Java Einfhrung

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Lecture IKR Universität Stuttgart Telecommunicatio
n Software Engineering
Organisation of Networks
May 22, 2006 Stephan Rupp
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth RMI JINI J2ME CORBA Web
Services Universal Plug Play
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Fig. 3-1 Distribution of functions - direct
control vs. remote control
Case 1 Direct Control Procedure Calls and
Context definition within the system
Case 2 Remote Control Communication and Context
need to be defined in both systems
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Fig. 3-2 Communication by exchange of messages
Sender
Receiver
System A
System B
Communication by exchange of messages
Context ?
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Fig. 3-3 Communication within a system - Symbian
OS Client-Server Framework
Server-Thread
Client-Thread
Context ?
Response
Request
Server
User Privileges
Message
Kernel Privileges
Kernel
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Fig. 3-4 Example Client calls server function
Server
Client
x f1(a,b,c)
Request
ServiceL(aMessage)
aMessage.Complete(x)
Response
Context message type for a procedure call on the
server
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Fig. 3-5 Example Client call including data
transfer
Server
Client
y f2(p,q,r)
Request
ServiceL(aMessage)
q
aMessage.ReadL()
aMessage.WriteL()
r
aMessage.Complete(x)
Response
Context exchange pointers to read and write data
between threads
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Fig. 3-6 Example Context includes framework API
for client-server relations
Server
Client
RMessage Function() Complete() ReadL() WriteL()
CServer
CSession ServiceL()
1..n
DSession
Note
Kernel
has a
Context Framework API
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Fig. 3-7 Distribution of functions between
different systems
Client, User Agent
Server, User Agent
Systems contain software for distributed
computing, such as clients, servers or user agents
System B
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth RMI JINI J2ME CORBA Web
Services Universal Plug Play
11
Fig. 3-8 Overlay networks by groups of user agents
Logical networks
User agent
User agent
Physical networks
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Fig. 3-9 The anatomy of a user agent
UA_ID
User Agent
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Fig. 3-10 Discovery Updates and Relations
Local User Agent
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Fig. 3-11 Establish a communication link
local user agent
remote user agent
in
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth RMI JINI J2ME CORBA Web
Services Universal Plug Play
16
Fig. 3-12 JXTA Protocols
Local Peer
Remote Peer
Standard Services
Core Protocols
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Fig. 3-13 The discovery phase in JXTA
Local Peer
Rendezvous Peer
Router Peer
Local Peer
Methods getConnectedPeers()
getConnectedRdvPeers()
Firewall/NAT
Relay Peer
Local Peer (Edge Peer)
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth RMI JINI J2ME CORBA Web
Services Universal Plug Play
19
Fig. 3-14 Bluetooth Service Discovery by SDP
Service Discovery Application
Client Application
Server Application
Service Record
SDP Client
SDP Server
SDP Service Discovery Protocol UUID
Universally Uniform Identifier (used as Service
Attributes)
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Fig. 3-15 Bluetooth Service Records
Service Record (List of Service
Attributes) ServiceRecordHandle ServiceClassIDList
ServiceRecordState ServiceID ProtocolDescriptionL
ist BrowseGroupList LanguageBasedAttributeIDList S
erviceInfoTimeToLive ServiceAvailability Bluetooth
ProfileDescriptorList DocumentationURL ClientExecu
tionURL IconURL ServiceName ServiceDescription Pro
viderName
...
...
...
E.g. Value or Value list of UUIDs (Typ Data
Element Sequence)
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth Java RMI JINI J2ME CORBA Web
Services Universal Plug Play
22
Fig. 3-16 Java-RMI (Remote Method Invocation)
Client Java interface
Server implements Client Java interface
Application Software
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Fig. 3-17 JINI - discovery and download of client
proxies
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Multicast Request Protocol
Lookup Service
Lookup Service
Discovering Entity
Lookup Service
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Multicast announcement protocol
Discovering Entity
Discovering Entity
Lookup Service
Discovering Entity
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Unicast discovery protocol
Lookup Service
Discovering Entity
Service
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Join
Discovery
Service Provider
Lookup Service
Join
Service Proxy
Service
Service-Item
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Lookup
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth RMI JINI J2ME CORBA Web
Services Universal Plug Play
30
Fig. 3-18 The structure of J2ME
Mobile Device
CLDC
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Fig. 3-19 The J2ME CLDC Generic Connection
Framework
Connection
StreamConnectionNotifier
InputConnection
StreamConnection
OutputConnection
ContentConnection
DatagramConnection
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth RMI JINI J2ME CORBA Web
Services Universal Plug Play
33
Fig. 3-20 Evolution of Computer Programming
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Fig. 3-21 Distributed Computing
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Fig. 3-22 CORBA
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Fig. 3-22 CORBA
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Fig. 3-23 Reconstruction of the client from
context description
Context-Definition
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Fig. 3-24 Relations of Web Services Components
Gives a reference to the description of the
service
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Fig. 3-25 The Principle of UDDI
White PagesGeneral information about the
organisation offering the service
Yellow PagesInformation sorted by certain
criteria
A Web Service is characterized by a URL
pointing to its WDSL description.
Green PagesMethods and Parameters valid for the
service
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth RMI JINI J2ME CORBA Web
Services Universal Plug Play
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Universal Plug Play Devices and Services
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Universal Plug Play Architecture
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A challenge for Plug Play Home Networks
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How to organise Home Networks
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Use of domain models and meta-information
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A framework for the organisaion of networks
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Organisation of Networks
1 Basic Principles Communication and
Context Service Discovery and organisation of
networks 2 Some Concepts in Practice JXTA Blueto
oth RMI JINI J2ME CORBA Web
Services Universal Plug Play
The END