1. Network Architecture for Virtual Network Appliances Tadashi Okoshi 89831191, slash@mag.keio.ac.jp Hideyuki Tokuda Laboratory Digital Media Infrastructure Software Project

2. Research Abstract Application Layer Network (ALN) Focuses on the home appliances network Approach in the application layer of network Provides … Communication transparency through heterogeneous network architectures Communication continuity across relocation of hosts and applications

3. Application App(a) App(b) Heterogeneous Hosts and Networks App(b) Relocation Heterogeneous Communication Mobile Communication

4. Contents 1.Background Network Appliance VNA 2.Network Architecture for VNA Characteristics & Issues 3.ALN Architecture Application Layer Approach Architecture Design Detail of Mobile Communication 4.Evaluation 5.Conclusion and Future Work

5. 1.Research Background: Network Appliance Network Appliance Appliance with the functionalities of collaborative behavior through its network connectivity. Factors Small-size and powerful processor Wired/wireless network technologies

6. Network Appliances Cellular Phone with Internet Connectivity Digital Camera with Network Connectivity Digital Video Camera With A/V Network Connection Microwave with Network Connectivity © Cannon © NTT DoCoMo © Sony © Sharp

7. Piconet (Embedded Wireless) IrDA (Infrared) Ethernet (LAN) USB (PC Devices) IEEE1394 (A/V Devices) WaveLAN (Wireless LAN)

8. Example Host with Multiple Network Interfaces Ethernet (LAN) USB (PC Devices) IrDA (Infrared) IEEE1394 (A/V Devices) © Sony

9. Combinational use of the numerous appliances on the network Network

10. 1.Research Background: V irtual N etwork A ppliance ( VNA ) Achieves combinational use based on functional components of the appliances Combination is abstracted as Virtual Network Appliance (VNA) Ex. “ Virtual VCR ” VNA Audio/Video data play-back

11. Room(A)Room(B) Room(C) “ Virutal VCR ” VNA Data Reader Video Player Audio Player

12. 2.Research Focus: Network for VNA Architecture (1) Characteristics Heterogeneity of connecting hosts Heterogeneity of network architectures Mobility (2) Issues

13. 22 ℃ 36 ℃ Digital A/V Network (e.g. IEEE1394) Embedded Wireless Network (e.g. Piconet) LAN (e.g. Ethernet) Sensor Network (e.g. RS-232C) Bluetooth IrDA IEEE1394 USB, IrDA, IEEE1394, Ethernet Mobile Hosts and Equipments

14. Network (A) Network (B) MobileHost(A) Host(B) Host(A) B Relocation (User) A App(b) App(a) BB App(c) A Relocation (Host) MobileHost(A) A App(b) App(a) Relocation (Application ) App(a)

15. 2.Research Focus: Network Architecture for VNA (1) Characteristics (2) Issues Applications ’… Communication transparency through the coexisting multiple network architectures Communication continuity across the relocation of hosts and applications

16. 3.Proposed System: A pplication L ayer N etwork (ALN) Network architecture built on the transport layer Goal Communication Transparency Communication Continuity Functionalities Heterogeneous Communication Mobile Communication Exploits “ Application Layer Approach ”

17. Session Layer Application Layer Presentation Layer Application Layer Physical Datalink Network Transport Layer 5 Layer 6 Layer 7 ISO OSI Reference ModelThe Internet (TCP/IP) Model TCP/UDP/IP Ethernet IEEE802.3 Wireless IEEE802.11 IEEE1394IrDA Etc … Application Layer Network (ALN) Application Layers

18. Features of Application Layer Approach Communication transparency Applicability for diverse Layer1-4 networks by Zero-Modification for Layer1-4 protocols ⇒ Characteristic: Heterogeneity of networks Simplified and Minimized Mechanisms by using functionalities of Layer1-4 protocols ⇒ Characteristic: Heterogeneity of hosts (Especially for those with limited capability i.e., PDAs, Home appliances)

19. Features of Application Layer Approach Communication continuity Achieve {Virtual Circuit, Datagram} communication continuity by using Layer-4 transport protocols Friendliness with application applicable for mobile applications and agents ⇒ characteristics: Mobility Applicability for diverse Layer1-4 networks by Zero-Modification for Layer1-4 protocols (Continuity across the heterogeneous networks) ⇒ characteristics: Heterogeneity of networks

20. Features of Application Layer Approach High Portability Zero modification for Layer1-4 protocols Implementation with code segmentation Platform Independent Subsystem Platform dependent Subsystem

21. Architecture & Functionalities 2 Layers in ALN HCL - Communication Transparency - Provides comm. transport which is independent of layer1-4. MCL - Communication Continuity - Provides comm. interface which is continuous across the relocation of communication endpoint. ALN Heterogeneous Communication Layer (HCL) Layer 1 ～ 4 Applications … Heterogeneous Network Architectures Network (a) Mobile Communication Layer (MCL) Network (b) Network (c) … Application Layer

