ZyXEL Communications P-2602H - Manual (Page 16)

Table of Contents
P-2602H(W)(L)-DxA User’s Guide
16
12.8.4 Call Progression ..................................................................................................... 185
12.9 VoIP Trunking Example: PSTN to PSTN via VoIP ........................................................... 185
12.9.1 Background Information ......................................................................................... 186
12.9.2 Configuration Details: Outgoing ............................................................................. 186
12.9.3 Configuration Details: Incoming ............................................................................. 188
12.9.4 Call Progression ..................................................................................................... 188
Chapter 13
Phone Usage ......................................................................................................................... 191
13.1 Dialing a Telephone Number ........................................................................................... 191
13.2 Using Speed Dial to Dial a Telephone Number ............................................................... 191
13.3 Internal Calls .................................................................................................................... 191
13.4 Using Call Park and Pickup ............................................................................................. 191
13.5 Checking the ZyXEL Device’s IP Address ....................................................................... 192
13.6 Auto Provisioning and Auto Firmware Upgrade .............................................................. 192
13.7 Phone Functions Summary ............................................................................................. 192
Chapter 14
Firewalls................................................................................................................................. 195
14.1 Firewall Overview ........................................................................................................... 195
14.2 Types of Firewalls ............................................................................................................ 195
14.2.1 Packet Filtering Firewalls ....................................................................................... 195
14.2.2 Application-level Firewalls ...................................................................................... 196
14.2.3 Stateful Inspection Firewalls .................................................................................. 196
14.3 Introduction to ZyXEL’s Firewall ...................................................................................... 196
14.3.1 Denial of Service Attacks ....................................................................................... 197
14.4 Denial of Service ............................................................................................................. 197
14.4.1 Basics ..................................................................................................................... 197
14.4.2 Types of DoS Attacks ............................................................................................. 198
14.5 Stateful Inspection ........................................................................................................... 200
14.5.1 Stateful Inspection Process .................................................................................... 201
14.5.2 Stateful Inspection on Your ZyXEL Device ............................................................. 202
14.5.3 TCP Security .......................................................................................................... 202
14.5.4 UDP/ICMP Security ................................................................................................ 203
14.5.5 Upper Layer Protocols ........................................................................................... 203
14.6 Guidelines for Enhancing Security with Your Firewall ..................................................... 204
14.6.1 Security In General ................................................................................................ 204
14.7 Packet Filtering Vs Firewall ............................................................................................. 205
14.7.1 Packet Filtering: ..................................................................................................... 205
14.7.2 Firewall ................................................................................................................... 205
Chapter 15
Firewall Configuration .......................................................................................................... 207