Introduction to Packet Delay Variation in VOIP:
Packet delay variation indicates the overall difference in the packet arrival rate. In general the packet delay variation should be low enough for a better quality of service for the voice applications and the actual comparison graph is as shown below.
From the above graph it is clear that, the overall packet delay variation is less when the routing protocol is AODV. The average packet delay variation is more with the case of DSR routing protocol and this is due to the issue that DSR imposes more routing overhead across the peer nodes.
Even when the routing protocol is TORA the packet delay variation is more. Thus from the overall analysis it is clear that, when the routing protocol is AODV the overall packet delay variation is reduced and thus the quality of the voice application is enhanced.