Linksys RT31P2 - Broadband Router Guide

A Division of Cisco Systems, Inc.
®
Model No.
RT31P2
with 2 Phone Ports
Broadband Router
Installation and Troubleshooting Guide
VoIP
VoIP

Broadband Router with 2 Phone Ports
Copyright and Trademarks
Specifications are subject to change without notice. Linksys is a registered trademark or trademark of Cisco Systems,
Inc. and/or its affiliates in the U.S. and certain other countries. Copyright © 2004 Cisco Systems, Inc. All rights
reserved. Other brands and product names are trademarks or registered trademarks of their respective holders.
How to Use this Guide
Your guide to the Broadband Router has been designed to make understanding networking with the Phone
Adapter easier than ever. Look for the following items when reading this Guide:
In addition to these symbols, there are definitions for technical terms that are presented like this:
Also, each figure (diagram, screenshot, or other image) is provided with a figure number and description, like
this:
Figure numbers and descriptions can also be found in the “List of Figures” section.
This exclamation point means there is a caution or warning and is
something that could damage your property or the Router.
This question mark provides you with a reminder about something you
might need to do while using the Router.
This checkmark means there is a note of interest and is something you
should pay special attention to while using the Router.
word: definition.
Figure 0-1: Sample Figure Description
RT31P2-UG-41011H BW
WARNING: This product contains chemicals, including lead, known to the State of California to cause
cancer, and birth defects or other reproductive harm. Wash hands after handling.

Broadband Router with 2 Phone Ports
Table of Contents
Chapter 1: Introduction 1
Welcome 1
What’s in this Guide? 2
Chapter 2: Networking Basics 5
An Introduction to Local Area Networks 5
The Use of IP Addresses 5
Chapter 3: Getting to Know the Router 7
The Back Panel 7
The Front Panel 8
Chapter 4: Connecting the Router 11
Overview 11
Connection Instructions 12
Chapter 5: Configuring the Router 13
Overview 13
How to Access the Web-based Utility 15
The Setup Tab - Basic Setup 16
The Setup Tab - DDNS 23
The Setup Tab - MAC Address Clone 25
The Setup Tab - Advanced Routing 26
The Security Tab - Filter 28
The Security Tab - VPN Passthrough 30
The Voice Tab 31
The Applications & Gaming Tab - Port Range Forwarding 31
The Applications & Gaming Tab - Port Triggering 32

Broadband Router with 2 Phone Ports
The Applications & Gaming Tab - UPnP Forwarding 33
The Applications & Gaming Tab - DMZ 36
The Applications & Gaming Tab - QoS 37
The Administration Tab - Management 40
The Administration Tab - Log 42
The Administration Tab - Factory Defaults 43
The Administration Tab - Firmware Upgrade 43
The Status Tab - Voice 44
The Status Tab - Router 45
The Status Tab - Local Network 46
Appendix A: Troubleshooting 47
Common Problems and Solutions 47
Frequently Asked Questions 61
Appendix B: Finding the MAC Address and IP Address for Your Ethernet Adapter 67
Windows 98 or Me Instructions 67
Windows 2000 or XP Instructions 68
For the Router’s Web-based Utility 68
Appendix C: Windows Help 69
Appendix D: Glossary 71
Appendix E: Specifications 77
Appendix F: Warranty Information 79
Appendix G: Regulatory Information 81
Appendix H: Contact Information 83

