Chapter 24 ALG Screen
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24.2 FTP
File Transfer Protocol (FTP) is an Internet file transfer service that operates on the Internet and
over TCP/IP networks. A system running the FTP server accepts commands from a system
running an FTP client. The service allows users to send commands to the server for uploading
and downloading files. The FTP ALG allows TCP packets with a port 21 destination to pass
through. If the FTP server is located on the LAN, you must also configure NAT port
forwarding and firewall rules if you want to allow access to the server from the WAN.
24.3 H.323
H.323 is a standard teleconferencing protocol suite that provides audio, data and video
conferencing. It allows for real-time point-to-point and multipoint communication between
client computers over a packet-based network that does not provide a guaranteed quality of
service. NetMeeting uses H.323.
24.4 RTP
When you make a VoIP call using H.323 or SIP, the RTP (Real time Transport Protocol) is
used to handle voice data transfer. See RFC 1889 for details on RTP.
24.4.1 H.323 ALG Details
• The H.323 ALG supports peer-to-peer H.323 calls.
• The H.323 ALG handles H.323 calls that go through NAT or that the ZyWALL routes.
You can also make other H.323 calls that do not go through NAT or routing. Examples
would be calls between LAN IP addresses that are on the same subnet.
• The H.323 ALG allows calls to go out through NAT. For example, you could make a call
from a private IP address on the LAN to a peer device on the WAN.
• You must configure the firewall and port forwarding to allow incoming (peer-to-peer)
calls from the WAN to a private IP address on the LAN (or DMZ or WLAN). The
following example shows H.323 signaling (1) and audio (2) sessions between H.323
devices A and B.
Figure 268
H.323 ALG Example
• The H.323 ALG operates on TCP packets with a port 1720 destination.
• The ZyWALL allows H.323 audio connections.
Summary of Contents for ADSL 2+ Security Gateway
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Page 25: ...Table of Contents ZyWALL 2 Plus User s Guide 25 Index 679 ...
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Page 88: ...Chapter 3 Wizard Setup ZyWALL 2 Plus User s Guide 88 ...
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Page 144: ...Chapter 6 LAN Screens ZyWALL 2 Plus User s Guide 144 ...
Page 180: ...Chapter 9 DMZ Screens ZyWALL 2 Plus User s Guide 180 ...
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Page 222: ...Chapter 11 Firewall ZyWALL 2 Plus User s Guide 222 ...
Page 252: ...Chapter 13 Content Filtering Reports ZyWALL 2 Plus User s Guide 252 ...
Page 328: ...Chapter 16 Authentication Server ZyWALL 2 Plus User s Guide 328 ...
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Page 346: ...Chapter 17 Network Address Translation NAT ZyWALL 2 Plus User s Guide 346 ...
Page 350: ...Chapter 18 Static Route ZyWALL 2 Plus User s Guide 350 ...
Page 398: ...Chapter 21 Remote Management ZyWALL 2 Plus User s Guide 398 ...
Page 416: ...Chapter 24 ALG Screen ZyWALL 2 Plus User s Guide 416 ...
Page 417: ...417 PART V Logs and Maintenance Logs Screens 419 Maintenance 447 ...
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Page 423: ...Chapter 25 Logs Screens ZyWALL 2 Plus User s Guide 423 Figure 274 LOGS Log Settings ...
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Page 474: ...Chapter 27 Introducing the SMT ZyWALL 2 Plus User s Guide 474 ...
Page 496: ...Chapter 30 LAN Setup ZyWALL 2 Plus User s Guide 496 ...
Page 504: ...Chapter 32 DMZ Setup ZyWALL 2 Plus User s Guide 504 ...
Page 508: ...Chapter 33 Wireless Setup ZyWALL 2 Plus User s Guide 508 ...
Page 556: ...Chapter 38 Filter Configuration ZyWALL 2 Plus User s Guide 556 ...
Page 570: ...Chapter 40 System Information Diagnosis ZyWALL 2 Plus User s Guide 570 ...
Page 586: ...Chapter 41 Firmware and Configuration File Maintenance ZyWALL 2 Plus User s Guide 586 ...
Page 594: ...Chapter 42 System Maintenance Menus 8 to 10 ZyWALL 2 Plus User s Guide 594 ...
Page 598: ...Chapter 43 Remote Management ZyWALL 2 Plus User s Guide 598 ...
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Page 612: ...Chapter 45 Troubleshooting ZyWALL 2 Plus User s Guide 612 ...
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Page 644: ...Appendix B Pop up Windows JavaScripts and Java Permissions ZyWALL 2 Plus User s Guide 644 ...
Page 668: ...Appendix E Importing Certificates ZyWALL 2 Plus User s Guide 668 ...
Page 672: ...Appendix F Legal Information ZyWALL 2 Plus User s Guide 672 ...
Page 678: ...Appendix G Customer Support ZyWALL 2 Plus User s Guide 678 ...