338
Appendix L SIP
NN47923-501
SIP ALG
Some NAT routers can include a SIP Application Layer Gateway (ALG). A SIP
ALG allows VoIP calls to pass through NAT by examining and translating IP
addresses embedded in the data stream. When a VoIP device (SIP client) behind
the SIP ALG registers with the SIP register server, the SIP ALG translates the
device’s private IP address inside the SIP data stream to a public IP address. You
do not need to use STUN if your VoIP device is behind the SIP ALG.
STUN
Using STUN (Simple Traversal of User Datagram Protocol (UDP) through
Network Address Translators), the VoIP device can the presence and types of
NAT routers, firewalls, or both between it and the public Internet. With STUN,
the VoIP device can also find the public IP address that NAT assigned, so the
VoIP device can embed it in the SIP data stream. See “
STUN - Simple Traversal
of User Datagram Protocol (UDP) Through Network Address Translators
(NATs)
” (RFC 3489) for details on STUN.
Business Secure Router SIP ALG
•
SIP clients must be connected to the LAN. A SIP server must be on the WAN.
•
You can make and receive calls between the LAN and the WAN. You cannot
make a call between the LAN and the LAN.
•
The SIP ALG forwards UDP packets with a port 5060 destination to pass
through.
•
The Business Secure Router forwards SIP audio connections.
Содержание 252
Страница 13: ...Contents 13 Nortel Business Secure Router 252 Configuration Advanced SIP Register Server 337 RTP 337 Index 341 ...
Страница 14: ...14 Contents NN47923 501 ...
Страница 20: ...20 Figures NN47923 501 ...
Страница 24: ...24 Tables NN47923 501 ...
Страница 30: ...30 Preface NN47923 501 ...
Страница 42: ...42 Chapter 1 Getting to know your Nortel Business Secure Router 252 NN47923 501 ...
Страница 48: ...48 Chapter 2 Introducing the SMT NN47923 501 SMT menus at a glance Figure 6 SMT overview ...
Страница 72: ...72 Chapter 3 WAN and Dial Backup Setup NN47923 501 ...
Страница 80: ...80 Chapter 4 LAN setup NN47923 501 ...
Страница 84: ...84 Chapter 5 Internet access NN47923 501 ...
Страница 98: ...98 Chapter 6 Remote Node setup NN47923 501 ...
Страница 102: ...102 Chapter 7 IP Static Route Setup NN47923 501 ...
Страница 130: ...130 Chapter 9 Network Address Translation NAT NN47923 501 ...
Страница 156: ...156 Chapter 12 SNMP Configuration NN47923 501 ...
Страница 178: ...178 Chapter 14 System information and diagnosis NN47923 501 ...
Страница 198: ...198 Chapter 15 Firmware and configuration file maintenance NN47923 501 ...
Страница 212: ...212 Chapter 17 Remote Management NN47923 501 ...
Страница 232: ...232 Appendix B Triangle Route NN47923 501 ...
Страница 252: ...252 Appendix D PPPoE NN47923 501 ...
Страница 256: ...256 Appendix E Hardware specifications NN47923 501 ...
Страница 266: ...266 Appendix F IP subnetting NN47923 501 ...
Страница 308: ...308 Appendix H NetBIOS filter commands NN47923 501 ...
Страница 332: ...332 Appendix K Brute force password guessing protection NN47923 501 ...