ZyWALL 5 User’s Guide
590
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 5
Page 1: ...ZyWALL 5 Internet Security Appliance User s Guide Version 3 64 3 2005 ...
Page 2: ......
Page 26: ...ZyWALL 5 User s Guide 24 ...
Page 44: ...ZyWALL 5 User s Guide 42 ...
Page 86: ...ZyWALL 5 User s Guide 84 Chapter 3 Wizard Setup ...
Page 96: ...ZyWALL 5 User s Guide 94 Chapter 4 LAN Screens ...
Page 102: ...ZyWALL 5 User s Guide 100 Chapter 5 Bridge Screens ...
Page 130: ...ZyWALL 5 User s Guide 128 Chapter 7 WAN Screens Figure 45 WAN PPPoE Encapsulation ...
Page 138: ...ZyWALL 5 User s Guide 136 Chapter 7 WAN Screens Figure 50 Dial Backup Setup ...
Page 144: ...ZyWALL 5 User s Guide 142 Chapter 7 WAN Screens ...
Page 152: ...ZyWALL 5 User s Guide 150 Chapter 8 DMZ Screens ...
Page 179: ...ZyWALL 5 User s Guide Chapter 10 Firewall Screens 177 Figure 73 My Service Rule Configuration ...
Page 220: ...ZyWALL 5 User s Guide 218 Chapter 13 Introduction to IPSec ...
Page 238: ...ZyWALL 5 User s Guide 236 Chapter 14 VPN Screens Figure 110 VPN Rules IKE Network Policy Edit ...
Page 261: ...ZyWALL 5 User s Guide Chapter 15 Certificates 259 Figure 122 My Certificate Details ...
Page 280: ...ZyWALL 5 User s Guide 278 Chapter 16 Authentication Server Figure 133 Local User Database ...
Page 317: ...ZyWALL 5 User s Guide Chapter 19 Bandwidth Management 315 ...
Page 318: ...ZyWALL 5 User s Guide 316 Chapter 19 Bandwidth Management ...
Page 352: ...ZyWALL 5 User s Guide 350 Chapter 21 Remote Management ...
Page 366: ...ZyWALL 5 User s Guide 364 Chapter 23 Logs Screens Figure 188 Log Settings ...
Page 389: ...ZyWALL 5 User s Guide Chapter 24 Maintenance 387 Figure 210 Restart Screen ...
Page 390: ...ZyWALL 5 User s Guide 388 Chapter 24 Maintenance ...
Page 416: ...ZyWALL 5 User s Guide 414 Chapter 27 WAN and Dial Backup Setup ...
Page 432: ...ZyWALL 5 User s Guide 430 Chapter 30 DMZ Setup ...
Page 492: ...ZyWALL 5 User s Guide 490 Chapter 37 System Information Diagnosis ...
Page 508: ...ZyWALL 5 User s Guide 506 Chapter 38 Firmware and Configuration File Maintenance ...
Page 520: ...ZyWALL 5 User s Guide 518 Chapter 40 Remote Management ...
Page 536: ...ZyWALL 5 User s Guide 534 Chapter 42 Troubleshooting Figure 343 Java Sun ...
Page 564: ...ZyWALL 5 User s Guide 562 Appendix C IP Subnetting ...
Page 570: ...ZyWALL 5 User s Guide 568 Appendix E PPTP ...
Page 571: ...ZyWALL 5 User s Guide 569 ...
Page 572: ...ZyWALL 5 User s Guide 570 ...
Page 590: ...ZyWALL 5 User s Guide 588 Appendix G Triangle Route ...
Page 620: ...ZyWALL 5 User s Guide 618 Appendix J Importing Certificates ...
Page 622: ...ZyWALL 5 User s Guide 620 Appendix K Command Interpreter ...
Page 628: ...ZyWALL 5 User s Guide 626 Appendix L Firewall Commands ...
Page 632: ...ZyWALL 5 User s Guide 630 Appendix M NetBIOS Filter Commands ...
Page 638: ...ZyWALL 5 User s Guide 636 Appendix O Brute Force Password Guessing Protection ...
Page 660: ...ZyWALL 5 User s Guide 658 Appendix Q Log Descriptions ...