Yealink SIP-T4X Service manual

Copyright © 2013 YEALINK NETWORK TECHNOLOGY
Copyright © 2013 Yealink Network Technology CO., LTD. All rights reserved. No parts of this
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THE SPECIFICATIONS AND INFORMATION REGARDING THE PRODUCTS IN THIS GUIDE ARE
SUBJECT TO CHANGE WITHOUT NOTICE. ALL STATEMENTS, INFORMATION, AND
RECOMMENDATIONS IN THIS GUIDE ARE BELIEVED TO BE ACCURATE AND PRESENTED
WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. USERS MUST TAKE FULL
RESPONSIBILITY FOR THEIR APPLICATION OF PRODUCTS.
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REGARD TO THIS GUIDE, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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CO., LTD. shall not be liable for errors contained herein nor for incidental or consequential
damages in connection with the furnishing, performance, or use of this guide.
Hereby, Yealink Network Technology CO., LTD. declares that this phone is in conformity
with the essential requirements and other relevant provisions of the CE, FCC.
This device is marked with the CE mark in compliance with EC Directives 2006/95/EC and 2004/108/EC.
This device is compliant with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
1. This device may not cause harmful interference, and
2. This device must accept any interference received, including interference that may cause undesired
operation.

Note: This device is tested and complies with the limits for a Class B digital device, pursuant to Part 15 of the
FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a
residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions, may cause harmful interference to radio
communications. However, there is no guarantee that interference will not occur in a particular installation. If
this equipment does cause harmful interference to radio or television reception, which can be determined
by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more
of the following measures:
1. Reorient or relocate the receiving antenna.
2. Increase the separation between the equipment and receiver.
3. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
4. Consult the dealer or an experience radio/TV technician for help.
To avoid the potential effects on the environment and human health as a result of the
presence of hazardous substances in electrical and electronic equipment, end users of
electrical and electronic equipment should understand the meaning of the crossed-out
wheeled bin symbol. Do not dispose of WEEE as unsorted municipal waste and have to
collect such WEEE separately.
We are striving to improve our documentation quality and we appreciate your feedback. Email your
opinions and comments to [e-mail].

Yealink SIP-T4X IP phones firmware contain third-party software under the GNU General Public License
(GPL). Yealink uses software under the specific terms of the GPL. Please refer to the GPL for the exact terms
and conditions of the license.
The original GPL license, source code of components licensed under GPL and used in Yealink products can
be downloaded online:
http://www.yealink.com/GPLOpenSource.aspx?BaseInfoCateId=293&NewsCateId=293&CateId=293.

About This Guide
v
The guide is intended for administrators who need to properly configure, customize,
manage, and troubleshoot the IP phone system rather than the end-users. It provides
details on the functionality and configuration of SIP-T4X IP phones.
Many of the features described in this guide involve network settings, which could affect
the IP phone performance in the network. So an understanding of the IP networking and
prior knowledge of IP telephony concepts are necessary.
This guide covers the SIP-T46G, T42G and T41P IP phones. The following related
documents for SIP-T4X IP phones are available:
Quick Installation Guides, which describe how to assemble IP phones.
Quick Reference Guides, which describe the most basic features available on IP
phones.
User Guides, which describe basic and advanced features available on IP phones.
Auto Provisioning Deployment Guide, which describes how to provision IP phones
using the configuration files.
Configuration Conversion Tool User Guide, which describes how to convert and
encrypt the configuration files using the Configuration Conversion Tool.
<y0000000000xx>.cfg and <MAC>.cfg template configuration files.
IP Phones Deployment Guide for BroadWorks Environments, which describes how
to configure the BroadSoft features on the BroadWorks web portal and IP phones.
For support or service, please contact your Yealink reseller or go to Yealink Technical
Support online http://www.yealink.com/Support.aspx.
The information detailed in this guide is applicable to the firmware version 71 or higher.
The firmware format likes x.x.x.x.rom. The second x from left should be greater than or
equal to 71(e.g., the firmware version of SIP-T46G IP phone: [phone].rom). This
administrator guide includes the following chapters:
Chapter 1, “Product Overview”describes SIP components and SIP IP phones.
Chapter 2, “Getting Started”describes how to install and connect IP phones and
configuration methods.

