Avaya one-X 1603SW - Manual (Page 6)

Overview of phone buttons and features
Name Description
Message Waiting
Indicator
An illuminated red light in the upper-right corner of your
phone indicates you have voicemail messages waiting. If
Visual Alerting is enabled, this light flashes when you
receive an incoming call.
Introduction to the 1603/1603SW/1603-I/1603SW-I IP Telephone
6 Avaya 1603/1603SW/1603-I/1603SW-I IP Deskphone User Guide February 2010