TCP Socket question

spesh · Joined: 28 Mar 2006 Posts: 10

I'm developing an application for transfering data over sockets. The client application (Windows C#) connects to a socket and then transfers a reading following a request.

It seems to work fine most of the time, but every now and again I see a message re-transmission (using Wireshark Network sniffer) and then I lose connection and can't re-connect. My PIC code is based on Ex14 supplied with the CCS TCP stack.

My question is this : Is it OK to leave the socket connected whilst the readings are made (this could be a long time, e.g. 1 hour) or is it best to connect, read/write and disconnect each time I want a reading (probably every 10 seconds or so) ?

Regards

Alan

sohailkhanonline · Joined: 06 Mar 2008 Posts: 35 Location: pakistan

hi
in timeout also consider the time after which your connection is terminated by other side. Make this your limiting factor of socket time out as you are not going to distributed system so no question of network overloading is here
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sohail khan

andrewg · Posted: Wed May 21, 2008 9:24 am

I had a problem with long term TCP connections at one time. They would stall and I'd need to disconnect and reconnect. What I found in the "tcp.c" file was a few lines with a comment "TODO: review this". Below that were two lines:

spesh · Joined: 28 Mar 2006 Posts: 10

Andrew

I can't find that line of code in my TCP stack source.

Which version of the stack are you using ?

Regards

Alan

andrewg · Posted: Thu May 22, 2008 9:29 pm

The CCS port of the Microchip v3.75 stack.
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Andrew

Dimmu · Joined: 01 Jul 2007 Posts: 37

I don't know if this can help but some of the CCS examples are bugged.

Try to print the state of all the defined sockets in your code. Maybe it is just a question of initialisation of variable.

Dimmu