ZyXEL Communications P-2602HW(L) Series - Manual (Page 14)

P-2602H(W)(L)-DxA Series User’s Guide
14 Table of Contents
11.15.3 USA Type Supplementary Services ....................................................170
11.15.3.1 USA Call Hold ............................................................................170
11.15.3.2 USA Call Waiting ......................................................................171
11.15.3.3 USA Call Transfer ......................................................................171
11.15.3.4 USA Three-Way Conference .....................................................171
11.16 Phone Region Screen .................................................................................171
11.17 Speed Dial ....................................................................................................172
11.17.1 Peer-to-Peer Calls ..............................................................................172
11.18 Speed Dial Screen .......................................................................................173
11.19 Incoming Call Policy Screen ........................................................................174
11.20 PSTN Line Screen (“L” models only) ...........................................................176
Chapter 12
Phone Usage ........................................................................................................ 179
12.1 Dialing a Telephone Number ..........................................................................179
12.2 Using Speed Dial to Dial a Telephone Number ..............................................179
12.3 Internal Calls ..................................................................................................179
12.4 Checking the Device’s IP Address .................................................................179
12.5 Auto Firmware Upgrade .................................................................................180
Chapter 13
Firewalls................................................................................................................ 181
13.1 Firewall Overview ..........................................................................................181
13.2 Types of Firewalls ..........................................................................................181
13.2.1 Packet Filtering Firewalls ......................................................................181
13.2.2 Application-level Firewalls ....................................................................182
13.2.3 Stateful Inspection Firewalls ................................................................182
13.3 Introduction to ZyXEL’s Firewall .....................................................................182
13.3.1 Denial of Service Attacks ......................................................................183
13.4 Denial of Service ............................................................................................183
13.4.1 Basics ...................................................................................................183
13.4.2 Types of DoS Attacks ...........................................................................184
13.4.2.1 ICMP Vulnerability ......................................................................186
13.4.2.2 Illegal Commands (NetBIOS and SMTP) ....................................186
13.4.2.3 Traceroute ...................................................................................187
13.5 Stateful Inspection ..........................................................................................187
13.5.1 Stateful Inspection Process ..................................................................188
13.5.2 Stateful Inspection on Your ZyXEL Device ...........................................188
13.5.3 TCP Security .........................................................................................189
13.5.4 UDP/ICMP Security ..............................................................................189
13.5.5 Upper Layer Protocols ..........................................................................190
13.6 Guidelines for Enhancing Security with Your Firewall ....................................190
13.6.1 Security In General ...............................................................................190