1. Communication

2. Layers, interfaces, and protocols in the OSI model.
Layered Protocols (1)
2-1
Layers, interfaces, and protocols in the OSI model.

3. A typical message as it appears on the network.
Layered Protocols (2)
2-2
A typical message as it appears on the network.
Layering provides transparency and interoperability

4. Functionalities of Layers
Physical: Standardizes signaling interfaces
Data link: Organizes bits to form frames, detects and corrects transmission errors
Network layer: Routing (Internet protocol [IP])
Transport layer: Reliability (retransmission, ordering of packets)
Session layer: Dialog control and synchronization
Presentation layer: Formats of messages and records
Application layer: Specific to applications (HTTP, FTP)

5. Client-Server TCP
2-4
Normal operation of TCP.
Transactional TCP.

6. Middleware Protocols Resides in the application layer
Provides protocols for supporting generic services
Authentication protocols
Commit protocols (Atomicity)
Distributed locking
Slightly adapted reference model

7. An adapted reference model for networked communication.
Middleware Protocols
2-5
An adapted reference model for networked communication.

8. Remote Procedure Call Send/receive do not conceal communication
Birrel and Nilsen designed first RPC protocol
Allowing programs to invoke procedures on other machines
Caller invokes the procedure and is suspended
Parameters are passed to callee, which executes the process and returns results
Caller continues with its execution
Hides communication