Accessing a client id from within a web service

Hi

I am using Visual Studio 2005 with VB 2005 and investigating Web Services.

I have a VB client application that accesses a Web Service. This works fine, but I would like to know if there is a way to obtain some kind of unique id/reference of the VB client application from within the Web Service.

I would like to save this id/reference somewhere (possibly in a file or database) and then, when the Web Service responds back to the client and the connection between the client and Web Service is then closed, I would like some other application to be able to access the saved id/reference and send a message to the client.

Does anyone know how to accomplish this or head me in the right direction

Thanks

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Accessing a client id from within a web service

DotNet_Student
I understand most of what you are doing.

There isn't any way around the firewall. You would need to have the firewall opened for this special purpose. You could always have a webservice running on the client that the server called when it needed to send a message. This would require that port 80/443 was open and forwarded to the client IF it is behind a firewall.

Maybe you should think more along the lines of pulling data instead of pushing it. Have the client check for new messages every few seconds or minutes. This way you don't need any special firewall handling. The client starts by sending the initial message. It then checks for new messages addressed to it every say 15 seconds. This should give you everything you are talking about above. The initial web service could be on one machines and the other message retrieval service could be on the same or a different server.
Dipti Bangalore
Thanks for your reply Rick.

Here's what I was thinking:-

1) An application runs on a client server

2) The client app calls a web service to do some processing

3) As part of this processing, the web service stores some kind of client server id

4) At some later point in time another app retrieves this id and sends an asynchronous message to the client server

5) The app running on the client server runs some kind of listener waiting for this type of message

6) Once the listener gets the message the app carries out some appropriate processing

I'm not good on firewalls but could the problem with the firewall preventing access to the client not be got around using some security details, like providing the appropriate username/password
xd
Apologies for not replying earlier - have been away on well deserved annual leave.

I was under the impression that Web Services always ran on a server, not the client. How can we run a web-service on the Client Any knowledge or pointers would be much appreciated.
alexsalo
This is doable in a couple of different ways but one problem pops up right away. A firewall will not let you access the client at a future time. The client needs to initiate the conversation before you would be allowed to respond. Also the future message would need to go to an application and not just the clients browser. The clients browser will not recognize incoming messages it did not request.
Accessing a client id from within a web service

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