Yealink SIP-T48G Administrator's Manual page 196

Microsoft Lync Edition Administrator's Guide for SIP-T2_Series and T4_Series IP Phones
Brazil

Belgium

Chile

China

Czech

Czech ETSI

Denmark

Finland

France

Germany

Great Britain

Greece

Hungary

Lithuania

India

Italy

Japan

Mexico

New Zealand

Netherlands

Norway

Portugal

Spain

Switzerland

Sweden

Russia

United States

Configured tones can be heard on IP phones for the following conditions.
Condition
Dial
Ring Back
Busy
Congestion
Call Waiting
Dial Recall
184
Description
When in the pre-dialing interface
Ring-back tone
When the callee is busy
When the network is congested
Call waiting tone
When receiving a call back