Listening-Established

Hello

I have a question regarding a function in Port Explorer. It is about the ”status” field. When a program doesn’t have connection to the net, it says ”Listening”, and when the program establish a connection it says ”Established”. That works fine on for example Skype.exe and msnmsgr.exe which uses TCP Protocol. But when I uses for example PicoPhone which is a small telephone-program which uses UDP Protocol, it all the time states ”Listening” in the status for PicoPhone.exe even I establish a conversation and PicoPhone by this is active on the net. Isn’t that an error ?

B.rgds
Peter.

 

Hi there Peter,

The TCP and UDP protocols are fairly different (although they both use the TCP/IP transport).

UDP is a "connectionless" protocol. Imagine you want to talk to a friend... if you used UDP, it would be equivilant to throwing him a piece of paper with your message on it, and _if_ he receives it (there's a chance he might not), then he'll probably throw a piece of paper back at you with a message of his own. On the other hand, if you used TCP, you'd have to first shake your friends hand and essentially greet him first (which basically authenticates each of you, albeit not in an overly secure way), and then keep holding your friends hand while you exchanged messages with them - you must remain connected to exchange messages in a TCP session.

TCP is the more reliable protocol as it essentially guarantees your messages will reach their target - if they don't, an error will be triggered. However with UDP, you can send messages but you have no way of knowing whether or not they reached their target.

So for example, you will never see a UDP socket with a status of "CONNECTING", as all they can really do is listen, send and receive, whereas TCP sockets can listen, send, receive, connect, and disconnect.

This is just a very general outline of TCP and UDP, but there's also similar descriptions in the Port Explorer helpfile which I'd encourage you to browse through, as it will not only answer many of your Port Explorer questions but also arm you other useful information

 

Hello

Thanks for your quick respond, such fast support pleases me very much. I have just started to work with Port Explorer and I am happy for your help. I have recently seen that there a couple of times have been written about the following ”Im having problems with socket spy......each time i launch it it minimizises to the task bar & i cant get it back....Ive reinstalled port explorer but still cant maximise the port explorer part.” That I have experienced 4 times and I have only been using the program for 2 days. I use the new version 1.800. I have Win XP SP1. I solve the problem as described, but it shows that the error hasn’t been corrected in version 1.800.

Regards

Peter.

 

Hi Peter, you mean this problem described here?
http://www.wilderssecurity.com/showthread.php?t=15180

I never have it minimizing automatically; i set it to minimize to systray, did you try that?