| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1603.1 | Theory and practice | SDSVAX::SWEENEY | I was focused when focus wasnt cool | Thu Oct 19 1989 11:23 | 21 |
| "Timing" isn't everything, but assuming that the WAN is layered on
reliable protocols as DECnet, OSI, and X25 are, it is the principal
consideration.
In theory, X is independent of any timing considerations.
In practice, the Digital implementation of X over specific transports
like DECnet and TCP/IP has timing considerations.
In theory, client applications shouldn't care about timing, but the
human users of very slow networks using applications that perform a lot
of drawing will appear slow or unusable at less than T-1 (1.5 Mbps) in
my experience.
And forget about images and smooth mouse tracking. Now, there's always
someone who'll say that clock will run over 2400 baud. That confirms
the theory.
Whether your customers' real applications will run on a WAN requires
some thought about the traffic created by the application.
|
| 1603.2 | Has anyone had success over a WAN? | SPCTRM::GORCZYCA | | Fri Oct 20 1989 17:45 | 24 |
| Well, this may be as good a spot to ask as any...
Does ANYONE have much experience running DECwindows outside of a LAN?
Recently, I tried to connect to an application over leased lines (I think)
running DECnet between Littleton and Marlboro. The application that I tried
to start was VUE$MASTER. Everytime I tried, after several minutes, I'd get
the following error message:
XIO: non-translatable vms error code: 0x2DBA002, vms message:
%decw-e-cnxabort, connection aborted
%XLIB-F-IOERROR, xlib io error
Due to the delay, I assumed that it was due to some time-out somewhere, but
have no idea of where to start looking. Keep in mind that I'm your classic
"naive user". I just "followed the instructions" and expected it to work.
Anyone care to hazard a guess as to what I might tweak?
Thsnks,
John
|
| 1603.3 | How good is path? | DELNI::MHARRIS | Netwrk Integ'n Projects | Fri Oct 20 1989 18:29 | 24 |
| I routinely run X appliocations from Littleton,MA to Merrimack.
Works fine, even with really slow lines. I don't think the timeouts are
killing you DIRECTLY, but something else making the network
running really slow, or flaky, or...
Have you tried DTSEND to 'bounce' packets between the two nodes to see
how well the path is?
NODE1:
$ MC DTSEND
> CONN/NODE=NODE2
> DATA/SIZ=512/SEC=30
(A full report indicating the effective baud rate will be printed
after 30 seconds...)
> DISC/NODE=NODE2
$
Try it, see what happens
|
| 1603.4 | | NAC::THOMAS | The Code Warrior | Fri Oct 20 1989 22:55 | 4 |
| I've do X over DECnet between ZKO and LKG all the time. I've also
done it between LKG and MRO,MLO,SHR,WFO,CXO,WRO, and SNO. SNO was
slow but the others were quite nice. I normally use remote DECterms.
|
| 1603.5 | Who can beat 3500 miles? | KASINO::TALLETT | Just one more bug to fix... | Mon Oct 23 1989 12:57 | 14 |
| DECwindows works fine over a WAN....
I ran a DECimage display from here in Karlsruhe, West Germany to
WSL in Palo Alto, California. I make that 5500 kms (3500 miles)
and network speed was waaayyyyy down (took about 15 minutes to
get a response to a mouse click!).
Now, do we have someone from Australia?...... :-)
Regards,
Paul Tallett,
CEC Karlsruhe,
West Germany
|
| 1603.6 | Some applications are better than others | MARVIN::COBB | Graham R. Cobb (Wide Area Comms.), REO2-G/H9, 830-3917 | Thu Oct 26 1989 19:59 | 13 |
| I have tried this a little (not at all scientifically!) and found that some
applications are much more sensitive than others. Bookreader is the worst
one I have found. DECterm is the most robust I have found.
The answer is to try it out for your particular applications.
Make sure, of course, that you do everything you can to reduce transit delay
across the WAN. See the MARVIN::X25PSI conference for a discussion of
things you can do to help that (although it depends on your PTT). The
crucial thing is to use a large packet and window size for the DLM SVC.
Graham
|