Yealink SIP-T2XP Service manual

Copyright © 2014 YEALINK NETWORK TECHNOLOGY
Copyright © 2014 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.
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
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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 [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-T28P, SIP-T26P, SIP-T22P, SIP-T21P, SIP-T20P and SIP-T19P IP phones. The
following related documents 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 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 72 or higher. The
firmware format is like x.x.x.x.rom. The second x from left must be greater than or equal
to 72 (e.g., the firmware version of SIP-T28P IP phone: 2.72.0.1.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.

Administrator’s Guide for SIP-T2xP and SIP-T19P IP Phones
vi
Chapter 4, “Configuring Advanced Features” describes how to configure the
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, “Upgrading Firmware” describes how to upgrade 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 the sample configuration files.
This section describes the changes to this guide for each release and guide version. For
more information on changes, refer to version-specific release notes of Yealink IP
phones online:
http://www.yealink.com/DocumentDownload.aspx?CateId=142&flag=142.
The following section is new for this version:
Directory on page 75
Search Source in Dialing on page 77
Major updates have occurred to the following sections:
Transport Layer Security on page 223
The following section is new for this version:
Power Indicator LED on page 38
Major updates have occurred to the following sections:
DHCP on page 22
Replace Rule on page 68
Dial-now on page 69

About This Guide
vii
Contrast on page 40
Backlight on page 42
Time and Date on page 50
Key as Send on page 65
Anonymous Call on page 91
LDAP on page 150
Busy Lamp Field on page 153
Action URL on page 173
IPv6 Support on page 206
Transport Layer Security on page 223
Upgrading Firmware on page 34
Resource Files on page 238
Documentations of the newly released SIP-T19P and SIP-T21P IP phones have also been
added.
Major updates have occurred to the following sections:
Action URL on page 173
Action URI on page 176
Major updates have occurred to the following sections:
Logo Customization on page 59
Anonymous Call on page 91
Distinctive Ring Tones on page 141
Server Redundancy on page 179
Transport Layer Security on page 223
Secure Real-Time Transport Protocol on page 229
Encrypting Configuration Files on page 232
Local Contact File on page 244
Viewing Log Files on page 250

Administrator’s Guide for SIP-T2xP and SIP-T19P IP Phones
viii
Capturing Packets on page 253
Major updates have occurred to the following section:
Appendix B: Time Zones on page 266
Major updates have occurred to the following section:
Configuring DSS Key on page 410
The following sections are new for this version:
Hot Desking on page 172
TR-069 Device Management on page 204
IPv6 Support on page 206
Major updates have occurred to the following sections:
Configuring Network Parameters Manually on page 25
Softkey Layout on page 62
Directed Call Pickup on page 119
Distinctive Ring Tones on page 141
Automatic Call Distribution on page 159
Action URL on page 176
Server Redundancy on page 179
VLAN on page 189
Transport Layer Security on page 223
Local Contact File on page 244
The following sections are new for this version:
Configuring Network Parameters Manually on page 25
Contrast on page 40
Backlight on page 42

About This Guide
ix
Logo Customization on page 59
Softkey Layout on page 62
Key as Send on page 65
Call Log on page 78
Live Dialpad on page 84
Auto Answer on page 88
Call Completion on page 90
Anonymous Call on page 91
Anonymous Call Rejection on page 93
Busy Tone Delay on page 99
Return Code When Refuse on page 100
Early Media on page 101
180 Ring Workaround on page 101
Use Outbound Proxy in Dialog on page 103
SIP Session Timer on page 104
Session Timer on page 105
Call Return on page 127
Transfer via DTMF on page 136
Intercom on page 137
Automatic Call Distribution on page 159
Message Waiting Indicator on page 162
Multicast Paging on page 164
Call Recording on page 168
LLDP on page 186
VLAN on page 189
VPN on page 192
Quality of Service on page 195
Configuring Audio Features on page 211
Secure Real-Time Transport Protocol on page 229
Appendix B: Time Zones on page 266
Phone user interface for each feature

