Server-push-to-client application that uses port 80 only - .NET?

Posted on 2004-11-10
Last Modified: 2008-01-09

I'm looking for a way to write a .NET client/server application that uses port 80 to push communication from the server to the client.  An example would be a chat application with these characteristics:
 - runs on the client all the time.
 - the server decides when to send new information to a client
 - upon receiving this push from the server, the client reacts by popping up on the screen.

Some notes:
My guess is that I need to maintain an open session over port 80 - but I don't think it needs to be http.  The "client" can not run as a server, however - in other words, I can't install a web-server-lite on the client and expect it to respond to incoming http requests: corporate firewalls would prevent that.  Also, a client-pull will not work because clients have to react to new information on the server within 4 seconds, and that's too many requests for both the client and the server - both would get bogged down.  I've seen an application that seems to run completely on port 80 without client pull's called BoldChat ( and I would think that the way this program works would apply here as well.  

Any suggestions on how I would go about doing this with a .NET (or Java, or other) client?
Question by:jeffv2718
    LVL 27

    Accepted Solution


    Here is where I found good examples for getting started in VB.Net
    Look at the sample app. called VB.NET How-To Sockets Client
    Just change the port num to 80


    Link for ASP programs...
    LVL 18

    Expert Comment

    One other way, not that good one, but works. if you want to use webservices.
    I once made a Webservice and called a Webmethod's say BeginXXX method. Now that is an asyncronous method, The control is returned to the client. The webservice holds the control on its side.. when ever some thing is to be returned to the client, server returns from that method XXX, and the controls EndXXX method is called. Which at the end initiates the BeginXXX again. So it keeps on moving in an Infinite loop

    Hope it makes a little sence..
    I am writing an article on it. If I somehow complete it. I will place it somewhere for everyone :)

    Featured Post

    What Is Threat Intelligence?

    Threat intelligence is often discussed, but rarely understood. Starting with a precise definition, along with clear business goals, is essential.

    Join & Write a Comment

    For those of you who don't follow the news, or just happen to live under rocks, Microsoft Research released a beta SDK ( for the Xbox 360 Kinect. If you don't know what a Kinect is (http:…
    Real-time is more about the business, not the technology. In day-to-day life, to make real-time decisions like buying or investing, business needs the latest information(e.g. Gold Rate/Stock Rate). Unlike traditional days, you need not wait for a fe…
    In this seventh video of the Xpdf series, we discuss and demonstrate the PDFfonts utility, which lists all the fonts used in a PDF file. It does this via a command line interface, making it suitable for use in programs, scripts, batch files — any pl…
    Access reports are powerful and flexible. Learn how to create a query and then a grouped report using the wizard. Modify the report design after the wizard is done to make it look better. There will be another video to explain how to put the final p…

    746 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    15 Experts available now in Live!

    Get 1:1 Help Now