Communication

1. Communication Chapter 2

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

3. Layered Protocols (2) 2-2 • A typical message as it appears on the network.

4. Data Link Layer 2-3 • Discussion between a receiver and a sender in the data link layer.

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

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

7. Conventional Procedure Call • Parameter passing in a local procedure call: the stack before the call to read • The stack while the called procedure is active

8. Client and Server Stubs • Principle of RPC between a client and server program.

9. Steps of a Remote Procedure Call • Client procedure calls client stub in normal way • Client stub builds message, calls local OS • Client's OS sends message to remote OS • Remote OS gives message to server stub • Server stub unpacks parameters, calls server • Server does work, returns result to the stub • Server stub packs it in message, calls local OS • Server's OS sends message to client's OS • Client's OS gives message to client stub • Stub unpacks result, returns to client

10. Passing Value Parameters (1) 2-8 • Steps involved in doing remote computation through RPC

11. Passing Value Parameters (2) • Original message on the Pentium • The message after receipt on the SPARC • The message after being inverted. The little numbers in boxes indicate the address of each byte

12. Parameter Specification and Stub Generation • A procedure • The corresponding message.

13. Doors • The principle of using doors as IPC mechanism.

14. Asynchronous RPC (1) 2-12 • The interconnection between client and server in a traditional RPC • The interaction using asynchronous RPC

15. Asynchronous RPC (2) 2-13 • A client and server interacting through two asynchronous RPCs

16. Writing a Client and a Server 2-14 • The steps in writing a client and a server in DCE RPC.

17. Binding a Client to a Server 2-15 • Client-to-server binding in DCE.

18. Distributed Objects 2-16 • Common organization of a remote object with client-side proxy.

19. Binding a Client to an Object Distr_object* obj_ref; //Declare a systemwide object referenceobj_ref = …; // Initialize the reference to a distributed objectobj_ref-> do_something(); // Implicitly bind and invoke a method (a) Distr_object objPref; //Declare a systemwide object referenceLocal_object* obj_ptr; //Declare a pointer to local objectsobj_ref = …; //Initialize the reference to a distributed objectobj_ptr = bind(obj_ref); //Explicitly bind and obtain a pointer to the local proxyobj_ptr -> do_something(); //Invoke a method on the local proxy (b) • (a) Example with implicit binding using only global references • (b) Example with explicit binding using global and local references

20. Parameter Passing 2-18 • The situation when passing an object by reference or by value.

21. The DCE Distributed-Object Model 2-19 • Distributed dynamic objects in DCE. • Distributed named objects

22. Persistence and Synchronicity in Communication (1) 2-20 • General organization of a communication system in which hosts are connected through a network

23. Persistence and Synchronicity in Communication (2) • Persistent communication of letters back in the days of the Pony Express.

24. Persistence and Synchronicity in Communication (3) 2-22.1 • Persistent asynchronous communication • Persistent synchronous communication

25. Persistence and Synchronicity in Communication (4) 2-22.2 • Transient asynchronous communication • Receipt-based transient synchronous communication

26. Persistence and Synchronicity in Communication (5) • Delivery-based transient synchronous communication at message delivery • Response-based transient synchronous communication

27. Berkeley Sockets (1) • Socket primitives for TCP/IP.

28. Berkeley Sockets (2) • Connection-oriented communication pattern using sockets.

29. The Message-Passing Interface (MPI) • Some of the most intuitive message-passing primitives of MPI.

30. Message-Queuing Model (1) 2-26 • Four combinations for loosely-coupled communications using queues.

31. Message-Queuing Model (2) • Basic interface to a queue in a message-queuing system.

32. General Architecture of a Message-Queuing System (1) • The relationship between queue-level addressing and network-level addressing.

33. General Architecture of a Message-Queuing System (2) 2-29 • The general organization of a message-queuing system with routers.

34. Message Brokers 2-30 • The general organization of a message broker in a message-queuing • system.

35. Example: IBM MQSeries 2-31 • General organization of IBM's MQSeries message-queuing system.

36. Channels • Some attributes associated with message channel agents.

37. Message Transfer (1) • The general organization of an MQSeries queuing network using routing tables and aliases.

38. Message Transfer (2) • Primitives available in an IBM MQSeries MQI

39. Data Stream (1) • Setting up a stream between two processes across a network.

40. Data Stream (2) 2-35.2 • Setting up a stream directly between two devices.

41. Data Stream (3) • An example of multicasting a stream to several receivers.

42. Specifying QoS (1) • A flow specification.

43. Specifying QoS (2) • The principle of a token bucket algorithm.

44. Setting Up a Stream • The basic organization of RSVP for resource reservation in a distributed • system.

45. Synchronization Mechanisms (1) • The principle of explicit synchronization on the level data units.

46. Synchronization Mechanisms (2) 2-41 • The principle of synchronization as supported by high-level interfaces.