Administrator’s Guide for SIP-T2xP and SIP-T19P IP Phones
x
Major updates have occurred to the following sections:
Dial Plan on page 67
Transport Layer Security on page 223
Encrypting Configuration Files on page 232
Troubleshooting on page 250
Web user interface for each feature
The following sections are new for this version:
Dialog Info Call Pickup on page 125
Web Server Type on page 44
Tones on page 146
Hot Desking on page 172
Action URL on page 176
Action URI on page 176
Resource Files on page 238
Appendix D: Configuration Parameters on page 269
Appendix G: Sample Configuration File on page 482
Major updates have occurred to the following sections:
Dial Plan on page 67
Phone Lock on page 48
Time and Date on page 50
Busy Lamp Field on page 153

Table of Contents
xi
About This Guide ...................................................................... v
Documentations...............................................................................................................................v
In This Guide ....................................................................................................................................v
Summary of Changes .................................................................................................................... vi
Changes for Release 72, Guide Version 72.25......................................................................vi
Changes for Release 72, Guide Version 72.1........................................................................vi
Changes for Release 71, Guide Version 71.165................................................................... vii
Changes for Release 71, Guide Version 71.141................................................................... vii
Changes for Release 71, Guide Version 71.140................................................................... vii
Changes for Release 71, Guide Version 71.125.................................................................. viii
Changes for Release 71, Guide Version 71.120.................................................................. viii
Changes for Release 71, Guide Version 71.110.................................................................. viii
Changes for Release 70, Guide Version 70......................................................................... viii
Changes for Release 70, Guide Version 2.0........................................................................... x
Table of Contents .................................................................... xi
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......................................................................................................10
Getting Started....................................................................... 13
Connecting the IP Phones .............................................................................................................13
Initialization Process Overview ....................................................................................................16
Verifying Startup ............................................................................................................................17
Reading Icons ................................................................................................................................18
Configuration Methods.................................................................................................................20
Phone User Interface..............................................................................................................20
Web User Interface ................................................................................................................ 20
Configuration Files..................................................................................................................20
Configuring Basic Network Parameters ......................................................................................22
DHCP .......................................................................................................................................22
Configuring Network Parameters Manually ........................................................................25

Administrator’s Guide for SIP-T2xP and SIP-T19P IP Phones
xii
PPPoE .......................................................................................................................................28
Configuring Transmission Methods of the Internet Port and PC Port .................................29
Configuring PC Port Mode .....................................................................................................31
Upgrading Firmware.....................................................................................................................34
Configuring Basic Features .................................................... 37
Power Indicator LED ...................................................................................................................... 38
Contrast ..........................................................................................................................................40
Backlight......................................................................................................................................... 42
Web Server Type............................................................................................................................44
User Password ...............................................................................................................................45
Administrator Password ................................................................................................................46
Phone Lock .....................................................................................................................................48
Time and Date ...............................................................................................................................50
Language .......................................................................................................................................56
Loading Language Packs ......................................................................................................57
Specifying the Language to Use...........................................................................................58
Logo Customization .......................................................................................................................59
Softkey Layout................................................................................................................................62
Key as Send ...................................................................................................................................65
Dial Plan..........................................................................................................................................67
Replace Rule ...........................................................................................................................68
Dial-now ..................................................................................................................................69
Area Code...............................................................................................................................72
Block Out.................................................................................................................................73
Hotline ............................................................................................................................................74
Directory .........................................................................................................................................75
Search Source in Dialing...............................................................................................................77
Call Log...........................................................................................................................................78
Missed Call Log .............................................................................................................................80
Local Directory ...............................................................................................................................81
Live Dialpad...................................................................................................................................84
Call Waiting....................................................................................................................................84
Auto Redial..................................................................................................................................... 86
Auto Answer...................................................................................................................................88
Call Completion.............................................................................................................................90
Anonymous Call............................................................................................................................. 91
Anonymous Call Rejection ............................................................................................................93
Do Not Disturb................................................................................................................................95
Busy Tone Delay.............................................................................................................................99
Return Code When Refuse ..........................................................................................................100
Early Media..................................................................................................................................101
180 Ring Workaround ..................................................................................................................101
Use Outbound Proxy in Dialog...................................................................................................103

