.NET is too high-level for this sort of operation. This requires very low-level APIs and implementations with the Microsoft networking protocols, which also requires extremely efficient code with a small footprint - another reason not to use .NET. There are already several commercial (typically free for home use) applications that do this already. This has been discussed in the forums before. If you want to see how that thread progressed (to the same conclusion), please click "Search comments" directly above the message board. Microsoft MVP, Visual C# My Articles

koosha qaffari wrote: how can we understand a process request a socket is there any message and if there is wich messages REALLY I AM VERY SOORY I CAN'T UNDERSTAND WHAT YOU HAVE WRITTEN,IF YOU KNOW HINDI,PLS DESCRIBE ME IN HINDI MAY BE I KNOW ANSWER TO YOUR PROBLEM ----------------------------- "I Think It will Work" ----------------------------- Alok Gupta visit me at http://www.thisisalok.tk

Really i thought that using the hook would wind up degrading performance, and that a seperate socket layer was used. Interesting thanks ;) Discovery consist of seeing what everybody has seen and thinking what nobody has thought -- Albert Szent-Györgyi Name the greatest of all the inventors: accident --Mark Twain

Something to begin with Here[^] WinPcap: the Free Packet Capture Architecture for Windows [^] Papa while (TRUE) Papa.WillLove ( Bebe ) ;

http://winpcap.polito.it/ - Go there and find the development documentation. I have used it to capture packets before using C++. However, i do not know if they yet support capturing packets from a modem. I am also unsure if it can allow you to block packets from coming in. Its the best help i can offer. :) if i want to this with combining manged and unmanaged c++ code what can i do? This will require most likely using unmanaged and managed code, however, it is not too hard? :confused: Just, implement as little as possible in unmanaged to talk with the dll for the packet driver.

How is this much different from using the NDIS Hook code availble in WinPKFilter that I mentioned? The source you site is written in C/C++ and would still require pinvoking for it to work with .NET. "You can have everything in life you want if you will just help enough other people get what they want." --Zig Ziglar The Second EuroCPian Event will be in Brussels on the 4th of September Can't manage to P/Invoke that Win32 API in .NET? Why not do interop the wiki way! My Blog