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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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 phone firmware contains 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 BroadSoft UC-One 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 is like 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 section:
Language on page 49
Major updates have occurred to the following sections:
Language on page 49
Anonymous Call on page 72
SNMP on page 173
Major updates have occurred to the following sections:
Backlight on page 38
Language on page 49

About This Guide
vii
Logo Customization on page 52
Anonymous Call on page 72
Action URL on page 149
Action URI on page 152
SNMP on page 173
Audio Codecs on page 189
Major updates have occurred to the following sections:
Language on page 49
Auto Answer on page 68
SNMP on page 173
Audio Codecs on page 189
Encrypting Configuration Files on page 207
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 52
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 24
Language on page 49
Remote Phone Book on page 125
Server Redundancy on page 155
Audio Codecs on page 189
Transport Layer Security on page 199
Secure Real-Time Transport Protocol on page 205
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

Administrator’s Guide for SIP-T4X IP Phones
viii
Major updates have occurred to the following sections:
Reading Icons on page 16
PPPoE on page 23
Backlight on page 38
Language on page 49
Call Completion on page 70
SNMP on page 173
TR-069 Device Management on page 180
IPv6 Support on page 182
Audio Codecs on page 189
Upgrading Firmware on page 211
Configuring DSS Key on page 362

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 71.181................................................................. vi
Changes for Release 71.0, Guide Version 71.180................................................................. vi
Changes for Release 71.0, Guide Version 71.171................................................................. vi
Changes for Release 71.0, Guide Version 71.170................................................................ vii
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 ....................................................................................................12
Verifying Startup ............................................................................................................................14
Configuration Methods.................................................................................................................14
Phone User Interface..............................................................................................................14
Web User Interface ................................................................................................................14
Configuration Files..................................................................................................................15
Reading Icons ................................................................................................................................16
Configuring Basic Network Parameters ......................................................................................18
DHCP .......................................................................................................................................18
Configuring Network Parameters Manually ........................................................................20
PPPoE........................................................................................................................................23
Configuring Transmission Methods of the Internet Port and PC Port .................................24
Creating Dial Plan..........................................................................................................................26
Replace Rule ...........................................................................................................................27

Administrator’s Guide for SIP-T4X IP Phones
x
Dial-now ..................................................................................................................................29
Area Code...............................................................................................................................31
Block Out .................................................................................................................................32
Configuring Basic Features..................................................35
Wallpaper.......................................................................................................................................36
Backlight.........................................................................................................................................38
User Password................................................................................................................................40
Administrator Password ................................................................................................................41
Phone Lock .....................................................................................................................................42
Time and Date ...............................................................................................................................44
Language .......................................................................................................................................49
Loading Language Packs ......................................................................................................50
Specifying the Language to Use...........................................................................................51
Logo Customization .......................................................................................................................52
Softkey Layout................................................................................................................................53
Key as Send ...................................................................................................................................56
Hotline ............................................................................................................................................58
Call Log...........................................................................................................................................60
Missed Call Log .............................................................................................................................61
Local Directory ...............................................................................................................................62
Live Dialpad...................................................................................................................................65
Call Waiting....................................................................................................................................65
Auto Redial .....................................................................................................................................67
Auto Answer...................................................................................................................................68
Call Completion.............................................................................................................................70
Anonymous Call.............................................................................................................................72
Anonymous Call Rejection ............................................................................................................73
Do Not Disturb................................................................................................................................75
Busy Tone Delay.............................................................................................................................79
Return Code When Refuse ............................................................................................................80
Early Media....................................................................................................................................81
180 Ring Workaround ....................................................................................................................81
Use Outbound Proxy in Dialog.....................................................................................................82
SIP Session Timer ...........................................................................................................................83
Session Timer .................................................................................................................................84
Call Hold.........................................................................................................................................86
Call Forward ..................................................................................................................................88
Call Transfer ...................................................................................................................................93
Network Conference .....................................................................................................................94
Transfer on Conference Hang Up ................................................................................................95
Directed Call Pickup ......................................................................................................................96
Group Call Pickup..........................................................................................................................99
Dialog-Info Call Pickup................................................................................................................102

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xi
Call Return ....................................................................................................................................104
Call Park........................................................................................................................................105
Web Server Type..........................................................................................................................106
Calling Line Identification Presentation.....................................................................................108
Connected Line Identification Presentation ..............................................................................109
DTMF.............................................................................................................................................110
Suppress DTMF Display ..............................................................................................................113
Transfer via DTMF........................................................................................................................114
Intercom........................................................................................................................................115
Outgoing Intercom Calls......................................................................................................115
Incoming Intercom Calls ......................................................................................................116
Configuring Advanced Features........................................119
Distinctive Ring Tones ..................................................................................................................119
Tones .............................................................................................................................................123
Remote Phone Book ....................................................................................................................125
LDAP..............................................................................................................................................127
Busy Lamp Field...........................................................................................................................130
Music on Hold ..............................................................................................................................133
Automatic Call Distribution .........................................................................................................135
Message Waiting Indicator ........................................................................................................137
Multicast Paging ..........................................................................................................................139
Sending RTP Stream.............................................................................................................139
Receiving RTP Stream ..........................................................................................................141
Call Recording..............................................................................................................................144
Hot Desking..................................................................................................................................147
Action URL ....................................................................................................................................149
Action URI .....................................................................................................................................152
Server Redundancy.....................................................................................................................155
SIP Server Domain Name Resolution..................................................................................156
LLDP...............................................................................................................................................160
VLAN .............................................................................................................................................163
VPN................................................................................................................................................166
Quality of Service ........................................................................................................................168
Network Address Translation .....................................................................................................171
SNMP ............................................................................................................................................173
802.1X Authentication..................................................................................................................175
TR-069 Device Management ......................................................................................................180
IPv6 Support .................................................................................................................................182
Configuring Audio Features............................................... 187
Headset Prior ...............................................................................................................................187
Dual Headset...............................................................................................................................188

