If you have the 403 running on 3.05xx then it will not work.
You need to run the "normal" 3.0 but then the DT phones stop working.
See this:
IMPORTANT INFORMATION
The Avaya 20xx (DT) handsets are not supported in IP Office 3.0. A further IP
Office build will be released in the near future, IP Office 3.0DT, which will support
20xx handsets. However this will not support the features or applications
described in this document. Please refer to the separate communication that was
sent out regarding this.
Note: The IP403DT can run 3.0 software but there is no support for the
connection of DT handsets to the 8 onboard ports.
Please also note that IP Office 3.0 software is not supported on the IP401
platform.
Homo sapiens non urinat in ventum
honey, i fried the IP Office !!!
Sarcasm, it's only one of the services I offer.