Table of Contents
xiii
SIP Session Timer ......................................................................................................................... 104
Session Timer ...............................................................................................................................105
Call Hold.......................................................................................................................................107
Call Forward ................................................................................................................................110
Call Transfer .................................................................................................................................116
Network Conference ...................................................................................................................117
Transfer on Conference Hang Up ..............................................................................................118
Directed Call Pickup.................................................................................................................... 119
Group Call Pickup........................................................................................................................122
Dialog Info Call Pickup................................................................................................................125
Call Return ....................................................................................................................................127
Call Park .......................................................................................................................................128
Calling Line Identification Presentation..................................................................................... 129
Connected Line Identification Presentation ..............................................................................131
DTMF............................................................................................................................................. 132
Suppress DTMF Display .............................................................................................................. 135
Transfer via DTMF ........................................................................................................................136
Intercom........................................................................................................................................137
Outgoing Intercom Calls...................................................................................................... 137
Incoming Intercom Calls ...................................................................................................... 138
Configuring Advanced Features...........................................141
Distinctive Ring Tones ..................................................................................................................141
Tones .............................................................................................................................................146
Remote Phone Book ....................................................................................................................148
LDAP.............................................................................................................................................. 150
Busy Lamp Field........................................................................................................................... 153
Automatic Call Distribution .........................................................................................................159
Message Waiting Indicator ........................................................................................................162
Multicast Paging ..........................................................................................................................164
Sending RTP Stream.............................................................................................................164
Receiving RTP Stream ..........................................................................................................166
Call Recording .............................................................................................................................168
Hot Desking.................................................................................................................................. 172
Action URL ....................................................................................................................................173
Action URI.....................................................................................................................................176
Server Redundancy.....................................................................................................................179
SIP Server Domain Name Resolution..................................................................................183
LLDP...............................................................................................................................................186
VLAN .............................................................................................................................................189
VPN................................................................................................................................................192
Quality of Service ........................................................................................................................195
Network Address Translation .....................................................................................................197
802.1X Authentication .................................................................................................................199

Administrator’s Guide for SIP-T2xP and SIP-T19P IP Phones
xiv
TR-069 Device Management ......................................................................................................204
IPv6 Support ................................................................................................................................. 206
Configuring Audio Features ..................................................211
Headset Prior ...............................................................................................................................211
Dual Headset...............................................................................................................................212
Audio Codecs ..............................................................................................................................213
Acoustic Clarity Technology........................................................................................................217
Acoustic Echo Cancellation ................................................................................................. 217
Voice Activity Detection .......................................................................................................218
Comfort Noise Generation ..................................................................................................219
Jitter Buffer ............................................................................................................................220
Configuring Security Features...............................................223
Transport Layer Security.............................................................................................................. 223
Secure Real-Time Transport Protocol..........................................................................................229
Encrypting Configuration Files ...................................................................................................232
Resource Files........................................................................238
Replace Rule Template ...............................................................................................................238
Dial-now Template.......................................................................................................................239
Softkey Layout Template.............................................................................................................240
Directory Template ......................................................................................................................242
Super Search Template...............................................................................................................243
Local Contact File ........................................................................................................................244
Remote XML Phone Book............................................................................................................ 246
Specifying the Access URL of Resource Files ............................................................................247
Troubleshooting.....................................................................250
Troubleshooting Methods ........................................................................................................... 250
Viewing Log Files..................................................................................................................250
Capturing Packets ................................................................................................................253
Enabling Watch Dog Feature .............................................................................................. 254
Getting Information from Status Indicators........................................................................255
Analyzing Configuration File ...............................................................................................255
Troubleshooting Solutions ...........................................................................................................256
Why is the LCD screen blank? .............................................................................................256
Why doesn’t the IP phone get an IP address? ...................................................................256
Why does the IP phone display “No Service”? ................................................................. 257
How do I find the basic information of the IP phone?.......................................................257
Why doesn’t the IP phone upgrade firmware successfully?.............................................257

