ZyXEL Communications 2002 Series 5.3.2.1 Full Cone NAT, 5.3.2 NAT Types

Prestige 2002 Series User’s Guide

Figure 15 NAT

NAT does not translate IP addresses that are imbedded in the data stream. In order to make VoIP calls, the Prestige must register its public IP address with a SIP register server. The SIP register server gets the Prestige’s IP address from inside the SIP data stream and maps it to your SIP identity. If there is a NAT router between the Prestige and the SIP register server, the Prestige probably has a private IP address and it will be embedded in the data stream.

5.3.2 NAT Types

There are four types of NAT:

•Full Cone

•Restricted Cone

•Port Restricted Cone

•Symmetric

The first three NAT types use mapping for a private IP address that is independent of the destination address. Symmetric NAT allocates a new mapping for each different destination IP address. STUN does not work with symmetric NAT routers (see “Symmetric NAT”) or firewalls.

5.3.2.1 Full Cone NAT

In full cone NAT, all requests from the same private IP address and port are mapped to the same public IP address and port. Someone on the Internet only needs to know the mapping scheme in order to send packets to a device behind the NAT router. See the following figure. Computer A is behind a NAT router and has a private IP address of 10.0.0.3 and is sending and receiving packets on port 80. It is mapped to the public IP address a.b.c.d and port 30080. Anyone on the Internet (B and C in this example) can send packets to IP address a.b.c.d and port 30080 and the NAT router will send them to computer A (at IP address 10.0.0.3 port 80).

Chapter 5 Introduction to VoIP

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Contents

User’s Guide Page Copyright Disclaimer Trademarks Federal Communications Commission (FCC) Interference Statement Notice Certifications ZyXEL Limited Warranty Note Safety Warnings Customer Support Table of Contents Introduction to VoIP Phone Phone Book Maintenance Troubleshooting Appendix A Hardware Specifications Appendix B Appendix C List of Figures Page List of Tables Page Preface About This User's Guide Related Documentation User Guide Feedback Syntax Conventions Graphics Icons Key Introducing the Prestige 1.1 Prestige 2002 VoIP Analog Telephone Adaptor Overview 1.2Prestige 2002L VoIP Analog Telephone Adaptor with Lifeline 1.3 Features 10/100Mbps Auto-negotiatingFast Ethernet Interfaces PSTN Lifeline REN Dynamic Jitter Buffer Standards Compliance Multiple SIP Accounts 1.4 Applications 1.4.2 Make Calls via IP-PBX Page Page Introducing the Web Configurator 2.1 Web Configurator Overview 2.2Accessing the Prestige Web Configurator Apply Ignore MAIN MENU 2.3 Resetting the Prestige 2.4Navigating the Prestige Web Configurator Page 2.5 Common Screen Command Buttons Page System Screens 3.1 System Overview 3.2 General Setup 3.3 General Setup Configuration 3.4 Configuring Password 3.5 Pre-definedNTP Time Servers List 3.6 Configuring Time Setting Page Page Ethernet Screens 4.1 ETHERNET Overview 4.2 Configuring Ethernet Figure 10 ETHERNET Table 7 ETHERNET 4.3 Configuring the Ethernet Management Port Introduction to VoIP 5.1 Introduction to VoIP 5.2 Introduction to SIP 5.2.1.1 SIP Number 5.2.1.2 SIP Service Domain 5.2.3.1 SIP User Agent Server 5.2.3.2 SIP Proxy Server 5.2.3.3 SIP Redirect Server 5.2.3.4 SIP Register Server 5.3 STUN 5.3.2.1 Full Cone NAT 5.3.2.2 Restricted Cone NAT 5.3.2.3 Port Restricted Cone NAT 5.3.2.4 Symmetric NAT 5.4 SIP ALG 5.5 Pulse Code Modulation 5.6 Voice Coding 5.7 PSTN Call Setup Signaling VoIP Screens 6.1 VoIP Introduction 6.2 VoIP Configuration 6.3 Advanced VoIP Settings Configuration Page Page 6.4 Quality of Service (QoS) 6.4.2.1 DSCP and Per-HopBehavior 6.5 QoS Configuration Phone 7.1 Phone Introduction 7.2 Phone Port Configuration Figure 24 Phone Port Phone Book 8.1 Phone Book Introduction 8.1.1.1 Peer-to-PeerCalls 8.2 Speed Dial Configuration Figure 25 Phone Book 8.3 Lifeline Configuration (Prestige 2002L) Page Logs 9.1 Viewing Logs 9.1.1 Log Message Descriptions Table 19 SIP Logs Table 20 RTP Logs Page Maintenance 10.1 Maintenance Overview 10.2 Status Screen 10.3 F/W Upload Screen Firmware Upload in Process 10.4 Configuration Screen 10.4.1Backup Configuration Configuration Upload Error 10.4.3 Back to Factory Defaults Reset 10.5 Restart Screen Page Troubleshooting 11.1 Problems Starting Up the Prestige 11.2 Problems with the LAN or PC LED 11.3 Problems with the LAN Interface 11.4 Problems with Internet Access 11.5 Problems with the Password 11.6 Problems with the Web Configurator 11.7 Problems with Telephone or Telephone Port 11.8 Problems with Voice Service Appendix A Hardware Specifications Ethernet Port Specifications Prestige 2002 Power Adaptor Specifications Prestige 2002L Power Adaptor Specifications Appendix B Setting up Your Computer’s IP Address Windows 95/98/Me Installing Components Add Adapter Protocol Microsoft Configuring Obtain an IP address automatically Specify an IP address Subnet Mask DNS Windows 2000/NT/XP Network Connections Network and Dial-up Connections 3Right-click Local Area Connection and then click Properties Internet Protocol (TCP/IP) General Use the following IP Address IP address Subnet mask Default gateway Advanced Use the following DNS server addresses Preferred DNS server Alternate DNS server 8Click OK to close the Internet Protocol (TCP/IP) Properties window 9Click OK to close the Local Area Connection Properties window Macintosh OS 8/9 Macintosh OS Automatic Location •Select Built-inEthernet from the Show list Using DHCP Apply Now Appendix C IP Subnetting IP Addressing IP Classes Subnet Masks Subnetting Example: Two Subnets Page Example: Four Subnets Example Eight Subnets Subnetting With Class A and Class B Networks Page Appendix D PPPoE PPPoE in Action Benefits of PPPoE Traditional Dial-upScenario How PPPoE Works Prestige as a PPPoE Client Index