We have the following test scenario: 2 fixed nodes (a sender and a receiver) A and D and 2 mobile nodes, B and C, moving between them. B and C start from A and D respectively and move towards each other. They are in contact for a short duration in between A and D. When they are in contact, they do not have any contact with the fixed nodes. We send data from A and use the mobile nodes to carry the bundles to D. 

The configuration we were using is epidemic routing and we send a file of 12MB, fragmented proactively in 1MB payload size. 

At the sender, we get 12 bundles of 976.7K and 1 bundle of 569.3K. We assumed that the same number of bundles with identical sizes will be at the receiver. However, after all the bundles have been delivered at the receiver, we see that there are 11 bundles of 976.7K, 1 bundle of 12.1K and one bundle of 540.1K.

Is it normal for there to be a discrepancy in the bundle sizes on both sides? If so, why is there a difference? Note that we do not run the dtninbox application on the receiver side to extract the file to the application layer.

It would be great if you could also give us a short description of how epidemic routing is implemented in your code.

Regards,

Sandra