by net-point ag
11. March 2010 11:16
When using 3CX Phone System on Dual Core or Multiprocessor machines on virtualized operating system like vmware and Hyper-V, you may experience Stuttering voice quality if you have not configured your virtual environment correctly. This article explains how pm timers ( /usepmtimer switch in boot.ini ) on the machine may affect hyper v or vmware instances in which the guest os is Windows XP or server 2003.
Scenario – 3CX PhoneSystem Hyper V installation with XP or 2003 guest operating system
Problem – In these operating systems, you may encounter a situation where the IVR music files being played have jittery or bad audio.
To resolve this problem:
Limit your configuration to 1 virtual processor
Limit the configuration to use 1 virtual processor in Hyper V Settings, Processor, and set the number of logical processors to 1.
If you require 2 virtual processors
You will have to modify the Boot.ini file to use the /usepmtimer switch. To do this:
- Log on to the computer with an account that has administrative credentials.
- Click Start, click Run, type notepad c:\boot.ini, and then click OK.
- In the Boot.ini file, navigate to the line that starts with “default” in the “[boot loader]” section.
This line specifies the location of the default operating system, for example:
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS
- In the “[operating systems]” section, locate the line for the operating system that corresponds to the “default” line.
For example, if the computer is running Microsoft Windows Server 2003, Enterprise x64 Edition, the line should resemble the following:
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS=”Windows Server 2003 Enterprise x64 Edition” /fastdetect /NoExecute=OptIn
- At the end of the line, add a space, and then type /usepmtimer.
The line should now resemble the following:
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS=”Windows Server 2003 Enterprise x64 Edition” /fastdetect /NoExecute=OptIn /usepmtimer
- Save the file, and restart the computer.
The following is a sample Boot.ini file for a system that contains the /usepmtimer switch:
[boot loader]
timeout=0
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Windows Server 2003 Enterprise x64 Edition" /fastdetect /NoExecute=OptIn /usepmtimer
Fore more information on /usepmtimer switch see: http://www.news.net-point.ch/post/2010/03/18/3cx-background-information-on-usepmtimer-on-Dual-Core-or-multiprocessor-systems.aspx