Cisco Unity Connection

PIMG Clips Audio at the End of Recorded Messages

Document ID: 116399

Updated: Aug 07, 2013

Contributed by Scott Hills and Brad Gruesbeck, Cisco TAC Engineers.



This document describes a problem encountered when Cisco Unity Connection is integrated with PBX via PBX IP Media Gateway (PIMG) and provides a solution to the problem.


When you play a recorded message, the last one to three seconds of the message are clipped.


Complete these steps in order to troubleshoot the problem:

  1. Take a network capture from PIMG while the issue is reproduced.
  2. Take a sniffer capture from Unity Connection while the issue is reproduced.

In the captures, you might notice that the full Real-Time Transport Protocol (RTP) stream is heard if you use the Routing Information Protocol (RIP) in order to pull out the RTP stream and listen to it.


A common cause of this issue is that Voice Activity Detection (VAD) is enabled on the PIMG.

In order to correct this problem, navigate to Configuration > VoIP > Media > Audio > Voice Activity Detection and select the VAD value No.

Updated: Aug 07, 2013
Document ID: 116399