P-2302R-P1 Series User’s Guide
Chapter 8 NAT
109
1
Jane requests a file from the Real Audio server (port 7070).
2
Port 7070 is a “trigger” port and causes the ZyXEL Device to record Jane’s computer IP
address. The ZyXEL Device associates Jane's computer IP address with the "incoming"
port range of 6970-7170.
3
The Real Audio server responds using a port number ranging between 6970-7170.
4
The ZyXEL Device forwards the traffic to Jane’s computer IP address.
5
Only Jane can connect to the Real Audio server until the connection is closed or times
out. The ZyXEL Device times out in three minutes with UDP (User Datagram Protocol),
or two hours with TCP/IP (Transfer Control Protocol/Internet Protocol).
8.1.2.2 Two Points To Remember About Trigger Ports
1
Trigger events only happen on data that is going coming from inside the ZyXEL Device
and going to the outside.
2
If an application needs a continuous data stream, that port (range) will be tied up so that
another computer on the LAN can’t trigger it.
8.1.3 SIP ALG
Some NAT routers may include a SIP Application Layer Gateway (ALG). A SIP ALG allows
SIP calls to pass through NAT by examining and translating IP addresses embedded in the
data stream. When the ZyXEL Device registers with the SIP register server, the SIP ALG
translates the ZyXEL Device’s private IP address inside the SIP data stream to a public IP
address. You do not need to use STUN or an outbound proxy (see
Chapter 9 on page 115
) if
your ZyXEL Device is behind a SIP ALG.
8.2 NAT Screens
8.2.1 NAT General Screen
Use this screen to enable and disable NAT and to allocate memory for NAT and firewall rules.
To access this screen, click
Network > NAT > General
.
Summary of Contents for P-2302R-P1 Series
Page 1: ...P 2302R P1 Series VoIP ATA Station Gateway User s Guide Version 3 60 Edition 1 5 2006...
Page 2: ......
Page 5: ...P 2302R P1 Series User s Guide Certifications 5...
Page 10: ...P 2302R P1 Series User s Guide 10 Customer Support...
Page 38: ...P 2302R P1 Series User s Guide 38 Chapter 1 Introducing the ZyXEL Device...
Page 46: ...P 2302R P1 Series User s Guide 46 Chapter 2 Introducing the Web Configurator...
Page 106: ...P 2302R P1 Series User s Guide 106 Chapter 7 LAN...
Page 125: ...P 2302R P1 Series User s Guide Chapter 9 SIP 125 Figure 60 VoIP SIP SIP Settings Advanced...
Page 130: ...P 2302R P1 Series User s Guide 130 Chapter 9 SIP...
Page 140: ...P 2302R P1 Series User s Guide 140 Chapter 10 Phone...
Page 146: ...P 2302R P1 Series User s Guide 146 Chapter 11 Phone Book...
Page 160: ...P 2302R P1 Series User s Guide 160 Chapter 14 Content Filter...
Page 174: ...P 2302R P1 Series User s Guide 174 Chapter 15 Bandwidth MGMT...
Page 184: ...P 2302R P1 Series User s Guide 184 Chapter 17 Static Route...
Page 208: ...P 2302R P1 Series User s Guide 208 Chapter 19 System...
Page 224: ...P 2302R P1 Series User s Guide 224 Chapter 20 Logs...
Page 234: ...P 2302R P1 Series User s Guide 234 Appendix A Product Specifications...
Page 256: ...P 2302R P1 Series User s Guide 256 Appendix C IP Subnetting...
Page 258: ...P 2302R P1 Series User s Guide 258 Appendix D SIP Passthrough...
Page 288: ...P 2302R P1 Series User s Guide 288 Appendix G Services...