What methods are there to send read/ write a file from one machine to another?

Using asp.net what non http / ftp methods are there to read a file from one machine and write it back from another?

For example i have an image on machine A called test.JPG. Machine B should be able to grab a copy of test.JPG generate a thunmbail and send it back to Machine A.

I've looked at the following solutions but unsure which if it's architecturally sound

Machine A

Set up a WCF web service with read / write operations

Machine B

Set up a WCF service to read and write files from the WCF service on machine A

Part of the problem is that Machine B needs to know when there are files on Machine A to be processed. What kind of setup do i need on both machines to enable this? Initially i am thinking of polling for files on Machine A.

I am unsure of the above setup so please help me improve it, particularly if WCF is suitable for this开发者_开发问答 kind of work.

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If copying files is the only thing you need to do, you might be able to save yourself some trouble and use pre-written software. I'm thinking of software that's designed to replicate files between load-balanced web servers.