Administrator’s Guide for SIP-T4X IP Phones
xii
Audio Codecs ..............................................................................................................................189
Acoustic Clarity Technology........................................................................................................193
Acoustic Echo Cancellation .................................................................................................193
Voice Activity Detection .......................................................................................................194
Comfort Noise Generation ..................................................................................................195
Jitter Buffer ............................................................................................................................196
Configuring Security Features............................................ 199
Transport Layer Security..............................................................................................................199
Secure Real-Time Transport Protocol..........................................................................................205
Encrypting Configuration Files ...................................................................................................207
Upgrading Firmware......................................................... 211
Resource Files.................................................................... 215
Replace Rule Template ...............................................................................................................215
Dial-now Template.......................................................................................................................216
Softkey Layout Template.............................................................................................................217
Local Contact File ........................................................................................................................219
Remote XML Phone Book............................................................................................................220
Specifying the Access URL of Resource Files ............................................................................222
Troubleshooting................................................................. 223
Troubleshooting Methods ...........................................................................................................223
Viewing Log Files..................................................................................................................223
Capturing Packets ................................................................................................................226
Enabling the Watch Dog Feature........................................................................................226
Getting Information from Status Indicators........................................................................227
Analyzing Configuration Files..............................................................................................227
Troubleshooting Solutions ...........................................................................................................228
Why is the LCD screen blank? .............................................................................................228
Why doesn’t the IP phone get an IP address?...................................................................228
How do I find the basic information of the IP phone?.......................................................229
Why doesn’t the IP phone upgrade firmware successfully?.............................................229
Why doesn’t the IP phone display time and date correctly? ...........................................229
Why do I get poor sound quality during a call? ................................................................229
What is the difference between a remote phone book and a local phonebook? ........230
What is the difference between user name, register name and display name? ..........230
How to reboot IP phone remotely?.....................................................................................230
How to increase or decrease the volume?........................................................................230
What will happen if I connect both PoE cable and power adapter? Which has the higher
priority?..................................................................................................................................231

Table of Contents
xiii
What is auto provisioning? ..................................................................................................231
What is PnP? ..........................................................................................................................231
Why doesn’t the IP phone update the configuration?.......................................................231
What do ―on code‖ and ―off code‖ mean?........................................................................231
How to solve the IP conflict problem? ................................................................................232
How to reset your phone to factory configurations?.........................................................232
How to restore the administrator password? ....................................................................232
Appendix .......................................................................... 233
Appendix A: Glossary.................................................................................................................233
Appendix B: Time Zones.............................................................................................................235
Appendix C: Configuration Parameters ....................................................................................238
Setting Parameters in Configuration Files..........................................................................238
Basic and Advanced Feature Parameters.........................................................................238
Audio Feature Parameters...................................................................................................342
Upgrading Firmware............................................................................................................354
Resource Files .......................................................................................................................356
Troubleshooting ....................................................................................................................360
Configuring DSS Key ............................................................................................................362
Appendix D: SIP (Session Initiation Protocol)............................................................................377
RFC and Internet Draft Support ..........................................................................................377
SIP Request............................................................................................................................378
SIP Header ............................................................................................................................379
SIP Responses .......................................................................................................................380
SIP Session Description Protocol (SDP) Usage ..................................................................383
Appendix E: SIP Call Flows .........................................................................................................384
Successful Call Setup and Disconnect ...............................................................................385
Unsuccessful Call Setup—Called User is Busy ..................................................................387
Unsuccessful Call Setup—Called User Does Not Answer ................................................391
Successful Call Setup and Call Hold ..................................................................................394
Successful Call Setup and Call Waiting .............................................................................396
Call Transfer without Consultation ......................................................................................401
Call Transfer with Consultation............................................................................................405
Always Call Forward............................................................................................................411
Busy Call Forward ................................................................................................................414
No Answer Call Forward .....................................................................................................417
Call Conference....................................................................................................................420
Appendix F: Sample Configuration File ....................................................................................425
Index................................................................................. 431

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 does not answer in the allotted number of rings.
It then returns a message indicating why the target endpoint is 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 change
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 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. It may be

Product Overview
3
preferential to use this method when not using an application layer firewall. Application
layer firewalls like to know what applications are flowing though which ports and it is
possible to use content types of other applications other than the one you are trying to
let through what has been denied.
User agent server (UAS)
UAS is a server that hosts the application responsible for receiving the SIP requests from
a UAC, and on reception it 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.
In order to operate as SIP endpoints in your network successfully, 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)

Administrator’s Guide for SIP-T4X IP Phones
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, conference.
-Basic Features: DND, phone lock, auto redial, live dialpad, dial plan, hotline,