Broadband Router with 2 Phone Ports
List of Figures
Figure 3-1: Back Panel 7
Figure 3-2: Front Panel 8
Figure 4-1: Router Connection Diagram 11
Figure 4-1: Connect a PC 12
Figure 4-2: Connect a Telephone 12
Figure 4-3: Connect the Modem 12
Figure 4-4: Connect the Power 12
Figure 5-1: Router’s IP Address 15
Figure 5-2: Router Login 15
Figure 5-3: Setup Tab - Basic Setup (Obtain an IP automatically) 16
Figure 5-4: Static IP 17
Figure 5-5: PPPoE 18
Figure 5-6: RAS (for Singtel) 18
Figure 5-7: PPTP 19
Figure 5-8: Heart Beat Signal 20
Figure 5-9: Setup Tab - DDNS (DynDNS.org) 24
Figure 5-10: Setup Tab - DDNS (TZO.com) 24
Figure 5-11: Setup Tab - MAC Address Clone 25
Figure 5-12: Setup Tab - Advanced Routing 26
Figure 5-13: Routing Table Entry List 27
Figure 5-14: Security Tab - Filter 28
Figure 5-15: Filtered MAC Address 29

Broadband Router with 2 Phone Ports
Figure 5-16: Security Tab - VPN Passthrough 30
Figure 5-17: Voice Tab 31
Figure 5-18: Applications & Gaming Tab - Port Range Forwarding 31
Figure 5-19: Applications & Gaming Tab - Port Triggering 32
Figure 5-20: Applications & Gaming Tab - UPnP Forwarding 33
Figure 5-21: Applications & Gaming Tab - DMZ 36
Figure 5-22: Applications & Gaming Tab - QoS 37
Figure 5-23: Administration Tab - Management 40
Figure 5-24: Back up & Restore Configuration 41
Figure 5-25: Administration Tab - Log 42
Figure 5-26: Incoming Log Table 42
Figure 5-27: Outgoing Log Table 42
Figure 5-28: Administration Tab - Factory Defaults 43
Figure 5-29: Administration Tab - Firmware Upgrade 43
Figure 5-30: Status Tab - Voice 44
Figure 5-31: Status Tab - Router 45
Figure 5-32: Status Tab - Local Network 46
Figure 5-33: DHCP Active IP Table 46
Figure B-1: IP Configuration Screen 67
Figure B-2: MAC/Adapter Address 67
Figure B-3: MAC/Physical Address 68
Figure B-4: MAC Address Clone 68
Figure B-5: MAC Address Filter 68

Broadband Router with 2 Phone Ports
1
Chapter 1: Introduction
Welcome
Chapter 1: Introduction
Welcome
Thank you for choosing the Broadband Router with 2 Phone Ports. This Router will allow your computers to share
a high-speed Internet connection as well as resources, including files and printers. And after you have set up
your Internet phone service, you will be able to make phone or fax calls using your Internet connection.
How does the Router do all of this? By connecting your computers and peripherals, including phones or fax
machines, to the Router and connecting the Router to your cable or DSL modem, then the Router can direct and
control communications for your network.
But what does all of this mean?
Networks are useful tools for sharing Internet access and computer resources. Multiple computers can share
Internet access, so you don’t need more than one high-speed Internet connection. With Internet phone service,
your Internet access can now be shared by your phones or fax machines as well. You will be able to make phone
calls using the account you set up with your Internet phone service, even while you’re surfing the Internet. Plus,
you can access one printer from different computers and access data located on another computer’s hard drive.
Networks are even used for playing multiplayer video games. So, networks not only are useful in homes and
offices, but also can
be fun.
PCs on a wired network create a LAN, or Local Area Network. They are connected with Ethernet cables, which is
why the network is called “wired”. ethernet: an IEEE standard network
protocol that specifies how data is placed
on and retrieved from a common
transmission medium.
lan (local area network): the computers
and networking products that make up
the network in your home or office.

