Yealink SIP-T21 E2

Administrator’s Guide for SIP-T2 Series/T19(P) E2/T4 Series/T5 Series/CP860/CP920 IP Phones
xxiv
Jitter Buffer ..................................................................................................................................................................... 884
Noise Suppression....................................................................................................................................................... 888
Smart Noise Block ....................................................................................................................................................... 889
DTMF .......................................................................................................................................................................................... 890
Methods of Transmitting DTMF Digit ................................................................................................................. 891
Suppress DTMF Display ............................................................................................................................................ 897
Transfer via DTMF ........................................................................................................................................................ 898
DTMF Send Event Flash ............................................................................................................................................. 900
Play Local DTMF Tone ............................................................................................................................................... 902
Voice Quality Monitoring (VQM) .................................................................................................................................... 903
RTCP-XR ........................................................................................................................................................................... 904
VQ-RTCPXR .................................................................................................................................................................... 905
Configuring Security Features .................................................. 923
User and Administrator Passwords................................................................................................................................ 923
Auto Logout Time ................................................................................................................................................................. 925
Phone Lock .............................................................................................................................................................................. 926
Transport Layer Security (TLS) ......................................................................................................................................... 938
Secure Real-Time Transport Protocol (SRTP) ............................................................................................................ 949
Encrypting and Decrypting Files ..................................................................................................................................... 952
Configuration Parameters ........................................................................................................................................ 952
Encrypting and Decrypting Configuration Files .............................................................................................. 956
Encrypting and Decrypting Contact Files .......................................................................................................... 959
Incoming Signaling Validation ........................................................................................................................................ 960
Troubleshooting ......................................................................... 963
Troubleshooting Methods ................................................................................................................................................ 963
Viewing Log Files ......................................................................................................................................................... 963
Capturing Packets ........................................................................................................................................................ 978
Enabling Watch Dog Feature .................................................................................................................................. 981
Getting Information from Status Indicators ..................................................................................................... 982
Analyzing Configuration Files ................................................................................................................................. 983
Exporting All the Diagnostic Files ......................................................................................................................... 986
Ping and Traceroute ................................................................................................................................................... 987
Troubleshooting Solutions ................................................................................................................................................ 989
IP Address Issues.......................................................................................................................................................... 989
Time and Date Issues ................................................................................................................................................. 990
Display Issues ................................................................................................................................................................ 990
Phone Book Issues ...................................................................................................................................................... 991
Audio Issues ................................................................................................................................................................... 991
Wi-Fi and Bluetooth Issues ...................................................................................................................................... 992
Firmware and Upgrading Issues ............................................................................................................................ 992
Provisioning Issues ...................................................................................................................................................... 994