Administrator’s Guide for SIP-T4X IP Phones
vi
Chapter 3, “Configuring Basic Features”describes how to configure basic features
on IP phones.
Chapter 4, “Configuring Advanced Features”describes how to configure
advanced features on IP phones.
Chapter 5, “Configuring Audio Features”describes how to configure audio features
on IP phones.
Chapter 6, “Configuring Security Features”describes how to configure security
features on IP phones.
Chapter 7, “Upgrading Firmware”describes how to upgrade the firmware of IP
phones.
Chapter 8, “Resource Files”describes the resource files that can be downloaded
by IP phones.
Chapter 9, “Troubleshooting”describes how to troubleshoot IP phones and
provides some common troubleshooting solutions.
Chapter 10, “Appendix”provides the glossary, reference information about IP
phones compliant with RFC 3261, SIP call flows and sample configuration files.
This section describes the changes to this guide for each release and guide version.
Major updates have occurred to the following sections:
Backlight on page 36
Language on page 47
Logo Customization on page 50
Anonymous Call on page 69
Action URL on page 147
Action URI on page 150
SNMP on page 171
Audio Codecs on page 185
Major updates have occurred to the following sections:
Language on page 47

About This Guide
vii
Auto Answer on page 66
SNMP on page 171
Audio Codecs on page 185
Encrypting Configuration Files on page 203
This version is updated to incorporate T41P as one of the T4X device models. The
following section is new for this version:
Logo Customization on page 50
Major updates have occurred to the following sections:
SIP IP Phone Models on page 3
Configuring Transmission Methods of the Internet Port and PC Port on page 23
Language on page 47
Remote Phone Book on page 123
Server Redundancy on page 153
Audio Codecs on page 185
Transport Layer Security on page 195
Secure Real-Time Transport Protocol on page 201
This version is updated to incorporate T42G as one of the T4X device models. The
following section is new for this version:
SIP IP Phone Models on page 3
Major updates have occurred to the following sections:
Reading Icons on page 15
PPPoE on page 22
Backlight on page 36
Language on page 47
Call Completion on page 68
SNMP on page 171
TR-069 Device Management on page 177
IPv6 Support on page 179
Audio Codecs on page 185

Administrator’s Guide for SIP-T4X IP Phones
viii
Upgrading Firmware on page 207
Configuring DSS Key on page 358

Table of Contents
ix
About This Guide...................................................................v
Documentations...............................................................................................................................v
In This Guide ....................................................................................................................................v
Summary of Changes .................................................................................................................... vi
Changes for Release 71.0, Guide Version 71.171................................................................. vi
Changes for Release 71.0, Guide Version 71.170................................................................. vi
Changes for Release 71.0, Guide Version 71.150................................................................ vii
Changes for Release 71.0, Guide Version 71.80.................................................................. vii
Table of Contents .................................................................ix
Product Overview..................................................................1
VoIP Principle....................................................................................................................................1
SIP Components...............................................................................................................................2
SIP IP Phone Models........................................................................................................................3
Physical Features of SIP-T4X IP Phones ...................................................................................4
Key Features of SIP-T4X IP Phones...........................................................................................6
Getting Started .....................................................................9
Connecting the IP Phone.................................................................................................................9
Initialization Process Overview ....................................................................................................11
Verifying Startup ............................................................................................................................13
Configuration Methods.................................................................................................................13
Phone User Interface..............................................................................................................13
Web User Interface ................................................................................................................14
Configuration Files..................................................................................................................14
Reading Icons ................................................................................................................................15
Configuring Basic Network Parameters ......................................................................................17
DHCP .......................................................................................................................................17
Configuring Network Parameters Manually ........................................................................19
PPPoE........................................................................................................................................22
Configuring Transmission Methods of the Internet Port and PC Port .................................23
Creating Dial Plan..........................................................................................................................25
Replace Rule ...........................................................................................................................26
Dial-now ..................................................................................................................................28
Area Code...............................................................................................................................30

