Core mechanism.
--packetsize <msec> or -s <msec>
Sets the default size of RTP packets (in milliseconds) in TDM->RTP Mode.
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 11(36)
5The RTP Bridge Commands
There are several commands available to control / get status of connections between the
RTP and TDM media streams (or mixed):
CONNECT
MCONNECT
LIST
DISCONNECT
DSP LOAD
DSP LOAD EX
BURST STATS
CONSTAT
JITTER BLOCKSJITTER BLOCKS
READCONFIG
SHOW LICENSE
PACKET SIZE
BENCH
TRACES
EVENTS
CONSOLE
CORE
Please see the detailed commands description below.
CONNECT <src_type>:<src_stream>:<src_idx>:[opt]
<dst_type>:<dst_stream>:<dst_idx>:[opt]
This command establish a simplex cross-connect between an incoming and outgoing
stream. To do a duplex connection, one more connection needs to be done separately.
The fields are:
src_type, dst_type:
RTP (RTP connection), TDM (TDM cross-connect), TDMOE (Pseudowire cross-
connect)
src_stream, dst_stream:
For RTP: IP-address, for TDM: Span number
src_idx, dst_idx:
For RTP: Port number (local/remote), for TDM: Timeslot
opt:
Usually src_codec, dst_codec are voice codec used for the specified stream end, e.g.
alaw (or g711a), ulaw (or g711u), g729, g723, g726, etc.
Note:
If src_codec and dst_codec parameters are not specified, they take the default value.
Currently the default codec is alaw.
For the incoming RTP data src_codec can be overridden by the payload type of RTP
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 12(36)
packet.
The abbreviations are: src is source, dst - destination, li - span, ts – timeslot, codec -
codec name, ip – IP-address, r_port – remote port number, l_port – local port number.
For span and timeslot parameters several formats are supported; you can skip li, ts
abbreviations and specify only span and timeslot numbers.
E.g.: li0:ts5 or 0:5.
Below there are several examples of the CONNECT command with some description:
1. TDM -> TDM Mode
connect tdm:<src_li#>:<src_ts#>[:src_codec] tdm: <dst_li#>:<dst_ts#>[:dst_codec]
Example: connect tdm:li0:ts5:ulaw tdm:li1:ts10:alaw
Note: src_codec and dst_codec will be used as a default TDM codec type specified in the
default configuration settings.
2. RTP -> TDM Mode
connect rtp:<src_ip>:<src_remote_port>:<src_local_port>[:src_codec] tdm:
<dst_li#>:<dst_ts#>[:dst_codec]
Example: connect rtp:192.168.102.70:5060:6060:g729 tdm:li0:ts10:alaw
Note: Omitted src_codec will be set according to the incoming RTP payload type
automatically. Omitted dst_codec will be substituted by the default RTP stream encoder
codec.
3. TDM -> RTP Mode
connect tdm:<src_li#>:<src_ts#>[:src_codec]
rtp:<dst_ip>:<dst_remote_port>:<dst_local_port>[:dst_codec]
Example: connect tdm:li0:ts10:alaw rtp:192.168.102.70:5060:6060:g729
4. RTP -> RTP Mode
connect rtp:<src_ip>:<src_remote_port>:<src_local_port>[:src_codec]
rtp:<dst_ip>:<dst_remote_port>:<dst_local_port>[:dst_codec]
Example: connect rtp:192.168.102.60:5060:6060:g726
rtp:192.168.102.70:5060:6060:g729
5. N64 Streaming
connect tdmli:<src_li#>[:format] tdmop:<dst_ip>:<dst_remote_port>:<dst_local_port>
connect tdmop:<src_ip>:<src_remote_port>:<src_local_port> tdmli:<dst_li#>
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 13(36)
The abbreviations are:
src_li, dst_li: source/destination E1/T1 span
src_ip, dst_ip: source/destination IP-address
src_remote_port, dst_remote_port: source/destination
src_local_port, dst_local_port: source/destination local port number
format - defines which timeslots to send/receive; can take following values:
number from 1 to 32 (32 connects 0-31 timeslots, 31 connects 1-31 timeslots, 30
connects 2-31 timeslots, etc)
string ‘raw’ (connects 0-31 timeslots)
mask [ts1,ts2,ts3,…] (defines the list of timeslots to connect)
Example: connect tdmli:0:mask[3,7,11] tdmop:192.168.102.60:5060:6060
Note: If format is not declared, timeslots 1-31 are connected.
