http:// the mobile grid concept vicente olmedo technical university of madrid

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The MobileGrid Concept

Vicente OlmedoTechnical University of Madrid

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Contents

Introduction The Akogrimo Project The Next Generation Mobile Grid

Concept The Session Initiation Protocol (SIP)

SIP fundamentals The Session Description Protocol (SDP)

SIP usage for Web Service mobility

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Introduction (1/2)

The Akogrimo EU IST project is aimed to the design and implementation of a Next Generation Mobile Grid.

Concept: Next Generation Mobile Grid (NGMG)

Concept: Mobile Dynamic Virtual Organization (MDVO)

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Introduction (2/2)

NGMG = Mobile Network + Grid Services

Network

AApppplliiccaattiioonn SSeerrvviicceess

Network Middleware

Grid Application Support Services

Grid Middleware Services

Session Initiation Protocol (SIP)Session Initiation Protocol (SIP)

Session Session ManagementManagement

Mobility Mobility SupportSupport

Presence & Presence & ContextContext

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The Session Initiation Protocol (1/4)

Standardized by the IETF in RFC 3261. Signaling protocol targeted to the

management of sessions in IP networks. SIP is independent of the type of session

being managed. Basic messages (methods): REGISTER,

INVITE, ACK, BYE, CANCEL, OPTIONS. Extensible: new methods can be defined

in order to support new functionalities. Signaling entities also defined: User

Agent, Proxy, Registrar.

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The Session Initiation Protocol (2/4)

User registration process

alice@atlanta.comalice@pc33.atlanta.com

bob@biloxi.comRegistraratlanta.com

Location Service Proxyatlanta.com

REGISTER alice@atlanta.com

alice@pc33.atlanta.comalice@atlanta.com

alice@pc33.atlanta.com200 OK

INVITE alice@atlanta.com

QUERY alice@atlanta.com

RESP alice@pc33.atlanta.com

INVITE alice@pc33.atlanta.com

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The Session Initiation Protocol (3/4)

Session establishment and termination

alice@atlanta.com bob@biloxi.comProxybiloxi.com

Proxyatlanta.com

INVITE bob@biloxi.com

INVITE bob@biloxi.com

INVITE bob@biloxi.com100 Trying

100 Trying

108 Ringing

108 Ringing

108 Ringing200 OK

200 OK

200 OK

ACK

SESSION DATA

BYE

200 OK

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The Session Initiation Protocol (4/4)

Message format example

Request Line

Message body

(SDP)

INVITE sip:volmedo@dit.upm.es SIP/2.0

Via: SIP/2.0/UDP 138.4.3.130:3456CallID: a2e3a@138.4.3.130From: sip:villagra@dit.upm.esTo: sip:volmedo@dit.upm.esCseq: 1 INVITEContent-type: application/SDPContent-Length: 117

v=0c=IN IP4 138.4.7.148m=application 8080 HTTP soap+xmla=setup:passivea=wsdl:http://138.4.7.148/service.wsdl

SIP Headers

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Web Services are getting mobile

Network architectures tend to convergence access technology independence is a must.

Architectural design tends to Service Oriented Architectures.

User terminals becoming more and more powerful.

In Grid environments, users themselves can also be resources.

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ws.dit.upm.es

200 OK (SOAP response)

Traditional, fixed scenario

GET http://ws.dit.upm.es/service.wsdl

200 OK (service.wsdl)

POST /method (SOAP request)

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volmedo@dit.upm.es(138.4.7.148)

Mobile, ubiquitous scenario

INVITE volmedo@dit.upm.es

200 OK

(EPR: http://138.4.7.148/service.wsdl)

GET http://138.4.7.148/service.wsdl

200 OK (service.wsdl)

POST /method (SOAP request)

200 OK (SOAP response)

ACK

SIP session establishment

Classical SOAP interaction

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Extending SDP

SDP syntax can be extended by the definition of new attributes.

Request Line

Message body

(SDP)

INVITE sip:volmedo@dit.upm.es SIP/2.0

Via: SIP/2.0/UDP 138.4.3.130:3456CallID: a2e3a@138.4.3.130From: sip:villagra@dit.upm.esTo: sip:volmedo@dit.upm.esCseq: 1 INVITEContent-type: application/SDPContent-Length: 117

v=0c=IN IP4 138.4.7.148m=application 8080 HTTP soap+xmla=setup:passivea=wsdl:http://138.4.7.148/service.wsdl

SIP Headers

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Conclusions

SIP for signaling, SOAP for application. Mobility and ubiquity for Web Services. Web Services can make use of full SIP

capabilities (e.g. session transfer). No need to standardize new SIP

mechanisms. The new SDP attribute needs to be

standardized.

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s.org Thank you!Thank you!

Questions?Questions?

Vicente Olmedo

<volmedo@dit.upm.es>