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x
Block Out .................................................................................................................................31
Configuring Basic Features..................................................33
Wallpaper.......................................................................................................................................34
Backlight.........................................................................................................................................36
User Password................................................................................................................................38
Administrator Password................................................................................................................39
Phone Lock .....................................................................................................................................40
Time and Date ...............................................................................................................................42
Language .......................................................................................................................................47
Loading Language Packs ......................................................................................................48
Specifying the Language to Use...........................................................................................48
Logo Customization .......................................................................................................................50
Softkey Layout................................................................................................................................51
Key as Send ...................................................................................................................................54
Hotline ............................................................................................................................................56
Call Log...........................................................................................................................................58
Missed Call Log .............................................................................................................................59
Local Directory ...............................................................................................................................60
Live Dialpad...................................................................................................................................63
Call Waiting....................................................................................................................................63
Auto Redial .....................................................................................................................................65
Auto Answer...................................................................................................................................66
Call Completion.............................................................................................................................68
Anonymous Call.............................................................................................................................69
Anonymous Call Rejection ............................................................................................................71
Do Not Disturb................................................................................................................................73
Busy Tone Delay.............................................................................................................................77
Return Code When Refuse ............................................................................................................78
Early Media....................................................................................................................................79
180 Ring Workaround ....................................................................................................................79
Use Outbound Proxy in Dialog.....................................................................................................80
SIP Session Timer ...........................................................................................................................81
Session Timer .................................................................................................................................82
Call Hold.........................................................................................................................................84
Call Forward ..................................................................................................................................86
Call Transfer ...................................................................................................................................91
Network Conference .....................................................................................................................92
Transfer on Conference Hang Up ................................................................................................93
Directed Call Pickup ......................................................................................................................94
Group Call Pickup..........................................................................................................................97
Dialog-Info Call Pickup................................................................................................................100
Call Return ....................................................................................................................................102
Call Park........................................................................................................................................103

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Web Server Type..........................................................................................................................104
Calling Line Identification Presentation.....................................................................................106
Connected Line Identification Presentation ..............................................................................107
DTMF.............................................................................................................................................108
Suppress DTMF Display ..............................................................................................................111
Transfer via DTMF........................................................................................................................112
Intercom........................................................................................................................................113
Outgoing Intercom Calls......................................................................................................113
Incoming Intercom Calls ......................................................................................................114
Configuring Advanced Features........................................117
Distinctive Ring Tones ..................................................................................................................117
Tones .............................................................................................................................................121
Remote Phone Book ....................................................................................................................123
LDAP..............................................................................................................................................125
Busy Lamp Field...........................................................................................................................128
Music on Hold ..............................................................................................................................131
Automatic Call Distribution .........................................................................................................133
Message Waiting Indicator ........................................................................................................135
Multicast Paging ..........................................................................................................................137
Sending RTP Stream.............................................................................................................137
Receiving RTP Stream ..........................................................................................................139
Call Recording..............................................................................................................................142
Hot Desking..................................................................................................................................145
Action URL ....................................................................................................................................147
Action URI .....................................................................................................................................150
Server Redundancy.....................................................................................................................153
LLDP...............................................................................................................................................158
VLAN .............................................................................................................................................161
VPN................................................................................................................................................164
Quality of Service ........................................................................................................................166
Network Address Translation .....................................................................................................169
SNMP ............................................................................................................................................171
802.1X Authentication..................................................................................................................173
TR-069 Device Management ......................................................................................................177
IPv6 Support .................................................................................................................................179
Configuring Audio Features............................................... 183
Headset Prior ...............................................................................................................................183
Dual Headset...............................................................................................................................184
Audio Codecs ..............................................................................................................................185
Acoustic Clarity Technology........................................................................................................189
Acoustic Echo Cancellation .................................................................................................189

