I am running Application A on Machine A and Application B on Machine B. Both machines are running Windows7. Application A sends RTP packets over UDP to Application B through a private LAN. We are experiencing UDP packet loss between the 2 machines and we are trying to determine if the packet loss is occurring at the network level or on the network stack of the machine.
We are running Wireshark on both machines with WinPcap. By analyzing the RTP stream in Wireshark, we can see that all the RTP packets are sent from Machine A but some packets are not received on Machine B. I understand that the UDP packets can be dropped by the network stack of the OS if for example an application don't read fast enough from its socket and the socket's buffer gets filled. But what I would like to know is this:
If I see that an RTP packet is missing with Wireshark on machine B, does it necessarily mean that the packet was not received from the network? Or is it possible that the packet was dropped at some point in the OS before Wireshark "intercepts" the packet?