[Info-vax] Slow FTP transfer Linux -> VMS

[JF Mezei]

In my limited experience, the only performance parameters I have seen are:

for FTP specifically, the WINSIZ logical mentioned before.

For the kernel, you can

$ type sys$startup:tcpip$systartup.com

$  SYSCONFIG = "$SYS$SYSTEM:TCPIP$SYSCONFIG.EXE"
$  IFCONFIG = "$SYS$SYSTEM:TCPIP$IFCONFIG.EXE"
$!
$SYSCONFIG -r inet tcp_recvspace=255552
$SYSCONFIG -r inet tcp_sendspace=255552
$SYSCONFIG -r inet udp_recvspace=65536
$SYSCONFIG -r inet udp_sendspace=65536


The send and recvspace paramegres define the "window size" (actually the
maximum window size. In modern implementations (not sure if VMS follows
this), a sending host will slowly increase the sending widnow size until
 a lost packet is detected at which point window size is recuided by
half and then starts to grow again util packet loss is again
encountered, window size has reached maximum or throughput has reached
maximum (no pauses between packlets to wait for an ack).