Administrator’s Guide for SIP-T4X IP Phones
xii
Voice Activity Detection .......................................................................................................190
Comfort Noise Generation ..................................................................................................191
Jitter Buffer ............................................................................................................................192
Configuring Security Features............................................ 195
Transport Layer Security..............................................................................................................195
Secure Real-Time Transport Protocol..........................................................................................201
Encrypting Configuration Files ...................................................................................................203
Upgrading Firmware......................................................... 207
Resource Files....................................................................211
Replace Rule Template ...............................................................................................................211
Dial-now Template.......................................................................................................................212
Softkey Layout Template.............................................................................................................213
Local Contact File ........................................................................................................................215
Remote XML Phone Book............................................................................................................216
Specifying the Access URL of Resource Files ............................................................................218
Troubleshooting................................................................. 219
Troubleshooting Methods ...........................................................................................................219
Viewing Log Files..................................................................................................................219
Capturing Packets ................................................................................................................222
Enabling the Watch Dog Feature........................................................................................222
Getting Information from Status Indicators........................................................................223
Analyzing Configuration Files..............................................................................................223
Troubleshooting Solutions ...........................................................................................................224
Why is the LCD screen blank? .............................................................................................224
Why doesn’t the IP phone get an IP address?...................................................................224
How do I find the basic information of the IP phone?.......................................................225
Why doesn’t the IP phone upgrade firmware successfully?.............................................225
Why doesn’t the IP phone display time and date correctly? ...........................................225
Why do I get poor sound quality during a call? ................................................................225
What is the difference between a remote phone book and a local phonebook? ........226
What is the difference between user name, register name and display name? ..........226
How to reboot IP phone remotely?.....................................................................................226
How to increase or decrease the volume?........................................................................226
What will happen if I connect both PoE cable and power adapter? Which has the higher
priority?..................................................................................................................................227
What is auto provisioning? ..................................................................................................227
What is PnP? ..........................................................................................................................227
Why doesn’t the IP phone update the configuration?.......................................................227

Table of Contents
xiii
What do “on code” and “off code” mean?........................................................................227
How to solve the IP conflict problem? ................................................................................228
How to reset your phone to factory configurations?.........................................................228
How to restore the administrator password? ....................................................................228
Appendix .......................................................................... 229
Appendix A: Glossary.................................................................................................................229
Appendix B: Time Zones.............................................................................................................231
Appendix C: Configuration Parameters ....................................................................................234
Setting Parameters in Configuration Files..........................................................................234
Basic and Advanced Feature Parameters.........................................................................234
Audio Feature Parameters...................................................................................................338
Upgrading Firmware............................................................................................................350
Resource Files .......................................................................................................................352
Troubleshooting ....................................................................................................................356
Configuring DSS Key ............................................................................................................358
Appendix D: SIP (Session Initiation Protocol)............................................................................373
RFC and Internet Draft Support ..........................................................................................373
SIP Request............................................................................................................................374
SIP Header ............................................................................................................................375
SIP Responses .......................................................................................................................376
SIP Session Description Protocol (SDP) Usage ..................................................................379
Appendix E: SIP Call Flows .........................................................................................................380
Successful Call Setup and Disconnect ...............................................................................381
Unsuccessful Call Setup—Called User is Busy ..................................................................383
Unsuccessful Call Setup—Called User Does Not Answer ................................................387
Successful Call Setup and Call Hold ..................................................................................390
Successful Call Setup and Call Waiting .............................................................................392
Call Transfer without Consultation ......................................................................................397
Call Transfer with Consultation............................................................................................401
Always Call Forward............................................................................................................407
Busy Call Forward ................................................................................................................410
No Answer Call Forward .....................................................................................................413
Call Conference....................................................................................................................416
Appendix F: Sample Configuration File ....................................................................................421
Index................................................................................. 427

