Forwarded call Not getting disconnected

[kabr]

We have installed Avaya IP Office 500V2 version 9.1. After the installation, call from outside trunk line via auto attend (Voice Mail Pro version 9.1), is connected to reception. After forwarding that call to the user extension from the reception, forwarded call is not getting disconnected. (Even after the call is disconnected from the originator side, the user side extension keeps on ringing).
The box included PRI and Analog trunk card. Now they are using Analog Trunks lines only.
Waiting for the solution.......

[thiel2]

The analog trunks are not receiving a reliable disconnect signal from the telephone company. Ditch them and get the PRI working instead, as it provides call progress for all of the channels.