We are sending an MPEG2-TS/H264 video stream over the network. This video stream is received correctly over the LAN, instead on the other end of a private WAN video quality is poor, thus suggesting packet loss over the network.
However video received on the other end of the WAN has the upper area of the image with good quality, and the lower area with poor quality (e.g. missing blocks) i.e. the first N lines of the image are always good quality (with N randomly changing).
Does this suggest the possible causes for the issue? E.g. if we were experiencing random packet loss, I expected random missing blocks across the whole image, why the first N lines are always good quality instead?