ZyXEL Communications P-2602 manual Chapter Phone Usage 179

P-2602H(W)(L)-DxA Series User’s Guide

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

14 Table of Contents