Because only the arrival of the frame back at the client is important, not its contents, the server needs not put any particular information in it. It lets you write programs that follow the normal prcedure call model-but, instead of invoking normal procedures, it lets you invoke procedures that run a remote machine. The RPC mechanism hides the lower-level networking details from your applications. By following the procedure call model, you write and call a remote procedure just as easily as writing and calling a normal procedure. RPC lets you create distributed programs by providing a mechanism to call remote procedures.
Remote procedures are similar to normal procedures.
But, where a normal procedure excutes on the local machine, a remote proceure executes on a remote machine. The codes here are written in C language with BSD socket, which include client and server two parts. After the server receive the data from the client via xserve, it stores it into file ok.data , in which there are the same bytes as that in proj2.data1 after finishing the transmission process. About RPC, you can input integers and arithmetic sign according to the format given by the client, then you can get the calculating result on the client screen got from the server. The client and the server communicate each other via the xserve.