Administrator’s Guide for SIP-T4X IP Phones
xiv

Product Overview
1
This chapter contains the following information about SIP-T4X IP phones:
VoIP Principle
SIP Components
SIP IP Phone Models
VoIP
VoIP (Voice over Internet Protocol) is a technology using the Internet Protocol instead of
traditional Public Switch Telephone Network (PSTN) technology for voice
communications.
It is a family of technologies, methodologies, communication protocols, and
transmission techniques for the delivery of voice communications and multimedia
sessions over IP networks. The H.323 and Session Initiation Protocol (SIP) are two
popular VoIP protocols that are found in widespread implement.
H.323
H.323 is a recommendation from the ITU Telecommunication Standardization Sector
(ITU-T) that defines the protocols to provide audio-visual communication sessions on
any packet network. The H.323 standard addresses call signaling and control,
multimedia transport and control, and bandwidth control for point-to-point and
multi-point conferences.
It is widely implemented by voice and video conference equipment manufacturers, is
used within various Internet real-time applications such as GnuGK and NetMeeting and
is widely deployed worldwide by service providers and enterprises for both voice and
video services over IP networks.
SIP
SIP (Session Initiation Protocol) is the Internet Engineering Task Force’s (IETF’s) standard
for multimedia conferencing over IP. It is an ASCII-based, application-layer control
protocol (defined in RFC 3261) that can be used to establish, maintain, and terminate
calls between two or more endpoints. Like other VoIP protocols, SIP is designed to
address the functions of signaling and session management within a packet telephony
network. Signaling allows call information to be carried across network boundaries.
Session management provides the ability to control the attributes of an end-to-end call.

Administrator’s Guide for SIP-T4X IP Phones
2
SIP provides capabilities to:
Determine the location of the target endpoint -- SIP supports address resolution,
name mapping, and call redirection.
Determine the media capabilities of the target endpoint -- Via Session Description
Protocol (SDP), SIP determines the “lowest level” of common services between
endpoints. Conferences are established using only the media capabilities that can
be supported by all endpoints.
Determine the availability of the target endpoint -- A call cannot be completed
because the target endpoint is unavailable. SIP determines whether the called
party is already on the IP phone or did not answer in the allotted number of rings. It
then returns a message indicating why the target endpoint was unavailable.
Establish a session between the origin and target endpoint -- The call can be
completed, SIP establishes a session between endpoints. SIP also supports mid-call
changes, such as the addition of another endpoint to the conference or the
changing of a media characteristic or codec.
Handle the transfer and termination of calls -- SIP supports the transfer of calls from
one endpoint to another. During a call transfer, SIP simply establishes a session
between the transferee and a new endpoint (specified by the transferring party)
and terminates the session between the transferee and the transferring party. At
the end of a call, SIP terminates the sessions between all parties.
SIP is a peer-to-peer protocol. The peers in a session are called User Agents (UAs). A
user agent can function as one of the following roles:
User Agent Client (UAC) -- A client application that initiates the SIP request.
User Agent Server (UAS) -- A server application that contacts the user when a SIP
request is received and that returns a response on behalf of the user.
User Agent Client (UAC)
The UAC is an application that initiates up to six feasible SIP requests to the UAS. The six
requests issued by the UAC are: INVITE, ACK, OPTIONS, BYE, CANCEL and REGISTER.
When the SIP session is being initiated by the UAC SIP component, the UAC determines
the information essential for the request, which is the protocol, the port and the IP
address of the UAS to which the request is being sent. This information can be dynamic
and this will make it challenging to put through a firewall. For this reason it may be
recommended to open the specific application type on the firewall. The UAC is also
capable of using the information in the request URI to establish the course of the SIP
request to its destination, as the request URI always specifies the host which is essential.
The port and protocol are not always specified by the request URI. Thus if the request
does not specify a port or protocol, a default port or protocol is contacted. Using this

