Based on recent releases such as Release 10.2.x and earlier 8.x versions, the guide includes:
: You must configure the client library to point to the correct Telephony Services server (Tlink). Core Telephony Operations The guide outlines how to handle basic call control: JTAPI programmers - Avaya Documentation
Avaya provides extensive tables of TsapiError codes (e.g., ERR_PROV_NO_PERMISSION , ERR_RESOURCE_UNAVAIL ). The guide explains exactly what each means and how to recover.