22. Architecture and Functionalities 2 Layers in ALN HCL - Communication Transparency - Provides comm. transport which is independent of layer1-4. - Application can communicate without being aware of the heterogeneous layer1- 4 networks. MCL ALN Heterogeneous Communication Layer (HCL) Layer 1 ～ 4 Applications … Heterogeneous Network Architectures Network (a) Mobile Communication Layer (MCL) Network (b) Network (c) … Application Layer

23. Architecture and Functionalities ALN Heterogeneous Communication Layer (HCL) Layer 1 ～ 4 Applications … Heterogeneous Network Architectures Network (a) Mobile Communication Layer (MCL) Network (b) Network (c) … Application Layer 2 Layers in ALN HCL MCL - Communication Continuity - Provides comm. transport which is continuous across the relocation of communication endpoint. - Application can communicate continuously after the relocation.

24. ALN-Heterogeneous Communication Layer (HCL) IrLAP IrLMP IrTTP IrDATCP/IPIEEE1394 Application ALN-HCL IrLAP IrLMP IrTTP Ethernet IP TCP/UDP Ethernet IP TCP/UDP Datalink 1394 1394 Trans Datalink 1394 1394 Trans Host(1) Host(2)Host(3)Host(4) L4 L3 L2 L1 L5 Palm Palm Communication between Applications Communication Endpoint Identifier Routing/Connection Redirecting Interface for Applications Host Addressing

25. HCL Design (1) Host Addressing ALN-HostAddress for each host Allocated by hand Ex. “ VAIO-Server-Dad ” Communication Endpoint ID (ALN-HostAddress, ALN-PortName) Port guarantees uniqueness inside a host Ex. ( “ VAIO-Server-Dad ”, “ VODServer ” ) Routing Interface to Applications

26. HCL Design (2) Routing Reactive routing protocols for Ad-hoc Network Interface to Applications Virtual Circuit Datagram

27. ALN-Mobile Communication Layer (MCL) IrDATCP/IPIEEE1394 ALN-HCL Host(1) Host(2)Host(3)Host(4) L5 L4 L1 Palm Palm Communication between Applications ALN-MCL … B B A A A’A’ A’A’ Relocation Connection Switching Guarantee of Byte Stream Consistency Interface for Applications

28. MCL Design & Mechanisms Connection Switch Dynamic Socket Switching (DSS) Byte Stream Consistency Support For Virtual Circuit Communication Retainment Application Layer Window (ALW) Retransmit of the data in ALW after the relocation Interface for Applications MobileSocket interface Applications can use one persistent MobileSocket connection even after the relocation of communication endpoint

29. Established Implicitly Suspended Explicitly Suspended Closed Connected to Server (DSS-EstablishmentPhase(Client) ) Connected from Client (DSS-EstablishmentPhase(Server) ) Lost IP address Get IP address (Reconnect to CH, DSS- ImplicitResume Phase) Reconnected from MH (DSS-ImplicitResume Phase) suspend() Called suspend() (send SUSPEND_SIGNAL, DSS-ExplicitSuspend Phase) resume() Called resume() (Reconnect to CH, DSS- ExplicitResume Phase) reconnected from MH (DSS-ExplicitResume Phase) received SUSPEND_SIGNAL (DSS-ExplicitSuspend Phase) DataSocket broken-pipe Reconnected from MH (DSS-ImplicitResume Phase) close() Called close() (close connection) close() Called close() or timedout (close connection) close() Called close() (close connection) close() Called close() or timedout (close connection) Normal Transitions for CH Normal Transitions for MH Normal Transitions for Client Normal Transitions for Server Transition trigger (action) START POINT State

30. ClientServer Data Socket Control Socket connect accept() ControlSocket port, AuthenticationSEED1 accept() connect() ACK AuthenticationSEED1 DSS-Establishment Phase Redirection ServSocket RedirectionServer port, Next_SEED Data ALW ACK Data Socket Control Socket Redirection ServSocket Create Socket

31. Control Socket connect() accept() ACK, ControlSocket port, AuthenticationSEED3 accept() connect() ACK AuthenticationSEED3 DSS-ImplicitResume Phase Redirection ServSocket → DataSocket RedirectionServer port, Next_SEED Data Socket Control Socket Redirection ServSocket New Redirection ServSocket Next_SEED unlock READ_COUNTER unACKed Data retransmit ～ disconnected ～ lose IP get IP Create Socket Control Socket connect() accept() ACK, ControlSocket port, AuthenticationSEED3 accept() connect() ACK AuthenticationSEED3 DSS-ImplicitResume Phase Redirection ServSocket → DataSocket RedirectionServer port, Next_SEED Data Socket Control Socket Redirection ServSocket Mobile Host Correspondent Host New Redirection ServSocket Next_SEED unlock READ_COUNTER unACKed Data retransmit ～ disconnected ～ lose IP get IP Create Socket

