Yealink SIP-T2 Series Service manual

Copyright © 2014 YEALINK NETWORK TECHNOLOGY
Copyright © 2014 Yealink Network Technology CO., LTD. All rights reserved. No parts of this
publication may be reproduced or transmitted in any form or by any means, electronic or
mechanical, photocopying, recording, or otherwise, for any purpose, without the express written
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its consent to downloading and printing copies of the content provided in this file only for private
use but not for redistribution. No parts of this publication may be subject to alteration,
modification or commercial use. Yealink Network Technology CO., LTD. will not be liable for any
damages arising from use of an illegally modified or altered publication.
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.
YEALINK NETWORK TECHNOLOGY CO., LTD. MAKES NO WARRANTY OF ANY KIND WITH
REGARD TO THIS GUIDE, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Yealink Network Technology
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.
Any Changes or modifications not expressly approved by the party responsible for compliance could void
the user's authority to operate the equipment.

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.
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 [email protected].

Yealink 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 from Yealink web site:
http://www.yealink.com/GPLOpenSource.aspx?BaseInfoCateId=293&NewsCateId=293&CateId=293.

About This Guide
v
This guide is intended for administrators who need to properly configure, customize,
manage, and troubleshoot the IP phone system rather than end-users. It provides
details on the functionality and configuration of IP phones.
Many of the features described in this guide involve network settings, which could affect
the IP phone’s performance in the network. So an understanding of IP networking and a
prior knowledge of IP telephony concepts are necessary.
This guide covers SIP-T23 (P/G) IP phones. The following related documents are
available:
Quick Start Guides, which describe how to assemble IP phones and configure the
most basic features available on IP phones.
User Guides, which describe the basic and advanced features available on IP
phones.
Auto Provisioning Guide, which describes how to provision IP phones using the
configuration files.
<y0000000000xx>.cfg and <MAC>.cfg template configuration files.
IP Phones Deployment Guide for BroadSoft UC-One Environments, which describes
how to configure 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 firmware version 80 or higher. The
firmware format is like x.x.x.x.rom. The second x from left must be greater than or equal
to 80 (e.g., the firmware version of SIP-T23G IP phone: 44.80.0.5.rom). This administrator
guide includes the following chapters:
Chapter 1, “Product Overview” describes the SIP components and SIP IP phones.
Chapter 2, “Getting Started” describes how to install and connect IP phones and
the configuration methods.
Chapter 3, “Configuring Basic Features” describes how to configure the basic
features on IP phones.
Chapter 4, “Configuring Advanced Features” describes how to configure the

Administrator’s Guide for SIP-T23 & T23P & T23G IP Phones
vi
advanced features on IP phones.
Chapter 5, “Configuring Audio Features” describes how to configure the audio
features on IP phones.
Chapter 6, “Configuring Security Features” describes how to configure the security
features on IP phones.
Chapter 7, “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 the sample configuration files.

Table of Contents
vii
About This Guide ...................................................................... v
Documentations...............................................................................................................................v
In This Guide ....................................................................................................................................v
Table of Contents ....................................................................vii
Product Overview..................................................................... 1
VoIP Principle....................................................................................................................................1
SIP Components...............................................................................................................................2
SIP IP Phone Models........................................................................................................................3
Physical Features of IP Phones ................................................................................................4
Key Features of IP Phones........................................................................................................5
Getting Started......................................................................... 7
Connecting the IP Phones ...............................................................................................................7
Initialization Process Overview ....................................................................................................10
Verifying Startup ............................................................................................................................11
Reading Icons ................................................................................................................................11
Configuration Methods.................................................................................................................13
Phone User Interface..............................................................................................................13
Web User Interface ................................................................................................................13
Configuration Files..................................................................................................................13
Provisioning Server........................................................................................................................17
Supported Provisioning Protocols .........................................................................................17
Setting up the Provisioning Server........................................................................................17
Deploying Phones from the Provisioning Server ................................................................. 18
Configuring Basic Network Parameters ......................................................................................19
DHCP .......................................................................................................................................19
Configuring Network Parameters Manually ........................................................................24
PPPoE .......................................................................................................................................30
Configuring Transmission Methods of the Internet Port and PC Port .................................33
Configuring PC Port Mode .....................................................................................................36
Upgrading Firmware.....................................................................................................................38
Configuring Basic Features .................................................... 45

