Download Application Layer Network

Network Architecture for
Virtual Network Appliances
Tadashi Okoshi
89831191, [email protected]
Hideyuki Tokuda Laboratory
Digital Media Infrastructure Software Project
Research Abstract

Application Layer Network (ALN)
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Focuses on the home appliances network
Approach in the application layer of network
Provides…
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Communication transparency
through heterogeneous network architectures
Communication continuity
across relocation of hosts and applications
Heterogeneous Communication
App(a)
Mobile
Communication
Heterogeneous
Hosts and Networks
App(b)
Application
App(b)
Relocation
Contents

1.Background
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2.Network Architecture for VNA
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Characteristics & Issues
3.ALN Architecture
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Network Appliance
VNA
Application Layer Approach
Architecture
Design Detail of Mobile Communication
4.Evaluation
5.Conclusion and Future Work
1.Research Background:
Network Appliance

Network Appliance

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Appliance with the functionalities of
collaborative behavior through its network
connectivity.
Factors

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Small-size and powerful processor
Wired/wireless network technologies
Network Appliances
Digital
Camera
with Network
Connectivity
Cellular Phone
with Internet
Connectivity
© Cannon
© NTT DoCoMo
Digital Video
Camera
With A/V
Network
Connection
© Sony
Microwave
with Network
Connectivity
© Sharp
IEEE1394
(A/V Devices)
Ethernet
(LAN)
USB
(PC Devices)
Piconet
(Embedded Wireless)
WaveLAN
(Wireless LAN)
IrDA
(Infrared)
Example Host
with Multiple Network Interfaces
IEEE1394
IrDA
(A/V Devices)
(Infrared)
Ethernet
(LAN)
© Sony
USB
(PC Devices)
Network
Combinational use of
the numerous appliances
on the network
1.Research Background:
Virtual Network Appliance (VNA)
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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
Room(C)
Data Reader
Video Player
Audio Player
“Virutal VCR” VNA
Room(A)
Room(B)
2.Research Focus:
Network for VNA Architecture

(1) Characteristics
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Heterogeneity of connecting hosts
Heterogeneity of network architectures
Mobility
(2) Issues
Sensor Network
(e.g. RS-232C)
LAN (e.g. Ethernet)
22 ℃
Bluetooth
36 ℃
IrDA
Embedded Wireless Network (e.g. Piconet)
IEEE1394
Digital A/V Network (e.g. IEEE1394)
USB, IrDA,
IEEE1394, Ethernet
Mobile Hosts
and Equipments
Host(A)
A
App(a)
B
App(b)
MobileHost(A)
Network (A)
Relocation Relocation
(User)
(Application)
B
Relocation
(Host)
Host(B)
App(a)
A
App(c)
Network (B)
App(b)
MobileHost(A)
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
3.Proposed System:
Application Layer Network
(ALN)
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Network architecture built on the
transport layer
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Goal
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Functionalities
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Communication Transparency
Communication Continuity
Heterogeneous Communication
Mobile Communication
Exploits “Application Layer Approach”
Layers
Layer 7
Layer 6
ISO OSI Reference Model
The Internet (TCP/IP) Model
Application
Layer
Application
Layer
Application
Presentation
Layer
Session
Layer
Layer 5
Transport
Network
Datalink
Physical
Application Layer Network (ALN)
TCP/UDP/IP
IEEE1394
Ethernet
IEEE802.3
Wireless Etc…
IEEE802.11
IrDA
Features of
Application Layer Approach

Communication transparency
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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)
Features of
Application Layer Approach

Communication continuity
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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
Features of
Application Layer Approach
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High Portability
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Zero modification for Layer1-4 protocols
Implementation with code segmentation
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Platform Independent Subsystem
Platform dependent Subsystem
Architecture & Functionalities
Applications
Application Layer
2 Layers in ALN
 HCL
- Communication Transparency
- Provides comm. transport which
ALN
Mobile
Communication Layer (MCL)
is independent of layer1-4.

