Yealink SIP-T2XP

Table of Contents
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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