P-2302R Series VoIP Station Gateway User's Guide
Table Of Contents
- P-2302R Series
- User’s Guide
- Copyright
- Federal Communications Commission (FCC) Interference Statement
- Safety Warnings
- ZyXEL Limited Warranty
- Customer Support
- Table of Contents
- List of Figures
- List of Tables
- Preface
- Introducing the Prestige
- Introducing the Web Configurator
- Wizard Setup
- System Screens
- LAN Setup
- WAN Screens
- Introduction to VoIP
- VoIP Screens
- Phone
- Phone Book
- Phone Usage
- Network Address Translation (NAT) Screens
- Static Route
- Firewall
- Content Filtering
- Remote Management Screens
- Universal Plug-and-Play (UPnP)
- Logs
- Bandwidth Management
- 19.1 Bandwidth Management Overview
- 19.2 Bandwidth Classes and Filters
- 19.3 Proportional Bandwidth Allocation
- 19.4 Application-based Bandwidth Management
- 19.5 Subnet-based Bandwidth Management
- 19.6 Application and Subnet-based Bandwidth Management
- 19.7 Scheduler
- 19.8 Maximize Bandwidth Usage
- 19.9 Bandwidth Borrowing
- 19.10 Configuring Summary
- 19.11 Configuring Class Setup
- 19.12 Configuring Monitor
- Maintenance
- Introducing the SMT
- General Setup
- WAN Setup
- LAN Setup
- Internet Access
- Remote Node Configuration
- Static Route Setup
- Network Address Translation (NAT)
- Enabling the Firewall
- Filter Configuration
- SNMP Configuration
- System Information and Diagnosis
- Firmware and Configuration File Maintenance
- 33.1 Filename Conventions
- 33.2 Backup Configuration
- 33.2.1 Backup Configuration
- 33.2.2 Using the FTP Command from the Command Line
- 33.2.3 Example of FTP Commands from the Command Line
- 33.2.4 GUI-based FTP Clients
- 33.2.5 TFTP and FTP over WAN Management Limitations
- 33.2.6 Backup Configuration Using TFTP
- 33.2.7 TFTP Command Example
- 33.2.8 GUI-based TFTP Clients
- 33.3 Restore Configuration
- 33.4 Uploading Firmware and Configuration Files
- System Maintenance
- Remote Management
- Call Scheduling
- Troubleshooting
- 37.1 Problems Starting Up the Prestige
- 37.2 Problems with the LAN Interface
- 37.3 Problems with the WAN Interface
- 37.4 Problems with Internet Access
- 37.5 Problems with the Password
- 37.6 Problems with the Web Configurator
- 37.7 Problems with a Telephone or the Telephone Port
- 37.8 Problems with Voice Service
- 37.9 Pop-up Windows, JavaScripts and Java Permissions
- Product Specifications
- Wall-mounting Instructions
- Setting up Your Computer’s IP Address
- IP Subnetting
- PPPoE
- Triangle Route
- SIP Passthrough
- Index
P-2302R Series User’s Guide
Chapter 7 Introduction to VoIP 98
Figure 34 Port Restricted Cone NAT Example
7.3.2.4 Symmetric NAT
The full, restricted and port restricted cone NAT types use the same mapping for an outgoing
packet’s source address regardless of the destination IP address and port. In symmetric NAT,
the mapping of an outgoing packet’s source address to a source address in another network is
different for each different destination IP address and port.
In the following example, the NAT router maps the Prestige’s source address IP address 1 and
port A to IP address 2 and port B on the external network for packets sent to IP address 3 and
port B. The NAT router uses a different mapping (IP address 2 and port M) when the Prestige
sends packets to IP address 4 and port D.
A host on the external network (IP address 3 and port C for example) can only send packets to
the internal host via the external IP address and port that the NAT router used in sending a
packet to the external host’s IP address and port. So in the example, only 3, C is allowed to
send packets to 2, B and only 4, D is allowed to send packets to 2, M.