Changes are coming to NetScanTools Pro v11 Packet Generator that will help you do QoS testing. Lots of work has gone into changing the interpacket timing algorithms so that the leading edge (beginning) of a packet is as close as possible to the timing you have entered. For instance, if you have entered a 10ms packet interval (interpacket timing), Packet Generator now puts the packets out at the desired interval with microsecond resolution.
This new algorithm will be applied to all packet types, TCP, UDP, ICMP, CDP and RAW. It is best used for sending UDP packets because if you are thinking VOIP or video that's where things like jitter and packet delay variation are important.
Other changes to Packet Generator include the removal of that floating status window - it caused timing delays due to updating the window. The new packet burst mode is now operational where if you put the packet delay at zero (0), it sends a burst of packets defined by the number of duplicated packets to send out to the target. This burst mode sends the packets as fast as the interface can send them.
Both accurate interpacket timing and burst mode can be helpful in termining the location of bottlenecks and poorly performing devices.
A couple other things are being added to Packet Generator before release - and there was one bug that was fixed which affected users that have more than one outgoing interface.