On Dec 18, 2013, at 5:17 PM, Johnny Billquist <bqt at softjar.se> wrote: On 2013-12-18 23:05, Sampsa Laine wrote: I'm copying some files over from CHIMPY to RFSAXP and did a MONITOR DECNET in another window and got these rather strage results: CUR AVE MIN MAX Arriving Local Packet Rate 404.98 412.40 398.89 424.22 Departng Local Packet Rate 149.99 170.02 148.96 195.28 So I'm guessing FAL sends a BIG packet of data when transmitting a file, and the other side replies with multiple ACKs or something? Is the local machine the one sending the file? It might be something with flow control, where the receiver acks, and then later sends an update that more data can be accepted maybe? I don't know/recall enough of DECnet communications off the top of my head to properly commenet. :-) I believe VMS uses segment flow control. So at least every couple of segments it will have to send a flow control message, which is separate from the data messages. And flow control messages (unlike the analogous thing in TCP) are acknowledged. paul