Martin James wrote:
> I've got this customer with a couple apps runnning. One app is a TCP
> client and the other a server. These apps talk to each other fine in
> the lab and at many other customer sites - there is nothing special
> about them comms-wise, it's just a plain, low-bandwidth, TCP
> connection between a couple of Delphi apps using ICS.
>
> At this particular site, the client connects to the server OK but can
> then not exchange data with it. The client and server logs shows
> the successful connection from the client.
>
> One aspect of the connection is that the client sends 'echo' requests
> to the server every five seconds, (using our protocol on top of the
> TCP). The client does not get the echo and so disconnects from the
> server and attempts to reconnect - which is again successful, only to
> disconenct again after five seconds. The result is continual
> connect/5-sec wait/disconnect.
>
> It appears as though the TCP connect handshake works fine but the
> subsequent data exchange attempt over the 'accepted' socket-pair does
> not work at all...
do you change ports at some point of the communication? do you create
any additional thread that does the communication?
>
> The network admin is adamant that all firewalls/routers have been
> configured appropriately. Am I the only one who does not believe
> this?
reading your post, no, but I do not know your code so it may be one of
those bugs that appear only in rare configurations or occasions.
>
> Can anyone suggest anything else that might be wrong?
>
Can you ask the network admin to use Ethereal or any other packet
sniffer to check what the real communication is?
--
Best regards :-)
Guillem Vicens Meier
Dep. Informatica Green Service S.A.
www.clubgreenoasis.com