Note: With the Alvis-PCIe board you can use only RTP -> RTP connection mode.
Also you can use the connection command with a conference mode. For more
information see chapter 7 Multi-conferences support.
To quickly create many RTP connections please use the following command:
MCONNECT <num_of_conn>
rtp:<src_ip>:<src_remote_port+shift>:<src_local_port+shift>:[src_codec]
rtp:<dst_ip>:<dst_remote_port+shift>:<dst_local_port+shift>:[dst_codec]
The abbreviations are:
num_of_conn: number of connections
src_ip, dst_ip: source/destination IP-address
src_remote_port, dst_remote_port: source/destination remote port number
src_local_port, dst_local_port: source/destination local port number
shift: port’s shift
src_codec: source/destination voice codec used for the specified stream end, e.g. alaw (or
g711a), ulaw (or g711u), g723, g726, g729.
Note:
You can use this command only in the case of RTP Bridge commands run from a
configuration file (Refer to Chapter 5.1).
If src_codec and dst_codec parameters are not specified, they take the default value.
Currently the default codec is alaw.
For the incoming RTP data src_codec can be overridden by the payload type of RTP
packet.
Example: mconnect 31 rtp:192.168.102.90:8002+4:7002+4:alaw
rtp:192.168.102.90:8002+4:9006+4:g729
(Creates 31 connections, See Figure 1Figure 2)
To see the list of existing connections use the command (See Figure 2):
LIST
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 14(36)
Figure 2 List of RTP connections created using mconnect command
To disconnect a certain connection please see the number of this connection in the list
and type the command (See Figure 3):
DISCONNECT <connection_number>
Also for disconnection you can use a command similar to CONNECT:
DISCONNECT <src_type>:<src_stream>:<src_idx>:[opt]
dst_type>:<dst_stream>:<dst_idx>:[opt]
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 15(36)
Figure 3 List of connections after disconnection of one stream
To test the DSP core load you can use the following commands (See Figure 4):
DSP LOAD
Output the DSP load once.
DSP LOAD EX
Output the DSP load in a loop.
Figure 4 DSP core load output
Note: These DSP LOAD commands are available only from console.
To display the Burst statistics use the following command (See Figure 5):
BURST STATS
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 16(36)
Figure 5 Burst statistics output
Note: This command can be run only from console. This command is deprecated. It is
applicable in non Core-2-Core mode of RTP Bridge only.
To display channel statistics (is channel incoming or outgoing, TDM or RTP, payload
type, Jitter statistics for RTP connections) use the command (See Figure 6):
CONSTAT <connection_number>
Figure 6 RTP connection statistics
To set the jitter blocks parameters (size and delay) use the following command:
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 17(36)
JITTER BLOCKS:<max>:<min>
The abbreviations are: max - jitter size, min - jitter delay in 10ms blocks.
Note: New jitter blocks values do not apply to previously created connects. Thus you
should create connects only after jitter blocks command input. This command can not be
run from a configuration file.
Example: jitter blocks:500:30
(jitter time is 5 seconds, jitter delay is 300 milliseconds)
SHOW LICENSE – displays information on RTP Bridge license (customer name,
software version, board serial number, and expiration date).
PACKET SIZE <msec> - sets the default size of RTP packets (in milliseconds) in
TDM->RTP Mode.
Note: This command is only applicable if no connection exists.
BENCH <codec> enc|dec [test_num] - executes codec benchmark.
The abbreviations are:
codec: codec name (e.g. g723)
enc|dec: choose one option to test (encoder or decoder)
test_num - number of tests to run
Note: This command is not applicable to alaw, ulaw and for some decoders. Command is
available only from console. This command is only applicable if no connection exists.
TRACES on|off - switches DSP traces (on/off).
Note: This command can be executed from consolуonly.
EVENTS udp:<dst_ip>:<dst_port>:[<src_port>] - sets up event sending over UDP.
The abbreviations are:
dst_ip: destination IP-address
src_port, dst_port: source/destination port number to send UDP packets
Note:src_port = dst_port by default. This command can be executed from consolуonly.