Broadband Router with 2 Phone Ports
2Chapter 1: Introduction
What’s in this Guide?
To create your network, install and set up the Router. To guide you through the process, Linksys strongly
recommends that you run the Setup Wizard on the Setup CD-ROM. If you prefer to manually set up the Router,
use the instructions in the Quick Installation or this Installation and Troubleshooting Guide to help you. These
instructions should be all you need to get the most out of the Router.
What’s in this Guide?
This guide covers the basic steps for setting up a network with a router. After going through “Chapter 3: Getting
to Know the Router,” most users will only need to use the following chapters:
• Chapter 4: Connecting the Router
This chapter instructs you on how to connect the Router to your cable or DSL modem, PCs, and telephones
(or fax machines).
• Chapter 5: Configuring the Router
This chapter explains how to configure the Router using your web browser and the Router’s Web-based
Utility. You will configure the Router using the settings provided by your ISP.
When you’re finished with the basic steps, then you are ready to connect to the Internet.
You also have other chapters available for reference:
• Chapter 1: Introduction
This chapter describes the Router’s applications and this Installation and Troubleshooting Guide.
• Chapter 2: Networking Basics
This chapter briefly explains how a network functions.

Broadband Router with 2 Phone Ports
3
Chapter 1: Introduction
What’s in this Guide?
• Appendix A: Troubleshooting
This appendix describes some possible problems and solutions, as well as frequently asked questions,
regarding installation and use of the Router.
• Appendix B: Finding the MAC Address and IP Address for Your Ethernet Adapter
This appendix instructs you on how to find the MAC address or Ethernet address of your PC’s Ethernet
network adapter.
• Appendix C: Windows Help
This appendix describes how you can use Windows Help for instructions about networking, such as
installing the TCP/IP protocol.
• Appendix D: Glossary
This appendix gives a brief glossary of terms frequently used in networking.
• Appendix E: Specifications
This appendix provides the technical specifications for the Router.
• Appendix F: Warranty Information
This appendix supplies the warranty information for the Router.
• Appendix G: Regulatory Information
This appendix supplies the regulatory information regarding the Router.
• Appendix H: Contact Information
This appendix provides contact information for a variety of Linksys resources, including Technical Support.

Broadband Router with 2 Phone Ports
4Chapter 1: Introduction
What’s in this Guide?

Broadband Router with 2 Phone Ports
5
Chapter 2: Networking Basics
An Introduction to Local Area Networks
Chapter 2: Networking Basics
An Introduction to Local Area Networks
Simply put, a router is a network device that connects two networks together.
The Router connects your local area network (LAN), or the group of PCs in your home or office, to the Internet.
The Router processes and regulates the data that travels between these two networks.
The Router’s Network Address Translation (NAT) technology protects your network of PCs so users on the
Internet cannot “see” your PCs. This is how your LAN remains private. The Router protects your network by
inspecting the first packet coming in through the Internet port before delivery to the final destination on one of
the Ethernet ports. The Router inspects Internet port services like the web server, ftp server, or other Internet
applications, and, if allowed, it will forward the packet to the appropriate PC on the LAN side.
The Use of IP Addresses
IP stands for Internet Protocol. Every device in an IP-based network, including PCs, print servers, and routers,
requires an IP address to identify its location, or address, on the network. This applies to both the Internet and
LAN connections.
There are two ways of assigning IP addresses to your network devices.
A static IP address is a fixed IP address that you assign manually to a PC or other device on the network. Since a
static IP address remains valid until you disable it, static IP addressing ensures that the device assigned it will
always have that same IP address until you change it. Static IP addresses are commonly used with network
devices such as server PCs or print servers.
static ip address: a fixed address
assigned to a computer or device that is
connected to a network.
nat (network address translation): NAT
technology translates IP addresses of a
local area network to a different IP
address for the Internet.

