[Info-vax] Nagle problem in remote DECterm on VAX, revisited

[H Vlems]

On 28 nov, 20:19, smithfarm <presnyprek... at gmail.com> wrote:
> This is a problem I have been having since I first got back to VMS this
> past August. At that time I asked for help here but wasn't competent to
> follow any of the advice given.
>
> Now, hopefully, I have made some progress and I'd like to give it
> another shot.
>
> The problem occurs when I create a DECterm from the VAX (running OpenVMS
> v7.3) on a remote X server. The DECterm appears and I can enter commands
> and see output - so far so good. However, there is an unreasonably long
> delay between when I type and when the characters I type are displayed.
> For example, if I type 30 or so characters rapidly, there is a 3-second
> delay before the characters appear in the DECterm window.
>
> This annoying "Nagle delay" happens regardless of the X server being
> used (so far I've tried two: Ubuntu and Windows/Xming).
>
> Now, in addition to the VAX I also have here an RX2600 running v8.4.
> When I connect from Windows/Xming to this system and run DECterm, there
> is no annoying "Nagle delay". From this I deduce that the Nagle problem
> is somewhere in the VAX TCPIP implementation. At this point, I am using
> OpenVMS TCPIP Services, not the alternative MultiNet.
>
> Theoretically, I see one possible solution and one possible workaround:
> tell disable Nagle in TCPIP Services (but how?) or run MultiNet instead
> of TCPIP Services.
>
> Thanks, as always, for any help, comments, suggestions.
>
> Nathan

I can't type, just two fingers and the occasional thumb to hit the
space bar. No wonder this delay is new to me ;-)
What happens here? The user types charachters and they get sent to the
X-client who processes them.
The X-client sends the result, the visual effect of these characters
back to the X-server.
Which gives several opportunities to slow things down I guess. Like:
how many characters are assembled in one packet sent bu the Xserver,
how much processing is required on the Xclient and how well can the
Xclient utilize the packet stream that is returned to the Xserver.
Sending characters may be inefficient: wasn't that where LAT performed
better than cterm/DECnet?
What protocol are you using between the Xsystems: DECnet or IP (or
LAT)? What happens if you change to one of the others?
How much cpu load has the Xclient during these sessions while you're
hammering away on the keyboard of the Xserver?
A somewhat less likely issue: how busy is your network during all
this, are there games being played or other network intensive things
going on?
No answers I'm afraid but *lots* of things to check....
Hans