Administrator’s Guide for SIP-T23 & T23P & T23G IP Phones
viii
Power Indicator LED ......................................................................................................................46
Notification Popups........................................................................................................................51
Contrast ..........................................................................................................................................53
Backlight.........................................................................................................................................55
Call Display ....................................................................................................................................56
Web Server Type............................................................................................................................59
User Password ...............................................................................................................................62
Administrator Password ................................................................................................................64
Keypad Lock ..................................................................................................................................66
Time and Date ...............................................................................................................................71
Language .......................................................................................................................................83
Loading Language Packs ......................................................................................................83
Specifying the Language to Use...........................................................................................90
Input Method Customization ........................................................................................................92
Logo Customization.......................................................................................................................97
Softkey Layout..............................................................................................................................100
Key as send..................................................................................................................................106
Dial Plan........................................................................................................................................109
Replace Rule .........................................................................................................................110
Dial-now ................................................................................................................................113
Area Code.............................................................................................................................117
Block Out ...............................................................................................................................120
Hotline ..........................................................................................................................................121
Off Hook Hot Line Dialing...........................................................................................................124
Directory .......................................................................................................................................125
Search Source in Dialing.............................................................................................................127
Call Log.........................................................................................................................................129
Missed Call Log ...........................................................................................................................130
Local Directory.............................................................................................................................132
Live Dialpad................................................................................................................................. 136
Call Waiting..................................................................................................................................138
Auto Redial...................................................................................................................................142
Auto Answer.................................................................................................................................144
Call Completion...........................................................................................................................147
Anonymous Call........................................................................................................................... 149
Anonymous Call Rejection ..........................................................................................................153
Do Not Disturb..............................................................................................................................157
Busy Tone Delay...........................................................................................................................165
Return Code When Refuse ..........................................................................................................167
Early Media..................................................................................................................................168
180 Ring Workaround ..................................................................................................................168
Use Outbound Proxy in Dialog...................................................................................................170
SIP Session Timer .........................................................................................................................172
Session Timer ...............................................................................................................................174

Table of Contents
ix
Call Hold.......................................................................................................................................177
Call Forward ................................................................................................................................181
Call Transfer .................................................................................................................................199
Network Conference ...................................................................................................................202
Feature Key Synchronization......................................................................................................204
Transfer on Conference Hang Up ..............................................................................................206
Directed Call Pickup....................................................................................................................207
Group Call Pickup........................................................................................................................213
Dialog Info Call Pickup................................................................................................................219
Call Return ....................................................................................................................................222
Call Park .......................................................................................................................................224
Calling Line Identification Presentation..................................................................................... 226
Connected Line Identification Presentation ..............................................................................228
DTMF.............................................................................................................................................229
Suppress DTMF Display .............................................................................................................. 235
Transfer via DTMF ........................................................................................................................237
Intercom........................................................................................................................................239
Outgoing Intercom Calls......................................................................................................239
Incoming Intercom Calls ......................................................................................................241
Configuring Advanced Features...........................................245
Distinctive Ring Tones ..................................................................................................................246
Tones .............................................................................................................................................252
Remote Phone Book ....................................................................................................................258
LDAP..............................................................................................................................................262
Busy Lamp Field...........................................................................................................................273
BLF List .......................................................................................................................................... 280
Hide Features Access Code.......................................................................................................284
Automatic Call Distribution .........................................................................................................286
Message Waiting Indicator ........................................................................................................290
Multicast Paging ..........................................................................................................................295
Sending RTP Stream............................................................................................................. 295
Receiving RTP Stream ..........................................................................................................302
Call Recording .............................................................................................................................305
Hot Desking..................................................................................................................................310
Action URL ....................................................................................................................................312
Action URI.....................................................................................................................................328
Capturing the Current Screen of the Phone.......................................................................332
Server Redundancy.....................................................................................................................333
SIP Server Domain Name Resolution..................................................................................340
Static DNS Cache ........................................................................................................................344
LLDP...............................................................................................................................................352
CDP ...............................................................................................................................................356
VLAN .............................................................................................................................................358