Broadband Router with 2 Phone Ports
6Chapter 2: Networking Basics
The Use of IP Addresses
If you use the Router to share your cable or DSL Internet connection, contact your ISP to find out if they have
assigned a static IP address to your account. If so, you will need that static IP address when configuring the
Router. You can get the information from your ISP.
A dynamic IP address is automatically assigned to a device on the network. These IP addresses are called
dynamic because they are only temporarily assigned to the PC or other device. After a certain time period, they
expire and may change. If a PC logs onto the network (or the Internet) and its dynamic IP address has expired,
the DHCP server will assign it a new dynamic IP address.
A DHCP server can either be a designated PC on the network or another network device, such as the Router. By
default, the Router’s Internet Connection Type is Obtain an IP automatically (DHCP).
The PC or network device obtaining an IP address is called the DHCP client. DHCP frees you from having to
assign IP addresses manually every time a new user is added to your network.
For DSL users, many ISPs may require you to log on with a user name and password to gain access to the
Internet. This is a dedicated, high-speed connection type called Point to Point Protocol over Ethernet (PPPoE).
PPPoE is similar to a dial-up connection, but PPPoE does not dial a phone number when establishing a
connection. It also will provide the Router with a dynamic IP address to establish a connection to the Internet.
By default, a DHCP server (on the LAN side) is enabled on the Router. If you already have a DHCP server running
on your network, you MUST disable one of the two DHCP servers. If you run more than one DHCP server on your
network, you will experience network errors, such as conflicting IP addresses. To disable DHCP on the Router,
see the Basic Setup section in “Chapter 5: Configuring the Router.”
dynamic ip address: a temporary IP
address assigned by a DHCP server.
dhcp (dynamic host configuration
protocol): a protocol that lets one device
on a local network, known as a DHCP
server, assign temporary IP addresses to
the other network devices, typically
computers.

Broadband Router with 2 Phone Ports
7
Chapter 3: Getting to Know the Router
The Back Panel
Chapter 3: Getting to Know the Router
The Back Panel
The Router’s ports and the Reset button are located on the back panel of the Router.
Internet This Internet port connects to your cable or DSL modem.
Phone1 For your primary Internet phone line, the Phone1 port allows you to connect the Router to
your telephone (or fax machine) using an RJ-11 telephone cable (not included).
Phone2 If you have a second Internet phone line, the Phone2 port allows you to connect the
Router to your second telephone (or fax machine) using an RJ-11 telephone cable (not
included).
Ethernet 1-3 These three Ethernet ports connect to network devices, such as PCs or more switches.
Reset Button There are two ways to reset the Router's factory defaults. Either press the Reset Button,
for five seconds, or restore the defaults from the Router's Web-based Utility.
Figure 3-1: Back Panel
NOTE: The Factory Default
feature of the Router’s Web-
based Utility is protected by a
password available only from
your Internet phone service
provicer. Contact your service
for more information.

Broadband Router with 2 Phone Ports
8Chapter 3: Getting to Know the Router
The Front Panel
Power The Power port is where you will connect the power adapter.
The Front Panel
The Router’s LEDs, which inform you about
network activities, are located on the front
panel.
Power Green. The Power LED lights up when the Router is powered on. If the LED is flashing, the
Router is booting up, running a system self-test, or upgrading its firmware.
Ethernet 1-3 Green. The Ethernet LED serves two purposes. If the LED is solidly lit, the Router is
connected to a device through the corresponding port (Ethernet 1, 2, or 3). If the LED is
flashing, the Router is sending or receiving data over that port.
Phone 1-2 Green. The Phone LED is solidly lit when a telephone or fax machine has a registered
connection to your Internet phone line through the corresponding port (Phone 1 or Phone 2).
(The connection is registered if your Internet phone service account is active.) This LED is
not lit when there is no registered connection. It flashes when the phone is being used or an
incoming call has been detected.
Figure 3-2: Front Panel

Broadband Router with 2 Phone Ports
9
Chapter 3: Getting to Know the Router
The Front Panel
Internet Green. The Internet LED lights up when the Router is connected to your cable or DSL
modem. If the LED is flashing, the Router is sending or receiving data over the Internet port.
Proceed to “Chapter 4: Connecting the Router.”

