What is .NET Remoting?

At its fundamental level, .NET Remoting allows two processes within the same or different application domains to communicate with each other in a client-server relationship. In this basic scenario, the server component is a remotable object.

.NET Remoting implements interprocess communication by separating the remotable object from a specific client, server application domain, or particular communication mechanism. As a result, .NET Remoting is flexible and easily customizable.

This abstraction works through the use of two main concepts:

- Channels - Channels provide the transport between remote components. The default channels are TCP and HTTP.
- Formatters - Formatters convert (serialize) objects into a common format the other process (or, in the case of interoperability, platform) can understand. The default formatters are binary and SOAP.

By specifying a channel and a formatter, you can define how you establish communications between a remotable object and its client. The channels specify the communication protocol. The formatters then act as serializers, serializing and de serializing the data objects that pass between the remotable object and the client. The ability to customize these channels and formatters is what allows you to use .NET Remoting for connectivity between .NET Framework applications and Java applications.

.NET Remoting provides more than just communication between processes; you can also use it for links between two or more application components that are in different application domains. To do this, just change the configuration of .NET Remoting to exchange data between the separate application domains. This gives you flexibility to build an application that runs on just one computer but that you can then extend to run in a distributed environment with minimal adjustment to the code.

.NET Remoting also supports two ways for passing data between application components. These are:

- Pass by value (PBV)
- Pass by reference (PBR)

Pass by value involves returning of the data from a remote system call to the client. Pass by reference returns a pointer or reference to the data and the remote server maintains the data's state.

Each method has advantages and disadvantages. The method you choose depends on the type of application you are developing, the data that you want to pass, and the network environment the application must function in.

Passing by reference can offer performance benefits when exchanging large data objects or with distributed systems where network latency slows down pass by value communication. However, if you pass a data object by reference, this makes a remote call to the referenced data object on the server each time the client accesses another field on the object.