As industry of information technologies evolves, demand for high speed data transmission steadily increases. The need in it can be found in variety of different industries – from entertainment with trends for increasing of video to scientific research. One of the consequences is a demand for new improved transport protocols that would use the capacity of Long Fat Pipes by maximum, where common TCP performs much slower than it is expected. Such protocols are mostly based on UDP and work at the user space. To improve their network throughput, there is an option to implement sending data in a multi-threading way, but that can bring complications with it. One of the main obstacles is a possibility of out-of-order delivery due to race conditions. This problem is researched in current paper. Causes of reorder are studied regarding UDP-based transport protocols. Based on the results of the testing, a simple algorithm for compensating out-of-order delivery is proposed. It’s effect then is analysed on the example of RMDT.