Product Overview
3
method may be the preferred measure when not using an application layer firewall,
application layer firewalls like to know what applications are flowing though which
ports and it is possible using content types of other applications other than the one you
are trying to let through which has been denied.
User agent server (UAS)
UAS is the server that hosts the application responsible for receiving the SIP requests
from a UAC, and on reception returns a response to the request back to the UAC. The
UAS may issue multiple responses to the UAC, not necessarily a single response.
Communication between UAC and UAS is client/server and peer-to–peer.
Typically, a SIP endpoint is capable of functioning as both a UAC and a UAS, but it
functions only as one or the other per transaction. Whether the endpoint functions as a
UAC or a UAS depends on the UA that initiates the request.
This section introduces the SIP-T4X IP phone family. SIP-T4X IP phones are endpoints in
the overall network topology, which are designed to interoperate with other compatible
equipments including application servers, media servers, internet-working gateways,
voice bridges, and other endpoints. SIP-T4X IP phones are characterized by a large
number of functions, which simplify business communication with a high standard of
security and can work seamlessly with a large number of SIP PBXs.
SIP-T4X IP phones provide a powerful and flexible IP communication solution for Ethernet
TCP/IP networks, delivering excellent voice quality. The high-resolution graphic display
supplies content in multiple languages for system status, call history and directory
access. SIP-T4X IP phones also support advanced functionalities, including LDAP, Busy
Lamp Field, Sever Redundancy and Network Conference.
The following IP phone models are described:
SIP-T46G
SIP-T42G
SIP-T41P
SIP-T4X IP phones comply with the SIP standard (RFC 3261), and they can only be used
within a network that supports this type of phone.
For successfully operating as SIP endpoints in your network, SIP-T4X IP phones must meet
the following requirements:
A working IP network is established.
Routers are configured for VoIP.
VoIP gateways are configured for SIP.
The latest (or compatible) firmware of SIP-T4X IP phones is available.

Administrator’s Guide for SIP-T4X IP Phones
4
A call server is active and configured to receive and send SIP messages.
This section lists the available physical features of SIP-T4X IP phones.
SIP-T46G
Physical Features:
-4.3” TFT-LCD, 480 x 272 pixel, 16.7M colors
-6 VoIP accounts, BroadSoft/Avaya/Asterisk validated
-HD Voice: HD Codec, HD Handset, HD Speaker
-41 keys including 10 line keys
-1xRJ9 (4P4C) handset port
-1xRJ9 (4P4C) headset port
-2xRJ45 10/100/1000M Ethernet ports
-1XRJ12 (6P6C) expansion module port
-14 LEDs: 1xpower, 10xline, 1xmute, 1xheadset, 1xspeakerphone
-Power adapter: AC 100~240V input and DC 5V/2A output
-Power over Ethernet (IEEE 802.3af)
-Built-in USB port, support Bluetooth headset

Product Overview
5
SIP-T42G
Physical Features:
-192 x 64 graphic LCD
-3 VoIP accounts, BroadSoft/Avaya/Asterisk validated
-HD Voice: HD Codec, HD Handset, HD Speaker
-35 keys including 6 line keys
-1xRJ9 (4P4C) handset port
-1xRJ9 (4P4C) headset port
-2xRJ45 10/100/1000M Ethernet ports
-1XRJ12 (6P6C) EHS36 headset adapter port
-10 LEDs: 1xpower, 6xline, 1xmute, 1xheadset, 1xspeakerphone
-Power adapter: AC 100~240V input and DC 5V/1.2A output
-Power over Ethernet (IEEE 802.3af)

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6
SIP-T41P
Physical Features:
-192 x 64 graphic LCD
-3 VoIP accounts, BroadSoft/Avaya/Asterisk validated
-HD Voice: HD Codec, HD Handset, HD Speaker
-35 keys including 6 line keys
-1xRJ9 (4P4C) handset port
-1xRJ9 (4P4C) headset port
-2xRJ45 10/100M Ethernet ports
-1XRJ12 (6P6C) EHS36 headset adapter port
-10 LEDs: 1xpower, 6xline, 1xmute, 1xheadset, 1xspeakerphone
-Power adapter: AC 100~240V input and DC 5V/1.2A output
-Power over Ethernet (IEEE 802.3af)
In addition to physical features introduced above, SIP-T4X IP phones also support the
following key features when running the latest firmware:
Phone Features
-Call Options: emergency call, call waiting, call hold, call mute, call forward,
call transfer, call pickup, 3-way conference.
-Basic Features: DND, phone lock, auto redial, live dialpad, dial plan, hotline,