User's Manual

Page 849 of 910
IP Line Description, Installation and Maintenance
856
Appendix A: NAT router requirements
for NAT Traversal feature
Contents
This section contains information on the following topics:
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849
Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 850
Cone NAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 850
Time-out configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 851
Hairpinning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 851
Unidirectional packet flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 852
Firmware versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 853
Natcheck output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854
Description
This appendix describes the requirements of a Network Address Translation
(NAT) router to enable it to support the NAT Traversal feature.
For a NAT device to work correctly between an IP Phone and the CS 1000
system, the following requirements must be met:
1 A cone NAT must be used.
2 The Private-to-Public mapping should have a long time-out configured.
3 If multiple IP Phones will be supported behind the same NAT router,
hairpinning must be supported.