Thank a lot to everyone. I will try to change the other method to receive the data in order to avoid the character limited problem occured.

Below are 2 posible solution/suggestion from online friends.
  • On SAP there is obivously a HTTP process running in order for you to send the GET request - firstly, if SAP is running this process then there is no reason why it cannot read a POST request as well. Secondly, rather than using HTTP why not communicate to the server using a custom port and transfer your data that way?


  • One thing I do know is that SAP can read text files. Why not place all the data you want to transfer within a text file that is accessible from both the IIS and SAP servers. Then send a GET request to the SAP server including the filename / location of the text file and its data.