This thesis has compared the Mobile IPv4 and Mobile IPv6 to find out which of them performs better when it comes to send datagram from the correspondent node to the mobile node. The tests that were made to measure performance were latency, TCP/UDP throughput, loss and delay, as well as time measurement for connectivity loss for the mobile node while roaming. The tests were done using Cisco equipments and Microsoft Windows 7 Professional OS. Due to the hardware and software used, the route of datagram was the same in both scenarios since Cisco routers and Microsoft Windows 7 OS does not support route optimization for Mobile IPv6. The results showed that Mobile IPv4 performed better in all the tests done.