Heterogeneous
Communication Layer (HCL)
…
Layer
1～4
Network Network
(a)
(b)
…
Network
(c)
Heterogeneous Network Architectures
MCL
- Communication Continuity
- Provides comm. interface which
is continuous across the
relocation of communication
endpoint.
Architecture and Functionalities
Applications
Application Layer
ALN
2 Layers in ALN
 HCL
- Communication Transparency
- Provides comm. transport which
Mobile
Communication Layer (MCL)
is independent of layer1-4.
- Application can communicate
without being aware of the
heterogeneous layer1- 4
networks.
Heterogeneous
Communication Layer (HCL)
…
Layer
1～4
Network Network
(a)
(b)
…
Network
(c)
Heterogeneous Network Architectures

MCL
Architecture and Functionalities
Applications
Application Layer
ALN
Mobile
Communication Layer (MCL)
Heterogeneous
Communication Layer (HCL)
…
Layer
1～4
Network Network
(a)
(b)
…
Network
(c)
Heterogeneous Network Architectures
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.
ALN-Heterogeneous
Communication Layer (HCL)
Communication between Applications
Host(2)
Host(3)
Host(1)
Host(4)
Application
ALN-HCL
L5
L4
L3
L2
IrTTP
IrTTP
TCP/UDP
TCP/UDP
1394 Trans
1394 Trans
IrLMP
IrLMP
IP
IP
1394
1394
IrLAP
IrLAP
Datalink
Datalink
L1
Palm
IrDA
Host Addressing
Ethernet
Ethernet
Communication Endpoint Identifier
TCP/IP
IEEE1394
Routing/Connection
Redirecting
Interface for Applications
HCL Design (1)
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Host Addressing
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Communication Endpoint ID
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ALN-HostAddress for each host
Allocated by hand
Ex. “VAIO-Server-Dad”
(ALN-HostAddress, ALN-PortName)
Port guarantees uniqueness inside a host
Ex. (“VAIO-Server-Dad”, “VODServer”)
Routing
Interface to Applications
HCL Design (2)
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Routing
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Reactive routing protocols for Ad-hoc Network
Interface to Applications
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Virtual Circuit
Datagram
ALN-Mobile Communication Layer
(MCL)
Relocation
Host(1)
Host(2)
Host(3)
A
Host(4)
B
A’
ALN-MCL
L5
L4
ALN-HCL
…
L1
Palm
IrDA
Connection Switching
TCP/IP of Byte Stream
IEEE1394
Guarantee
Consistency
Interface for Applications
Communication between Applications
MCL Design & Mechanisms
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Connection Switch
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Byte Stream Consistency Support
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Dynamic Socket Switching (DSS)
For Virtual Circuit Communication Retainment
Application Layer Window (ALW)
Retransmit of the data in ALW after the relocation
Interface for Applications
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MobileSocket interface
Applications can use one persistent MobileSocket
connection even after the relocation of
communication endpoint
START POINT
Closed
Connected from Client
(DSS-EstablishmentPhase(Server) )
Lost IP address
Implicitly
Suspended
Connected to Server
(DSS-EstablishmentPhase(Client) )
Called suspend()
(send SUSPEND_SIGNAL,
DSS-ExplicitSuspend Phase)
Called resume()
Get IP address
(Reconnect to CH, DSS(Reconnect to CH, DSSImplicitResume Phase) Established ExplicitResume Phase)
Reconnected from MH
(DSS-ImplicitResume Phase)
Called close()
(close connection)
Explicitly
Suspended
reconnected from MH
(DSS-ExplicitResume Phase)
DataSocket broken-pipe
Reconnected from MH
(DSS-ImplicitResume Phase)
Called close()
or timedout
(close connection)
received SUSPEND_SIGNAL
(DSS-ExplicitSuspend Phase)
Called close()
(close connection)
Called close()
(close connection)
Transition trigger
(action)
Called close()
or timedout
(close connection)
Normal Transitions for CH
Normal Transitions for MH
State
Normal Transitions for Client
Normal Transitions for Server
Client
DSS-Establishment Phase
Data
Socket
Control Redirection
Socket ServSocket
Server
Data
Socket
Control Redirection
Socket ServSocket
accept()
connect
Create
Socket
Create
Socket
connect()
accept()
Create
Socket
Create
Socket
Correspondent Host
Mobile Host
Data
Socket
Control Redirection
Socket ServSocket
Redirection
New
Control Redirection
ServSocket
→ DataSocket Socket ServSocket
lose IP
～disconnected～
accept()
Create
Socket
DSS-ImplicitResume Phase
connect()
Create
Socket
Create
Socket
unlock
get IP
connect()
accept()
Create
Socket
unlock
Prototype Implementation
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ALN-HCL
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Platform: Linux-2.2.13
Language: C
Network: TCP/IP, IrDA, Serial+Mux
Server & Library
ALN-MCL
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Language: Java1.1
Jp.ac.keio.sfc.ht.mobilesocket Class Library
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MobileSocket (TCP Mobile Socket)
MobileDatagramSocket (UDP Mobile Socket)
Application
Server
Application
ALN-Port Manager
Route
Manager
Port Table
Routing Table
Main Thread
Client
Application
libHCL
ServerSocket
Route
Exchanger th.
Connection Redirector
Parent th.
Networks
Connection
Redirector
Child th.
Connection
Redirectors
Client Socket
Internal Server th.
Connection
Server th.s
Internal Server Child th.s
ALN Transport Interface
User Level
ALN-HCL-Server
L1-4 (unix_ip)
L1-4 (linux_irda)
L1-4 (unix_serial)
Multiplexer
L1-4 (internal_unix)
Socket(AF_INET)
Socket(AF_IRDA)
Device File
Socket(AF_UNIX)
TCP/IP
IrTTP/LMP/LAP
Com Port
IPC
Ethernet
IrPHY
Serial
Kernel
L1-4 Interfaces (Library)
ALN-MCL Implementation
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User-level library implementation in Java
Compatible with standard Java1.1 Socket API
Additional methods for explicit connection
redirection: suspend() and resume()
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Mobility notification event:

