Windows XP(SP2) PPTP Windows VPN Client and IP Office
Phone Manager Pro
An issue has been noted when using VPN clients on Windows XP SP2 PCs. When
directly connecting to a network without using VPN, both XP SP2 and XP SP1 work as
expected.
However, when connecting to the network via VPN using a PPTP Windows client on
Windows XP SP2 and 3.0(13) Phone Manager Pro, there is an issue with the quality of
the audio path in one direction. The Phone Manager user connected via VPN to the
customer’s network hears excellent voice quality. The other user hears an intermittently
distorted audio path.
This problem does not occur when using Windows XP SP1.
In order to resolve this issue, the quality of service (QoS) packet scheduler on the XP SP
2 PC must be uninstalled. Simply disabling the QoS packet scheduler does not resolve
this issue.