User`s manual
Table Of Contents
- Mediant 2000 & TP-1610 & TP-260/UNI SIP User’s Manual Version 5.0
- Table of Contents
- List of Figures
- List of Tables
- Notices
- 1. Overview
- 2. Physical Description
- 3. Installation
- 4. Getting Started
- 5. Web Management
- Computer Requirements
- Protection and Security Mechanisms
- Accessing the Embedded Web Server
- Getting Acquainted with the Web Interface
- Protocol Management
- Advanced Configuration
- Status & Diagnostic
- Software Update Menu
- Maintenance
- Logging Off the Embedded Web Server
- 6. Gateway's ini File Configuration
- Secured ini File
- Modifying an ini File
- The ini File Content
- The ini File Structure
- The ini File Example
- Networking Parameters
- System Parameters
- Web and Telnet Parameters
- Security Parameters
- RADIUS Parameters
- SNMP Parameters
- SIP Configuration Parameters
- Voice Mail Parameters
- ISDN and CAS Interworking-Related Parameters
- Number Manipulation and Routing Parameters
- E1/T1 Configuration Parameters
- Channel Parameters
- Configuration Files Parameters
- 7. Using BootP / DHCP
- 8. Telephony Capabilities
- Working with Supplementary Services
- Configuring the DTMF Transport Types
- Fax & Modem Transport Modes
- Event Notification using X-Detect Header
- ThroughPacket™
- Dynamic Jitter Buffer Operation
- Configuring the Gateway’s Alternative Routing (based on Conn
- Call Detail Report
- Supported RADIUS Attributes
- Trunk to Trunk Routing Example
- Proxy or Registrar Registration Example
- SIP Call Flow Example
- SIP Authentication Example
- 9. Networking Capabilities
- 10. Advanced PSTN Configuration
- 11. Advanced System Capabilities
- 12. Special Applications
- 13. Security
- 14. Diagnostics
- 15. SNMP-Based Management
- SNMP Standards and Objects
- Carrier Grade Alarm System
- Cold Start Trap
- Third-Party Performance Monitoring Measurements
- TrunkPack-VoP Series Supported MIBs
- Traps
- SNMP Interface Details
- SNMP Manager Backward Compatibility
- Dual Module Interface
- SNMP NAT Traversal
- SNMP Administrative State Control
- AudioCodes’ Element Management System
- 16. Configuration Files
- Appendix A. Selected Technical Specifications
- Appendix B. Supplied SIP Software Kit
- Appendix C. SIP Compliance Tables
- Appendix D. The BootP/TFTP Configuration Utility
- Appendix E. RTP/RTCP Payload Types and Port Allocation
- Appendix F. RTP Control Protocol Extended Reports (RTCP-XR)
- Appendix G. Accessory Programs and Tools
- Appendix H. Release Reason Mapping
- Appendix I. SNMP Traps
- Appendix J. Installation and Configuration of Apache HTTP Server
- Appendix K. Regulatory Information
Mediant 2000 & TP-1610 & TP-260
SIP User's Manual 232 Document #: LTRT-68805
9.3.2 First Incoming Packet Mechanism
If the remote gateway resides behind a NAT device, it’s possible that the gateway can
activate the RTP/RTCP/T.38 streams to an invalid IP address / UDP port. To avoid such
cases, the gateway automatically compares the source address of the incoming
RTP/RTCP/T.38 stream with the IP address and UDP port of the remote gateway. If the
two are not identical, the transmitter modifies the sending address to correspond with the
address of the incoming stream. The RTP, RTCP and T.38 can thus have independent
destination IP addresses and UDP ports.
Users can choose to disable the NAT mechanism by setting the ini file parameter
‘DisableNAT’ to 1. The two parameters ‘EnableIpAddrTranslation’ and
‘EnableUdpPortTranslation’ enable users to specify the type of compare operation that
takes place on the first incoming packet. To compare only the IP address, set
‘EnableIpAddrTranslation = 1’ and ‘EnableUdpPortTranslation = 0’. In this case, if the first
incoming packet arrives with only a difference in the UDP port, the sending addresses
won’t change. If both the IP address and UDP port need to be compared, then both
parameters need to be set to 1.
9.3.3 No-Op Packets
The gateway's No-Op packet support can be used to verify Real-Time Transport Protocol
(RTP) and T.38 connectivity, and to keep NAT bindings and Firewall pinholes open. No-Op
packets are available for sending in RTP and T.38 formats.
Users can control the activation of No-Op packets by using the ini file parameter
NoOperationSendingMode. If No-Op packet transmission is activated, users can control
the time interval in which No-Op packets are sent in the case of silence (i.e., no RTP or
T.38 traffic). This is performed using the NoOpInterval ini parameter.
Note: Receipt of No-Op is always supported.
RTP No-Op:
The RTP No-Op support complies with IETF’s draft-wing-avt-rtp-noop-03.txt (titled ‘A
No-Op Payload Format for RTP’). This IETF document defines a No-Op payload
format for RTP.
The draft defines the RTP payload type as dynamic. Users can control the payload
type with which the No-Op packets are sent. This is performed using the
RTPNoOpPayloadType ini parameter. AudioCodes’ default payload type is 120.
T.38 No-Op:
T.38 No-Op packets are sent only while a T.38 session is activated. Sent packets are
a duplication of the previously sent frame (including duplication of the sequence
number).