Krupa wrote:
We have checked up the performance of the link with the help of our serial
communication programs. We have developed programs for serial communication
using DNP protocol. We have not implemented error correction, only error
detection is done.
We have found that the link is in perfect condition and data transmitted
from one end is received without errors at the receiving end. We could not
figure out why ping reports 60% packet loss on the same link.
That is the root of the problem, with 60% packet lost, just forget it
Phindows will NOT work. That has nothing to do with Phindows, it’s
TCP/IP. I doubt it’s a configuration issue with TCP/IP. My guess is
the way you are testing the link, are you testing it both way
simultaneously. Maybe the type of system you use doesn’t like having
communication direction change constantly (has it happends with ping)
You might want to get rid of TCP/IP and use the serial link like it
would be a serial cable and use phindows serial connection capability.
That will allow you to figure out if the issue is with TCP/IP or with
link itself.
Phindows does
not allows us to access Photon on QNX machine. Does anyone have an
experience of using Phindows on similar communication links?
I have use Phindows on wireless (network) communication without
any kind of problem.
Thanks,
Krupa
Mario Charest postmaster@127.0.0.1 wrote in message
news:avmm9f$do0$> 1@nntp.qnx.com> …
Krupa wrote:
Hi,
We wish to connect a QNX computer (installed with TCP/IP for QNX) to
Windows computer with the help of direct serial connection feature of
windows.
We have tried this experiment with a serial cable connected between two
machines.
QNX computer
Socket -p1 node1 &
#ifconfig en1 node1 up
tinit -c “pppd” -t /dev/ser1 &
#ph
On a shell, #inetd &
Micorsoft Windows compuer
Direct serial connection
Once the connectivity is established with QNX machine, we run Phindows
on
TCP/IP
Connectivity functions without showing any problem. We could ping from
one
machine to other machine. On running phindows, we could login using
photon
based login dialog box.
We then repeated the same experiment on a microwave link instead of a
direct
cable connected between the two computers. We could establish a ppp link
between two machines. ping at times shows time out, and shows 60% packet
loss. With such a performance of the link, if we initiate Phindows, it
does
not allow us to logon to QNX machine.
Is there any way of enabling/implementing error correction for the data
packets transferred on a serial ppp link?
ppp already includes correction, but with a 60% packet lost with ping,
which only send a packet every seconds, so i’d expect a greater packet
lost on streaming data, I doubt there is much you can do with this.
Phindows uses TCP so even the stack will try it’s best to handle error,
but it seems the me packet lost is too great. Have you try with ftp?
- Mario
Does the TCP/IP stack correct
transmission errors? Are such problems of of Phindows not allowing a
logon,
expected on a link that is introducing errors?
Thanks,
Krupa
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