Chapter 21 ALG
ZyWALL USG 300 User’s Guide
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• There should be only one SIP server (total) on the ZyWALL’s private networks.
Any other SIP servers must be on the WAN. So for example you could have a
Back-to-Back User Agent such as the IPPBX x6004 or an asterisk PBX on the
DMZ or on the LAN but not on both.
• Using the SIP ALG allows you to use bandwidth management on SIP traffic.
• The SIP ALG handles SIP calls that go through NAT or that the ZyWALL routes.
You can also make other SIP calls that do not go through NAT or routing.
Examples would be calls between LAN IP addresses that are on the same
subnet.
• The SIP ALG supports peer-to-peer SIP calls. The firewall (by default) allows
peer to peer calls from the LAN zone to go to the WAN zone and blocks peer to
peer calls from the WAN zone to the LAN zone.
• The SIP ALG allows UDP packets with a specified port destination to pass
through.
• The ZyWALL allows SIP audio connections.
• You do not need to use TURN (Traversal Using Relay NAT) for VoIP devices
behind the ZyWALL when you enable the SIP ALG.
• Configuring the SIP ALG to use custom port numbers for SIP traffic also
configures the application patrol (see
) to use the same
port numbers for SIP traffic. Likewise, configuring the application patrol to use
custom port numbers for SIP traffic also configures SIP ALG to use the same
port numbers for SIP traffic.
Peer-to-Peer Calls and the ZyWALL
The ZyWALL ALG can allow peer-to-peer VoIP calls for both H.323 and SIP. You
must configure the firewall and NAT (port forwarding) to allow incoming (peer-to-
peer) calls from the WAN to a private IP address on the LAN (or DMZ).
VoIP Calls from the WAN with Multiple Outgoing Calls
When you configure the firewall and NAT (port forwarding) to allow calls from the
WAN to a specific IP address on the LAN, you can also use policy routing to have
H.323 (or SIP) calls from other LAN or DMZ IP addresses go out through a
different WAN IP address. The policy routing lets the ZyWALL correctly forward the
return traffic for the calls initiated from the LAN IP addresses.
For example, you configure the firewall and NAT to allow LAN IP address
A
to
receive calls from the Internet through WAN IP address
1
. You also use a policy
route to have LAN IP address
A
make calls out through WAN IP address
1
.
Configure another policy route to have H.323 (or SIP) calls from LAN IP addresses
B
and
C
go out through WAN IP address
2
. Even though only LAN IP address
A
Summary of Contents for USG-300 - V2.20 ED 2
Page 2: ......
Page 30: ...Table of Contents ZyWALL USG 300 User s Guide 30 ...
Page 31: ...31 PART I User s Guide ...
Page 32: ...32 ...
Page 38: ...Chapter 1 Introducing the ZyWALL ZyWALL USG 300 User s Guide 38 ...
Page 46: ...Chapter 2 Features and Applications ZyWALL USG 300 User s Guide 46 ...
Page 64: ...Chapter 3 Web Configurator ZyWALL USG 300 User s Guide 64 ...
Page 74: ...Chapter 4 Installation Setup Wizard ZyWALL USG 300 User s Guide 74 ...
Page 116: ...Chapter 6 Configuration Basics ZyWALL USG 300 User s Guide 116 ...
Page 184: ...Chapter 7 Tutorials ZyWALL USG 300 User s Guide 184 ...
Page 221: ...Chapter 8 L2TP VPN Example ZyWALL USG 300 User s Guide 221 ...
Page 222: ...Chapter 8 L2TP VPN Example ZyWALL USG 300 User s Guide 222 ...
Page 223: ...223 PART II Technical Reference ...
Page 224: ...224 ...
Page 238: ...Chapter 9 Dashboard ZyWALL USG 300 User s Guide 238 ...
Page 282: ...Chapter 10 Monitor ZyWALL USG 300 User s Guide 282 ...
Page 378: ...Chapter 14 Trunks ZyWALL USG 300 User s Guide 378 ...
Page 394: ...Chapter 15 Policy and Static Routes ZyWALL USG 300 User s Guide 394 ...
Page 408: ...Chapter 16 Routing Protocols ZyWALL USG 300 User s Guide 408 ...
Page 428: ...Chapter 19 NAT ZyWALL USG 300 User s Guide 428 ...
Page 433: ...Chapter 20 HTTP Redirect ZyWALL USG 300 User s Guide 433 ...
Page 434: ...Chapter 20 HTTP Redirect ZyWALL USG 300 User s Guide 434 ...
Page 456: ...Chapter 23 Authentication Policy ZyWALL USG 300 User s Guide 456 ...
Page 474: ...Chapter 24 Firewall ZyWALL USG 300 User s Guide 474 ...
Page 515: ...Chapter 25 IPSec VPN ZyWALL USG 300 User s Guide 515 ...
Page 516: ...Chapter 25 IPSec VPN ZyWALL USG 300 User s Guide 516 ...
Page 529: ...Chapter 26 SSL VPN ZyWALL USG 300 User s Guide 529 ...
Page 530: ...Chapter 26 SSL VPN ZyWALL USG 300 User s Guide 530 ...
Page 540: ...Chapter 27 SSL User Screens ZyWALL USG 300 User s Guide 540 ...
Page 542: ...Chapter 28 SSL User Application Screens ZyWALL USG 300 User s Guide 542 ...
Page 550: ...Chapter 29 SSL User File Sharing ZyWALL USG 300 User s Guide 550 ...
Page 635: ...Chapter 34 IDP ZyWALL USG 300 User s Guide 635 ...
Page 636: ...Chapter 34 IDP ZyWALL USG 300 User s Guide 636 ...
Page 646: ...Chapter 35 ADP ZyWALL USG 300 User s Guide 646 Figure 448 Profiles Protocol Anomaly ...
Page 657: ...Chapter 35 ADP ZyWALL USG 300 User s Guide 657 ...
Page 658: ...Chapter 35 ADP ZyWALL USG 300 User s Guide 658 ...
Page 690: ...Chapter 37 Content Filter Reports ZyWALL USG 300 User s Guide 690 ...
Page 708: ...Chapter 38 Anti Spam ZyWALL USG 300 User s Guide 708 ...
Page 730: ...Chapter 39 Device HA ZyWALL USG 300 User s Guide 730 ...
Page 746: ...Chapter 40 User Group ZyWALL USG 300 User s Guide 746 ...
Page 752: ...Chapter 41 Addresses ZyWALL USG 300 User s Guide 752 ...
Page 764: ...Chapter 43 Schedules ZyWALL USG 300 User s Guide 764 ...
Page 780: ...Chapter 45 Authentication Method ZyWALL USG 300 User s Guide 780 ...
Page 802: ...Chapter 46 Certificates ZyWALL USG 300 User s Guide 802 ...
Page 814: ...Chapter 48 SSL Application ZyWALL USG 300 User s Guide 814 ...
Page 824: ...Chapter 49 Endpoint Security ZyWALL USG 300 User s Guide 824 ...
Page 876: ...Chapter 50 System ZyWALL USG 300 User s Guide 876 ...
Page 916: ...Chapter 54 Reboot ZyWALL USG 300 User s Guide 916 ...
Page 918: ...Chapter 55 Shutdown ZyWALL USG 300 User s Guide 918 ...
Page 938: ...Chapter 56 Troubleshooting ZyWALL USG 300 User s Guide 938 ...
Page 946: ...Chapter 57 Product Specifications ZyWALL USG 300 User s Guide 946 ...
Page 1118: ...Appendix F Open Software Announcements ZyWALL USG 300 User s Guide 1118 ...