ZyXEL Communications ZyWALL 1000 manual 18

Table of Contents

18.1	ALG Introduction ..............................................................................................................	265
18.1.1 Application Layer Gateway (ALG) and NAT ...........................................................		265
18.1.2 ALG and Trunks .....................................................................................................		265
18.1.3 FTP ........................................................................................................................		266
18.1.4 H.323 ......................................................................................................................		266
18.1.5 RTP ........................................................................................................................		266
18.1.6 SIP .........................................................................................................................		267
18.2	Peer-to-Peer Calls and the ZyWALL ...............................................................................	268
18.2.1 VoIP Calls from the WAN with Multiple Outgoing Calls ..........................................		268
18.2.2 VoIP with Multiple WAN IP Addresses ...................................................................		268
18.3	ALG Screen .....................................................................................................................	269
18.4	WAN to LAN SIP Peer-to-peer Calls Example ................................................................	271
Part III: Firewall and VPN.....................................................................		275
Chapter 19
Firewall.................................................................................................................................		277
19.1	Firewall Overview ............................................................................................................	277
19.2	Firewall Rules ..................................................................................................................	278
19.2.1 Rule Directions .......................................................................................................		278
19.2.2 Firewall and VPN Traffic .........................................................................................		280
19.3	Firewall Rule Example Applications ................................................................................	280
19.4	Alerts ...............................................................................................................................	282
19.5	Asymmetrical Routes .......................................................................................................	282
19.5.1 Virtual Interfaces and Asymmetrical Routes ..........................................................		283
19.6	Configuring the Firewall ...................................................................................................	283
19.6.1 Edit a Firewall Rule ................................................................................................		286
19.7	Firewall Rule Configuration Example ..............................................................................	287
Chapter 20
IPSec VPN..............................................................................................................................		291
20.1	IPSec VPN Overview .......................................................................................................	291
20.1.1 IPSec SA Overview ................................................................................................		292
20.1.2 Additional Topics for IPSec SA ...............................................................................		294
20.2	VPN Related Configuration .............................................................................................	296
20.3	VPN Connection Screens ................................................................................................	297
20.3.1 VPN Connection Summary ....................................................................................		297
20.3.2 VPN Connection Add/Edit IKE ..............................................................................		298
20.3.3 VPN Connection Add/Edit Manual Key ..................................................................		302
20.4 VPN Gateway Screens ...................................................................................................		306
20.4.1 IKE SA Overview ....................................................................................................		306

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	ZyWALL USG 1000 User’s Guide