Yealink SIP-T48G Administrator's Manual page 13

Viewing Log Files .................................................................................................................. 523
Capturing Packets ................................................................................................................ 533
Enabling Watch Dog Feature .............................................................................................. 534
Getting Information from Status Indicators ........................................................................ 535
Analyzing Configuration File ............................................................................................... 535
Troubleshooting Solutions ........................................................................................................... 538
Why is the LCD screen blank? ............................................................................................. 538
Why doesn't the IP phone get an IP address? ................................................................... 538
Why does the IP phone display "No Service"? ................................................................. 539
How do I find the basic information of the IP phone? ....................................................... 539
Why doesn't the IP phone upgrade firmware successfully? ............................................. 539
Why doesn't the IP phone display time and date correctly? ........................................... 539
Why do I get poor sound quality during a call? ................................................................ 540
What is the difference between a remote phone book and a local phone book? ....... 540
What is the difference among user name, register name and display name? ............. 540
How to reboot the IP phone remotely? .............................................................................. 540
Why does the IP phone use DOB format logo file instead of popular BMP , JPG and so on?
................................................................................................................................................ 541
How to increase or decrease the volume? ........................................................................ 541
What will happen if I connect both PoE cable and power adapter? Which has the higher
priority? .................................................................................................................................. 541
What is auto provisioning? .................................................................................................. 541
What is PnP? .......................................................................................................................... 541
Why doesn't the IP phone update the configuration? ...................................................... 542
What do "on code" and "off code" mean? ....................................................................... 542
How to solve the IP conflict problem? ................................................................................ 542
How to reset the IP phone to factory configurations? ....................................................... 542
How to restore the administrator password? .................................................................... 543
Appendix ...............................................................................545
Appendix A: Glossary ................................................................................................................. 545
Appendix B: Time Zones ............................................................................................................. 547
Appendix C: Trusted Certificates ............................................................................................... 548
Appendix D: Configuring DSS Key ............................................................................................. 549
Appendix E: SIP (Session Initiation Protocol) ............................................................................ 560
RFC and Internet Draft Support .......................................................................................... 561
SIP Request ............................................................................................................................ 564
SIP Header ............................................................................................................................ 564
SIP Responses ....................................................................................................................... 566
SIP Session Description Protocol (SDP) Usage .................................................................. 568
Appendix F: SIP Call Flows ......................................................................................................... 569
Successful Call Setup and Disconnect ............................................................................... 569
Unsuccessful Call Setup-Called User is Busy .................................................................. 572
Unsuccessful Call Setup-Called User Does Not Answer ................................................ 574
Table of Contents
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