Please Help!!! - Microsoft's UDP Application: msocudp

[roshan]

To Any Whom Can Answer,



Hello. I have used Microsoft's Visual C++ 6.0 UDP application
(msocudp) to retrieve packets from a device that is connected to our
network. Since we are using UDP, we have included code for handling
hanshaking (i.e. acknowledgement and finish packets.) After sending a
command packet, the UPD application will receive the acknowledge
packet for the command packet and then a finish packet after the
command has been issued on the device. If the UDP application hasn't
received a finish packet, it will wait until it does so before sending
subsequent command packets. The UDP application can also send a
command packet and expect to receive a data packet and finished packet
thereafter from the device. The data packet provides data to be
processed by the UDP application to determine the results of
particular tests performed on the device.



There are cases where after the UDP application sends a command packet
and receives back an acknowledgement packet, it will expect back not
just one data packet, but perhaps 10 data packets and then a finish
packet. The problem is that sometimes the UDP application will receive
all 10 data packets and a finish packet and sometimes, it will only
receive 9 data packets and not the 10th data packet and the finish
packet. I even used Ethereal (packet sniffer) to ensure that all 10
data packets and finish packets were being sent to the computer and
they most certainly were!



So I stumped on why the UDP application will not recieve all the
packets. It seems in the code, the problem is that the OnReceive()
callback function doesn't get invoked for all the packets.


Please provide any help, if you know the answer.



Regards,



Roshan

Exeltech Software Developer

 

[roshan]

* (e-mail address removed):


Yes, the bug is on line 42.

Or perhaps it's the cast on line 666.

Anyway, if this doesn't help, try to post the question in a group
where it's on topic, and possibly keep in mind that UDP packets do not
have guaranteed delivery (note that discussing that is off-topic here).

Cheers, & hth.,

- Alf

--
A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

Thank you Alf for your response. Which source file from the Microsoft
UDP application (msocudp) are you talking of?

- Roshan

 

[Kai-Uwe Bux]

Please don't quote signatures.

Thank you Alf for your response. Which source file from the Microsoft
UDP application (msocudp) are you talking of?

Apparently "hitchhiker.cpp" for the first possibility and "revelation.cpp"
for the second.


Best

Kai-Uwe Bux