>The main issue I can think of is the possibility of losing the connection in transit. Does the device have any sort of rollback function? How does the device handle incomplete packets?

Loosing connection in transit is the main reason I went with the connect,send,receive, disconnect approach in the first place. The device does not have a rollback function (I don't think it is needed, correct me if I am wrong). If the device receives an incomplete (or invaild formated) package (command) the device will not respond with anything and the PC app will eventually timeout. The same way if the PC app doesn't receive a correctly formated package it will reject the packet (and try again)


>Also, how does the device handle packets received in the wrong order?

The device will only handle one connection at a time (so it can only process one packet (command) at a time. PC app sends one command and expects to receive one packet.

>Is it connected to a router or a switch?
The device will most likely be connected to a router or a switch. Will that make a difference? Why did you ask that question? (the device will be sold to hundreds of locations ranging in size)

>How long will the transmission take?
when testing localy (PC to switch to device) the round trip time (connect, send,receive,disconnect) is about 300ms. When connecting over the internet the transmission time is about 700ms

>How important is performace compared to reliability?

Well that is the million dollar question. I want it fast and reliable :) I have been working on reliability lately and on a local network (LAN) I see failure rates down to 0.0016% and transmission rates around 300ms. Now when I connect over the internet it is a different story I get failure rates around 90% mostly because the connect step fails (it fails several times then it works a couple of times then it starts failing again).

>
>All of these questions will determine which way you should go. Developing the software will definitely be less complicated if each packet is a separate connection.

I still think I like the one packet per connection idea, but I did second guess myself a little here today and that was the reason for this post.

I appreciate your thoughts and hope you will have time to post some more comments.

Thanks,
Einar