Applicable to mobile applications

MobilityEvent
MobileSocket library itself can migrate with
applications with Java Object Serialization
mechanism
MobileSocket
for Mobile Applications

“Serializable” MobileSocket class
for Mobile Applications and Agents
AppA
MSockA (SocketX)
AppB
Host-A
Object
Serialization
AppA’
MSockA (SocketY)
Host-C
Host-B
4.Evaluations

Comparisons with related works
based on other approaches
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
(1) Communication transparency
(2) Communication continuity
Related Approaches
Communication
Transparency
L5 Application Layer
ALN, Proxies, GIOP
L4
Transport Layer
IP-Masquerade
L3
Network Layer
NAT, IP over
L2
Datalink Layer
L1
Physical Layer
x
Communication
Continuity
ALN, MSOCKS
TCP-R
Mobile IP
Comparisons
(1) Communication Transparency
Comm.Transparency
Heterogeneous Network
Scalability
Mechanism
Code Size
Portability
Adoption for New net.
Further Functionality
Internet Access
Processing at Intermediate Hosts
ALN-HCL
IP Approach
Applicable
Applicable
small
high
easy
large
low
difficult
possible
original
limited
suitable
global
not suitable
Comparisons
(1) Communication Continuity
Comm.Continuity
Virtual Circuit Comm.
Datagram Comm.
MobileIP TCP-R MSOCKS
Limited
OK
MCL
OK
OK
Limited
OK
OK
OK
Layer4
Layer5
Layer5
Implementation
Layer3
Modification for
Layer1-4 Protocols
necessary necessary necessary unnecessary
Optional Software
HA, FA
Mobile Application
Support
No
-
Proxy
-
No
No
Yes
5.Conclusion

Network environment for VNA

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ALN provides

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Heterogeneity of hosts and networks
Mobility
Communication transparency
Communication continuity for applications
Application layer approach

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Applicability for heterogeneous hosts and networks
Enables both virtual circuit and datagram
communication continuity
Simplified and minimized implementation
Effective for mobile applications or agents
Future Work

Communication transparency

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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
Publications
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
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).


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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).