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