Describe the term Channel in .Net Remoting

In .Net Remoting, an application use Channel to send message to another application which is runing in different domain or process. Before sending message, Channel converts message into appropriate format like XML or binary format. The channel that carries message(Mashalled parameter) can use protocal like TCP and HTTP. Channel can be HTTPChannel and TCPChannel. The HTTPChannel use soapFormatter to serialize messages into the XML format using SOAP protocal. Using SOAP method allows the client to call method on the remote object that might not be using .Net framework. The TCPChannel use binaryFormatter to serialize message into binary stream.

Describe the type of remotable objects in .Net Remoting.

Marshal-by-value-objects - When client calls a method on marshal-by-value-object, the remoting system creates a copy of this object and passes the copy to the client application domain. The copy hence received can handle any method call in client domain. Using Marshal-by-value-object reduces resource consuming trip across network.
Marshal-by-reference-object - When client calls a method on Marshal by reference object, the remoting system create proxy object in the caller application that contains the reference of all method and properties of the object.

What are the remotable and non-remotable objects in .Net Remoting.

The remotable objects are the objects which can be distributed accross domains, can be used with domain. The non-remotable objects are the objects which can't be distributed accross domains. In distributed system, if an object is very big, we can make it non-remotable object.

What security measures exist for .NET Remoting in System.Runtime.Remoting?

None. Security should be taken care of at the application level. Cryptography and other security techniques can be applied at application or server level.