The paper discusses algorithms to solve packing optimization problem, which arises in sorting and packing of small-lot cargo in containers in mainline transportation networks or in merging messages into virtual containers in backbone data transmission networks. A problem statement is proposed and its specific properties and approaches to the solution are discussed. The convergence and time complexity of the number of heuristic algorithms are analyzed and numerical experiments are used to investigate their comparative efficiency. It is shown experimentally that solutions results obtained by different optimization strategies based on networks that have up to 500 nodes differ by no more than 2.65%.