I'm using FreeSWITCH on EC2 to call into a conference bridge and record the audio from the conference. It works well except for one thing: the recording contains all the audio from the call, but the duration of the file is shorter than the call. The duration is typically 3-5 seconds shorter than the call for each 5 minutes of call. On a recent test, wall clock showed a duration of 15:32.93 but the duration of the recording file was 15:19.96. The ugly part is that this only happens on EC2 instances where there is some CPU steal time (<5%) occurring.