PMTU Auto Discovery
Theoretically, this is supposed to optimize throughput by ensuring that there is no packet fragmentation along the entire path to the remote host. However, this only works properly if all the servers along the path are running Microsoft MSFT server software that supports this function. This is very often not the case of course; one only needs to consider the very large number of Unix/Linux servers now used on the Internet! When Auto Discovery is not activated the system will automatically use the MaxMTU value set by Internet Tuner.