P-2302R-P1 Series User’s Guide
Appendix E NAT
267
Figure 145
Port Restricted Cone NAT Example
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 ZyXEL Device’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 ZyXEL Device 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
.
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...
