What is RPC Implementation?

Remote Procedure Call (RPC) is a protocol that allows a program running on one computer to execute procedures or functions on another computer across a network. The calling program doesn't need to understand the underlying network details, making remote operations appear as local function calls.

RPC abstracts the complexity of network communication, enabling distributed applications to interact seamlessly across different systems and networks.

Applications of RPC

RPC is widely used in various systems and applications:

• Active Directory service − Windows uses RPC for domain authentication and directory services.

• MMC terminals − Microsoft Management Console relies on RPC for remote administration.

• DCOM components − Distributed Component Object Model is built on top of RPC infrastructure.

• System utilities − Tools like Windows Computer Management and Registry Editor use RPC to manage remote systems.

RPC Implementation

The RPC implementation involves multiple components working together to provide transparent remote procedure execution:

Step-by-Step Process

Step 1 − The client program makes a local procedure call to the client stub, passing parameters normally. The client is unaware this will become a remote call.

Step 2 − The client stub performs parameter marshalling, packing the parameters into a network message format and sending it to the transport layer.

Step 3 − The transport layer adds appropriate headers and transmits the message across the network to the destination server.

Step 4 − The server's transport layer receives the message and forwards it to the server stub for processing.

Step 5 − The server stub unmarshalls the parameters and makes a local procedure call to the actual server program, which executes normally without knowing it's serving a remote request.

Step 6 − The server procedure completes execution and returns results to the server stub, just like any local procedure call.

Step 7 − The server stub marshalls the return values into a message and hands it to the transport layer for transmission back to the client.

Step 8-10 − The response travels back through the network, gets unmarshalled by the client stub, and finally returned to the original client program as if it were a local procedure call.

Key Features

• Transparency − Remote calls appear identical to local procedure calls.

• Marshalling/Unmarshalling − Automatic conversion of parameters and return values for network transmission.

• Stub procedures − Handle the complexity of remote communication on both client and server sides.

Conclusion

RPC implementation provides a transparent mechanism for executing remote procedures by using client and server stubs that handle parameter marshalling, network communication, and result unmarshalling. This architecture enables distributed applications to function as if all components were running locally.