Martin Bürkle írta: > Hi NG, > > I have writen a programm using TCP sockets. After i get the connection > to another socket I cut the Ethernet cable. Then I send a message. > The program doesnt raise any exception. Can somebody tell me why and > give me a hint how to get an exception > Okay, let's suppose you do not cut the ethernet cable and your message arrives on the other side, but the receiver program has a problem (not enough memory, bug in the handling code etc.) so your message is not processed on the other side. Most of the time, you do not only want to check if your message was transferred - you also need to check if that is actually processed. The TCP protocol cannot do this for you.Your clients needs to send back another message that notifies the sender about successful processing. Your sender program can wait for this notification, and then raise an exception after some timeout.
In other words, you need to develop your own communication protocol over TCP/IP. You should try to minimize the number of send-receive-notification cycles, because the answer time can be high, compared to the transfer speed of the communication channel. And also because notifications are usually small, and they a buffered for a while... I have seen a paper about designing protocols over TCP/IP, but I do not remember now. Others will help you for sure. Please also consider UDP (if possible), which can be much more efficient. Best, Laszlo -- http://mail.python.org/mailman/listinfo/python-list
