[HECnet] Why does FAL generate this many reply packets?

[Paul_Koning at Dell.com]

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