32. Prototype Implementation ALN-HCL Platform: Linux-2.2.13 Language: C Network: TCP/IP, IrDA, Serial+Mux Server & Library ALN-MCL Language: Java1.1 Jp.ac.keio.sfc.ht.mobilesocket Class Library MobileSocket (TCP Mobile Socket) MobileDatagramSocket (UDP Mobile Socket)

33. Client SocketServerSocket L1-4 Interfaces (Library) Main Thread Route Manager Routing Table ALN-Port Manager Port Table Internal Server th. Internal Server Child th.s Networks Route Exchanger th. Connection Redirector Parent th. Connection Redirector Child th. Connection Redirectors Client Application Server Application Connection Server th.s L1-4 (unix_serial) Multiplexer L1-4 (unix_ip)L1-4 (linux_irda)L1-4 (internal_unix) Socket(AF_INET)Socket(AF_IRDA)Device File TCP/IP Ethernet IrTTP/LMP/LAP IrPHY Com Port Serial Socket(AF_UNIX) IPC ALN-HCL-Server Application libHCL ALN Transport Interface Kernel User Level

34. ALN-MCL Implementation User-level library implementation in Java Compatible with standard Java1.1 Socket API Additional methods for explicit connection redirection: suspend() and resume() Mobility notification event: MobilityEvent Applicable to mobile applications MobileSocket library itself can migrate with applications with Java Object Serialization mechanism

35. MobileSocket for Mobile Applications “ Serializable ” MobileSocket class for Mobile Applications and Agents AppB Host-B Host-A AppA AppA ’ Object Serialization MSockA (Socket X ) MSockA (Socket Y ) Host-C

36. 4.Evaluations Comparisons with related works based on other approaches (1) Communication transparency (2) Communication continuity

37. Related Approaches Application Layer Transport Layer Network Layer Datalink Layer Physical Layer L1 L2 L3 L4 L5ALN, Proxies, GIOP IP-Masquerade NAT, IP over x Communication Transparency Communication Continuity ALN, MSOCKS TCP-R Mobile IP

38. Comparisons (1) Communication Transparency ALN-HCLIP Approach Comm.Transparency Heterogeneous NetworkApplicableApplicable Scalabilitylimitedglobal Mechanism Code Sizesmall large Portabilityhighlow Adoption for New net.easydifficult Further Functionality Internet Accesspossible original Processing at Intermediate Hosts suitablenot suitable

39. Comparisons (1) Communication Continuity MobileIP TCP-R MSOCKS MCL Comm.Continuity Virtual Circuit Comm. Limited OK Limited OK Datagram Comm. OK OK OK OK Implementation Layer3 Layer4 Layer5 Layer5 Modification for necessary necessary necessary unnecessary Layer1-4 Protocols Optional Software HA, FA - Proxy - Mobile Application No No No Yes Support

40. 5.Conclusion Network environment for VNA Heterogeneity of hosts and networks Mobility ALN provides Communication transparency Communication continuity for applications Application layer approach Applicability for heterogeneous hosts and networks Enables both virtual circuit and datagram communication continuity Simplified and minimized implementation Effective for mobile applications or agents

41. Future Work Communication transparency Optimization of Implementation QoS-aware transport for applications Application layer functionalities at the intermediate hosts (i.e., Accounting, Active processing) Communication continuity Disconnected operation with application-side customization

42. Publications Okoshi, T., Tobe, Y. and Tokuda, H.: MobileSocket: Library based Continuous Operation Support for Java Applications, 第 2 回プログラミングおよび応用のシス テムに関するワークショップ (SPA ‘ 99), 日本ソフトウエア科学会 (1999). Okoshi, T., Mochizuki, M., Tobe, Y. and Tokuda, H.: MobileSocket: Toward Continuous Operation for Java Applications, In Proceedings of IEEE 8th International Conference on Computer Communications and Networks (ICCCN), IEEE Communication Society, pp. 50-57 (1999). Okoshi, T., Mochizuki, M., Tobe, Y. and Tokuda, H.: MobileSocket: Session Layer Continuous Operation Support for Java Applications, 情報処理学会論文誌, Vol.40, No.6, pp.2573-2584 (2000). 大越匡, 中澤仁, 田村陽介, 望月祐洋, 戸辺義人, 西尾信彦, 徳田英幸 : VNA ：仮想 情報家電の実現へ向けて, 第 59 回情報処理学会全国大会 (1999). 中澤仁, 大越匡, 望月祐洋, 徳田英幸 : VNA 構築用ライブラリの設計と実装, 第 59 回情報処理学会全国大会 (1999).