Broadband Router with 2 Phone Ports
10 Chapter 3: Getting to Know the Router
The Front Panel

Broadband Router with 2 Phone Ports
11
Chapter 4: Connecting the Router
Overview
Chapter 4: Connecting the Router
Overview
To begin installation of the Router, you will connect the Router to your PCs, telephone(s) or fax machine(s), and
cable or DSL modem. The following connection diagram illustrates a basic network setup with one desktop PC
and telephone.
Figure 4-1: Router Connection Diagram
Telephone
Router
Cable/DSL
Modem
Internet
PC

Broadband Router with 2 Phone Ports
12 Chapter 4: Connecting the Router
Connection Instructions
Connection Instructions
1. Before you begin, make sure that all of your hardware is powered off, including the Router, PCs, switches,
and cable or DSL modem.
2. Connect one end of an Ethernet network cable to one of the numbered ports on the back of the Router.
Connect the other end to an Ethernet port on a network device, e.g., a PC, print server, or switch.
Repeat this step to connect more PCs or other network devices to the Router.
3. If necessary, disconnect the RJ-11 telephone cable of your telephone from the telephone wall jack. Then
connect that end to the Router’s Phone1 port.
4. If you have a second Internet phone or fax line, repeat step 3 to connect a telephone or fax machine to the
Router’s Phone2 port.
5. Connect your cable or DSL modem’s Ethernet cable to the Router’s Internet port.
6. Power on the cable or DSL modem.
7. Connect the included power adapter to the Router’s Power port, and then plug the power adapter into an
electrical outlet. The Power LED on the front panel will light up when the adapter is connected properly.
8. Power on your PC(s).
Proceed to “Chapter 5: Configuring the Router.”
Figure 4-2: Connect a Telephone
Figure 4-3: Connect the Modem
Figure 4-1: Connect a PC
NOTE: Make sure your telephone is set to its tone setting (not pulse).
Figure 4-4: Connect the Power

Broadband Router with 2 Phone Ports
13
Chapter 5: Configuring the Router
Overview
Chapter 5: Configuring the Router
Overview
Linksys recommends using the Setup CD-ROM for first-time installation of the Router. If you do not wish to run
the Setup Wizard on the Setup CD-ROM, then you can use the Web-based Utility to configure the Router. For
advanced users, you may configure the Router’s advanced settings through the Web-based Utility.
This chapter will describe each web page on the Utility and each page’s key functions. The Utility can be
accessed via your web browser through use of a computer connected to the Router. For a basic network setup,
most users only have to use the following screens of the Utility:
•BasicSetup.OntheBasic Setup screen, enter the Internet connection settings provided by your ISP. If you do
not have this information, you can call your ISP to request the settings. Once you have the setup information
for your specific type of Internet connection, then you can configure the Router.
• Management. Click the Administration tab and then the Management tab. The Router’s default password
is admin. To secure the Router, change the Password from its default.
There are six main tabs: Setup, Security, Voice, Applications & Gaming, Administration, and Status. Additional
tabs will be available after you click one of the main tabs.
Setup
• Basic Setup. Enter the Internet connection and network settings on this screen.
• DDNS. Enable the Router’s Dynamic Domain Name System (DDNS) feature on this screen.

Broadband Router with 2 Phone Ports
14 Chapter 5: Configuring the Router
Overview
• MAC Address Clone. If you need to clone a MAC address onto the Router, use this screen.
• Advanced Routing. On this screen, you can alter Network Address Translation (NAT), Dynamic Routing, and
Static Routing configurations.
Security
• Filter. To block specific users from Internet access, you can set up IP address, port, and MAC address
filtering.
• VPN Passthrough. To enable or disable IPSec, PPPoE, and/or PPTP Passthrough, use this screen.
Voice
Access to the Voice tab is restricted by your Internet phone service provider. Contact your provider for more
information.
Applications & Gaming
• Port Range Forwarding. Set up public services or other specialized Internet applications on your network.
• Port Triggering. To set up triggered ranges and forwarded ranges for Internet applications, click this tab.
• UPnP Forwarding. Use this screen to alter UPnP forwarding settings.
• DMZ. Click this tab to allow one local user to be exposed to the Internet for use of special-purpose services.
• QoS. Enable QoS (Quality of Service) to maximize network performance.