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VPN................................................................................................................................................366
Voice Quality Monitoring ............................................................................................................369
Quality of Service ........................................................................................................................369
Network Address Translation .....................................................................................................372
802.1X Authentication .................................................................................................................377
TR-069 Device Management ......................................................................................................388
IPv6 Support ................................................................................................................................. 393
Configuring Audio Features ..................................................402
Headset Prior ...............................................................................................................................402
Dual Headset............................................................................................................................... 403
Audio Codecs ..............................................................................................................................405
Acoustic Clarity Technology........................................................................................................412
Acoustic Echo Cancellation ................................................................................................. 412
Background Noise Suppression..........................................................................................413
Automatic Gain Control .......................................................................................................413
Voice Activity Detection .......................................................................................................413
Comfort Noise Generation ..................................................................................................415
Jitter Buffer ............................................................................................................................416
Configuring Security Features...............................................420
Transport Layer Security.............................................................................................................. 420
Secure Real-Time Transport Protocol..........................................................................................429
Encrypting Configuration Files ...................................................................................................432
Resource Files........................................................................438
Replace Rule Template ...............................................................................................................439
Dial-now Template.......................................................................................................................440
Softkey Layout Template.............................................................................................................441
Directory Template ......................................................................................................................442
Super Search Template...............................................................................................................443
Local Contact File ........................................................................................................................445
Remote XML Phone Book............................................................................................................446
Troubleshooting.....................................................................450
Troubleshooting Methods ...........................................................................................................450
Viewing Log Files..................................................................................................................450
Capturing Packets ................................................................................................................455
Enabling Watch Dog Feature ..............................................................................................456
Getting Information from Status Indicators........................................................................458
Analyzing Configuration File ...............................................................................................458

Table of Contents
xi
Troubleshooting Solutions ...........................................................................................................460
Why is the LCD screen blank? .............................................................................................460
Why doesn’t the IP phone get an IP address? ...................................................................460
Why does the IP phone display “No Service”? .................................................................461
How do I find the basic information of the IP phone?.......................................................461
Why doesn’t the IP phone upgrade firmware successfully?.............................................461
Why doesn’t the IP phone display time and date correctly? ...........................................461
Why do I get poor sound quality during a call? ................................................................461
What is the difference between a remote phone book and a local phone book? .......462
What is the difference among user name, register name and display name? .............462
How to reboot the IP phone remotely? ..............................................................................462
Why does the IP phone use DOB format logo file instead of popular BMP, JPG and so on?
................................................................................................................................................463
How to increase or decrease the volume?........................................................................463
What is auto provisioning? ..................................................................................................463
What is PnP? ..........................................................................................................................463
Why doesn’t the IP phone update the configuration? ......................................................463
What do “on code” and “off code” mean? .......................................................................464
How to solve the IP conflict problem? ................................................................................464
How to reset the IP phone to factory configurations?.......................................................464
How to restore the administrator password? ....................................................................465
Appendix ...............................................................................466
Appendix A: Glossary.................................................................................................................466
Appendix B: Time Zones.............................................................................................................468
Appendix C: Trusted Certificates ...............................................................................................470
Appendix D: Configuring DSS Key.............................................................................................471
Appendix E: SIP (Session Initiation Protocol) ............................................................................479
RFC and Internet Draft Support ..........................................................................................479
SIP Request............................................................................................................................482
SIP Header ............................................................................................................................483
SIP Responses .......................................................................................................................484
SIP Session Description Protocol (SDP) Usage ..................................................................487
Appendix F: SIP Call Flows .........................................................................................................487
Successful Call Setup and Disconnect ...............................................................................488
Unsuccessful Call Setup—Called User is Busy ..................................................................491
Unsuccessful Call Setup—Called User Does Not Answer ................................................493
Successful Call Setup and Call Hold..................................................................................495
Successful Call Setup and Call Waiting .............................................................................498
Call Transfer without Consultation ......................................................................................503
Call Transfer with Consultation............................................................................................507
Always Call Forward............................................................................................................512
Busy Call Forward ................................................................................................................516
No Answer Call Forward .....................................................................................................519

Administrator’s Guide for SIP-T23 & T23P & T23G IP Phones
xii
Call Conference....................................................................................................................522
Index ......................................................................................528

Product Overview
1
This chapter contains the following information about 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 implementation.
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 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 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 attributes of an end-to-end call.