CONSOLE <cmd> - executes console command.
Note: This command can be executed from configuration file or Telnet interface only.
Example: console traces on
(executes traces on command in console)
CORE <cmd> - executes Telnet interface command.
Note: This command can be executed from consolуonly.
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 18(36)
Example: core readconfig my.conf
5.1 Running RTP Bridge Commands from a Configuration File
To run the RTP Bridge commands from a configuration file please input appropriate
commands in a ‘cfg’ file and place it in a /root directory. The commands will run at RTP
Bridge start-up.
Also to read the commands from the configuration file you can type in Telnet:
READCONFIG <file_name>
5.2 Running RTP Bridge Commands from a Command Line
The RTP Bridge commands can be run from a command line (CLI). Type the appropriate
commands after running of RTP Bridge.
5.3 Running RTP Bridge Commands via Telnet Interface
If the RTP Bridge is already running, you can use the Telnet Interface for dynamic
configuration (real-time control commands). The default port is 10000.
You can restrict access to RTP Bridge via the Telnet interface using White List feature.
For this please create ‘allow.conf’ file in /opt/rtpbridge directory at Alvis board. Specify
the list of allowed IP addresses there. If this file is empty, no one address is allowed. If
‘allow.conf’ does not exist, any IP address has permission to connect to the RTP Bridge.
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010

RTP Bridge User’s Guide 19(36)
Doc. No. 1412-1-SAA-1020-1 www.odints.com Rev. 1.9
Copyright © Odin TeleSystems Inc., 2010
6Transcoding Operation
Odin provides boards with pre-installed and pre-configured vocoders. They are also
available with the OTX XDM SDK.
The RTP Bridge supports the transcoding operation (data converting from one codec to
another as softswitch) by the following scheme:
CodecA -> linear PCM16 -> CodecB.
The RTP Bridge allows to implement transcoding operation of the following codecs:
G.711 (a-law, u-law) / G.711.1 / G.711.2
G.723
G.726
G.729
GSM-FR
G.722 / G.722.1 / G.722.2 (AMR-WB).
Note that it is possible any combination between these codecs as in RTP channels so in
TDM channels.
The transcoding operations are offloaded to powerful C64+ DSP core (4700 MIPS) of the
TI DM64XX SoC processors without increasing the load of ARM core. So the total
number of transcoding channels can be determined by resource-intensiveness of encoding
/ decoding algorithms in accordance with the selected pair of codecs. Below are the
benchmark results to judge the availability and number of channels and CPU. (See Table
2, Table 3)

Codec
name Enc / Dec Number
of test
iterations Bytes processed Milliseconds Bytes output N5
G.723 enc 350 11256000 7270 562800 97
G.723 dec 500 20040000 2657 40080000 943
G.726 enc 120 3859200 6099 964800 40
G.726 dec 60 1200000 7191 4800000 42
G.729 enc 350 11256000 6047 703500 117
G.729 dec 850 4250000 7220 68000000 588
Copyright © Odin TeleSystems Inc, 2010 www.odints.com
Table 2 Synthetic testing results of encoding / decoding operations
Codec
name Enc / Dec Number of connections DSP Load %DSP Load per channel ARM Load % ARM Load per channel
G.711 - 30 10 1.63 28-30 1.9
G.723 enc 35 57 0.43 65-70 1.37
G.723 dec 35 15 3.2 45-50 2.0
G.726 enc 20 64 2.55 38-40 2.15
G.726 dec 20 51 1.53 40-45 1.73
G.729 enc 30 46 0.73 52 1.6
G.729 dec 30 22 0.53 50-55 2.43
Table 3 Overall testing results with account of incoming and outgoing RTP connections and jitter6
The Alvis powered by the RTP Bridge can successfully offload x86 servers increasing
the compactness of solution. This makes possible to create low power-consumption
devices as a breeze. (See Table 4)
Codec
name
Number of
encoding
channels
Number of
decoding
channels
G.723 63 318
G.726 32 39
G.729 63 188
Table 4 Number of encoding / decoding channels
5The number of voice channels that can handle the codec.
6The testing was performed with 20ms RTP packets stream.