ZyWALL 35 User’s Guide
626
Appendix H SIP Passthrough
1
A sends a SIP INVITE request to B. This message is an invitation for B to participate in a
SIP telephone call.
2
B sends a response indicating that the telephone is ringing.
3
B sends an OK response after the call is answered.
4
A then sends an ACK message to acknowledge that B has answered the call.
5
Now A and B exchange voice media (talk).
6
After talking, A hangs up and sends a BYE request.
7
B replies with an OK response confirming receipt of the BYE request and the call is
terminated.
SIP Servers
SIP is a client-server protocol. A SIP client is an application program or device that sends SIP
requests. A SIP server responds to the SIP requests.
When you use SIP to make a VoIP call, it originates at a client and terminates at a server. A
SIP client could be a computer or a SIP phone. One device can act as both a SIP client and a
SIP server.
SIP User Agent Server
A SIP user agent server can make and receive VoIP telephone calls. This means that SIP can
be used for peer-to-peer communications even though it is a client-server protocol. In the
following figure, either A or B can act as a SIP user agent client to initiate a call. A and B can
also both act as a SIP user agent server to receive the call.
Figure 34
SIP User Agent Server
SIP Proxy Server
A SIP proxy server receives requests from clients and forwards them to another server.
3. OK
4. ACK
5.Dialogue (voice traffic)
6. BYE
7. OK
Table 29
SIP Call Progression (continued)
A
B
Summary of Contents for ZyXEL ZyWALL 35
Page 1: ...ZyWALL 35 Internet Security Appliance User s Guide Version 3 64 3 2005 ...
Page 2: ......
Page 38: ...ZyWALL 35 User s Guide 36 ...
Page 46: ...ZyWALL 35 User s Guide 44 ...
Page 74: ...ZyWALL 35 User s Guide 72 Chapter 2 Introducing the Web Configurator ...
Page 90: ...ZyWALL 35 User s Guide 88 Chapter 3 Wizard Setup ...
Page 100: ...ZyWALL 35 User s Guide 98 Chapter 4 LAN Screens ...
Page 106: ...ZyWALL 35 User s Guide 104 Chapter 5 Bridge Screens ...
Page 128: ...ZyWALL 35 User s Guide 126 Chapter 6 Wireless LAN ...
Page 135: ...ZyWALL 35 User s Guide Chapter 7 WAN Screens 133 Figure 47 General ...
Page 152: ...ZyWALL 35 User s Guide 150 Chapter 7 WAN Screens Figure 57 Dial Backup Setup ...
Page 158: ...ZyWALL 35 User s Guide 156 Chapter 7 WAN Screens ...
Page 166: ...ZyWALL 35 User s Guide 164 Chapter 8 DMZ Screens ...
Page 234: ...ZyWALL 35 User s Guide 232 Chapter 13 Introduction to IPSec ...
Page 275: ...ZyWALL 35 User s Guide Chapter 15 Certificates 273 Figure 129 My Certificate Details ...
Page 294: ...ZyWALL 35 User s Guide 292 Chapter 16 Authentication Server Figure 140 Local User Database ...
Page 314: ...ZyWALL 35 User s Guide 312 Chapter 17 Network Address Translation NAT ...
Page 318: ...ZyWALL 35 User s Guide 316 Chapter 18 Static Route ...
Page 324: ...ZyWALL 35 User s Guide 322 Chapter 19 Policy Route ...
Page 340: ...ZyWALL 35 User s Guide 338 Chapter 20 Bandwidth Management ...
Page 376: ...ZyWALL 35 User s Guide 374 Chapter 22 Remote Management ...
Page 390: ...ZyWALL 35 User s Guide 388 Chapter 24 Logs Screens Figure 198 Log Settings ...
Page 413: ...ZyWALL 35 User s Guide Chapter 25 Maintenance 411 Figure 220 Restart Screen ...
Page 414: ...ZyWALL 35 User s Guide 412 Chapter 25 Maintenance ...
Page 440: ...ZyWALL 35 User s Guide 438 Chapter 28 WAN and Dial Backup Setup ...
Page 456: ...ZyWALL 35 User s Guide 454 Chapter 31 DMZ Setup ...
Page 460: ...ZyWALL 35 User s Guide 458 Chapter 32 Route Setup ...
Page 470: ...ZyWALL 35 User s Guide 468 Chapter 33 Remote Node Setup ...
Page 522: ...ZyWALL 35 User s Guide 520 Chapter 39 System Information Diagnosis ...
Page 538: ...ZyWALL 35 User s Guide 536 Chapter 40 Firmware and Configuration File Maintenance ...
Page 550: ...ZyWALL 35 User s Guide 548 Chapter 42 Remote Management ...
Page 558: ...ZyWALL 35 User s Guide 556 Chapter 43 IP Policy Routing ...
Page 574: ...ZyWALL 35 User s Guide 572 Chapter 45 Troubleshooting Figure 364 Java Sun ...
Page 602: ...ZyWALL 35 User s Guide 600 Appendix C IP Subnetting ...
Page 608: ...ZyWALL 35 User s Guide 606 Appendix E PPTP ...
Page 626: ...ZyWALL 35 User s Guide 624 Appendix G Triangle Route ...
Page 656: ...ZyWALL 35 User s Guide 654 Appendix J Importing Certificates ...
Page 658: ...ZyWALL 35 User s Guide 656 Appendix K Command Interpreter ...
Page 664: ...ZyWALL 35 User s Guide 662 Appendix L Firewall Commands ...
Page 668: ...ZyWALL 35 User s Guide 666 Appendix M NetBIOS Filter Commands ...
Page 674: ...ZyWALL 35 User s Guide 672 Appendix O Brute Force Password Guessing Protection ...
Page 696: ...ZyWALL 35 User s Guide 694 Appendix Q Log Descriptions ...