Yealink SIP-T2XP Administrator's Manual page 15

Why doesn't the IP phone display time and date correctly? ........................................... 248
Why do I get poor sound quality during a call? ................................................................ 248
What is the difference between a remote phone book and a local phone book? ....... 249
What is the difference among user name, register name and display name? ............. 249
How to reboot the IP phone remotely? .............................................................................. 249
Why does the IP phone use DOB format logo file instead of popular BMP , JPG and so on?
................................................................................................................................................ 250
How to increase or decrease the volume? ........................................................................ 250
What will happen if I connect both PoE cable and power adapter? Which has the higher
priority? .................................................................................................................................. 250
What is auto provisioning? .................................................................................................. 250
What is PnP? .......................................................................................................................... 250
Why doesn't the IP phone update the configuration? ...................................................... 251
What do "on code" and "off code" mean? ....................................................................... 251
How to solve the IP conflict problem? ................................................................................ 251
How to reset the IP phone to factory configurations? ....................................................... 251
How to restore the administrator password? .................................................................... 252
What are the main differences among SIP-T28P , IP-T26P , SIP-T22P , SIP-T21P , SIP-T20P and
SIP-T19P IP phones? ............................................................................................................... 252
Appendix ...............................................................................255
Appendix A: Glossary ................................................................................................................. 255
Appendix B: Time Zones ............................................................................................................. 257
Appendix C: Configuration Parameters .................................................................................... 260
Setting Parameters in Configuration Files .......................................................................... 260
Basic and Advanced Parameters ....................................................................................... 260
Audio Feature Parameters ................................................................................................... 376
Security Feature Parameters ............................................................................................... 384
Upgrading Firmware ........................................................................................................... 389
Resource Files ....................................................................................................................... 392
Troubleshooting .................................................................................................................... 397
Configuring DSS Key ............................................................................................................ 399
Appendix D: SIP (Session Initiation Protocol) ............................................................................ 422
RFC and Internet Draft Support .......................................................................................... 422
SIP Request ............................................................................................................................ 425
SIP Header ............................................................................................................................ 426
SIP Responses ....................................................................................................................... 427
SIP Session Description Protocol (SDP) Usage .................................................................. 430
Appendix E: SIP Call Flows ......................................................................................................... 430
Successful Call Setup and Disconnect ............................................................................... 431
Unsuccessful Call Setup—Called User is Busy .................................................................. 433
Unsuccessful Call Setup—Called User Does Not Answer ................................................ 435
Successful Call Setup and Call Hold .................................................................................. 438
Successful Call Setup and Call Waiting ............................................................................. 441
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