Administrator’s Guide for SIP-T23 & T23P & T23G IP Phones
2
SIP provides capabilities to:
Determine the location of the target endpoint -- SIP supports address resolution,
name mapping, and call redirection.
Determine 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 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 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 SIP IP phone models. 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. 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.
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 log and directory access.
IP phones also support advanced functionalities, including LDAP, Busy Lamp Field, Sever
Redundancy and Network Conference.
The following IP phone models are described:
SIP-T23
SIP-T23P
SIP-T23G
IP phones comply with the SIP standard (RFC 3261), and they can only be used within a
network that supports this model of phone.
For a list of key features available on Yealink IP phones running the latest firmware, refer
to Key Features of IP Phones on page 5.

Administrator’s Guide for SIP-T23 & T23P & T23G IP Phones
4
In order to operate as SIP endpoints in your network successfully, IP phones must meet
the following requirements:
A working IP network is established.
VoIP gateways are configured for SIP.
The latest (or compatible) firmware of IP phones is available.
A call server is active and configured to receive and send SIP messages.
This section lists the available physical features of IP phones.
SIP-T23 (P/G)
Physical Features:
-TI TITAN chipset and TI voice engine
-132x64 graphic LCD with 4-level grayscales
-3 VoIP accounts, BroadSoft/Avaya/Asterisk validated
-HD Voice: HD Codec, HD Handset, HD Speaker
-32 keys including 4 soft keys
-1xRJ9 (4P4C) handset port
-1xRJ9 (4P4C) headset port
-2xRJ45 10/100/1000Mbps Ethernet ports (1000Mbps is only applicable to SIP-T23G IP
phones)
-5 LEDs: 1xpower, 3xline, 1xmessage
-Power adapter: AC 100~240V input and DC 5V/1.2A output
-Power over Ethernet (IEEE 802.3af) (not applicable to SIP-T23 IP phones)
-Wall Mount

Product Overview
5
In addition to physical features introduced above, 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,
caller identity, auto answer.
-Advanced Features: BLF, server redundancy, distinctive ring tones, remote
phone book, LDAP, 802.1X authentication.
Codecs and Voice Features
-Wideband codec: G.722
-Narrowband codec: G.711, G.726, G.729, iLBC
-VAD, CNG, AEC, PLC, AJB, AGC
-Full-duplex speakerphone with AEC
Network Features
-SIP v1 (RFC2543), v2 (RFC3261)
-NAT Traversal: STUN mode
-DTMF: INBAND, RFC2833, SIP INFO
-Proxy mode and peer-to-peer SIP link mode
-IP assignment: Static/DHCP/PPPoE
-VLAN assignment: LLDP/Static/DHCP/CDP
-Bridge mode for PC port
-TFTP/DHCP/PPPoE client
-HTTP/HTTPS server
-DNS client
-NAT/DHCP server
-IPv6 support
Management
-FTP/TFTP/HTTP/PnP auto-provision
-Configuration: browser/phone/auto-provision
-Direct IP call without SIP proxy
-Dial number via SIP server
-Dial URL via SIP server
-TR-069
Security
-HTTPS (server/client)

Administrator’s Guide for SIP-T23 & T23P & T23G IP Phones
6
-SRTP (RFC3711)
-Transport Layer Security (TLS)
-VLAN (802.1q), QoS
-Digest authentication using MD5/MD5-sess
-Secure configuration file via AES encryption
-Phone lock for personal privacy protection
-Admin/User configuration mode

Getting Started
7
This chapter provides basic information and installation instructions of IP phones.
This chapter provides the following sections:
Connecting the IP Phones
Initialization Process Overview
Verifying Startup
Reading Icons
Configuration Methods
Provisioning Server
Configuring Basic Network Parameters
Upgrading Firmware
This section introduces how to install IP phones with components in packaging contents.
1. Attach the stand
2. Connect the handset and optional headset
3. Connect the network and power
Note
A headset is not included in packaging contents.

Administrator’s Guide for SIP-T23 & T23P & T23G IP Phones
8
1) Attach the stand:
2) Connect the handset and optional headset:
3) Connect the network and power:
AC power (Optional)
Power over Ethernet (PoE)
Note
AC Power (Optional)
To connect the AC power and network:
1. Connect the DC plug of the power adapter to the DC5V port on the IP phone and
connect the other end of the power adapter into an electrical power outlet.
PoE is not applicable to the SIP-T23 IP phone. A power adapter should be purchased
separately to power it on.