Table of Contents
xv
Why doesn’t the IP phone display time and date correctly? ...........................................257
Why do I get poor sound quality during a call? ................................................................257
What is the difference between a remote phone book and a local phone book? .......258
What is the difference among user name, register name and display name? .............258
How to reboot the IP phone remotely? ..............................................................................258
Why does the IP phone use DOB format logo file instead of popular BMP, JPG and so on?
................................................................................................................................................259
How to increase or decrease the volume?........................................................................ 259
What will happen if I connect both PoE cable and power adapter? Which has the higher
priority?..................................................................................................................................259
What is auto provisioning? ..................................................................................................259
What is PnP? ..........................................................................................................................259
Why doesn’t the IP phone update the configuration? ......................................................260
What do “on code” and “off code” mean? .......................................................................260
How to solve the IP conflict problem? ................................................................................ 260
How to reset the IP phone to factory configurations?.......................................................260
How to restore the administrator password? ....................................................................261
What are the main differences among SIP-T28P, IP-T26P, SIP-T22P, SIP-T21P, SIP-T20P and
SIP-T19P IP phones?...............................................................................................................261
Appendix ...............................................................................264
Appendix A: Glossary.................................................................................................................264
Appendix B: Time Zones............................................................................................................. 266
Appendix C: Trusted Certificates ...............................................................................................268
Appendix D: Configuration Parameters ....................................................................................269
Setting Parameters in Configuration Files.......................................................................... 270
Basic and Advanced Parameters.......................................................................................270
Audio Feature Parameters...................................................................................................390
Security Feature Parameters ...............................................................................................398
Resource Files .......................................................................................................................404
Troubleshooting ....................................................................................................................409
Configuring DSS Key ............................................................................................................410
Appendix E: SIP (Session Initiation Protocol) ............................................................................434
RFC and Internet Draft Support ..........................................................................................434
SIP Request............................................................................................................................437
SIP Header ............................................................................................................................437
SIP Responses .......................................................................................................................439
SIP Session Description Protocol (SDP) Usage .................................................................. 441
Appendix F: SIP Call Flows .........................................................................................................442
Successful Call Setup and Disconnect ...............................................................................442
Unsuccessful Call Setup—Called User is Busy ..................................................................445
Unsuccessful Call Setup—Called User Does Not Answer ................................................447
Successful Call Setup and Call Hold.................................................................................. 450
Successful Call Setup and Call Waiting .............................................................................453

Administrator’s Guide for SIP-T2xP and SIP-T19P IP Phones
xvi
Call Transfer without Consultation ......................................................................................458
Call Transfer with Consultation............................................................................................462
Always Call Forward............................................................................................................467
Busy Call Forward ................................................................................................................471
No Answer Call Forward .....................................................................................................474
Call Conference.................................................................................................................... 477
Appendix G: Sample Configuration File ...................................................................................482
Index ......................................................................................488

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-T2xP and SIP-T19P 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-T28P
SIP-T26P
SIP-T22P
SIP-T21P
SIP-T20P
SIP-T19P
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 10.

Administrator’s Guide for SIP-T2xP and SIP-T19P 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.
Routers are configured for VoIP.
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-T28P
Physical Features:
-TI TITAN chipset and TI voice engine
-320x160 graphic LCD with 4-level grayscales
-6 VoIP accounts, BroadSoft/Avaya/Asterisk validated
-HD Voice: HD Codec, HD Handset, HD Speaker
-48 keys including 16 DSS keys
-1xRJ9 (4P4C) handset port
-1xRJ9 (4P4C) headset port
-2xRJ45 10/100Mbps Ethernet ports
-1XRJ12 (6P6C) expansion module port
-19 LEDs: 1xpower, 6xline, 1xmessage, 1xheadset, 10xmemory