Programmable Architecture for the Creation and Seamless Control of Hybrid Services

Programmable Architecture for the Creation and Seamless Control of

Hybrid Services

Constant Gbaguidi

Swiss Federal Institute of Technology (Lausanne)

Creation and Control of Hybrid Services

Institute for computer Communications and Applications

Swiss Federal Institute of Technology, LausanneCommunication Systems Division (SSC)

2

Outline• Problem Statement

– Need for a creation and control architecture, with well-defined service components

• Our approach– Service-centricity, as opposed to network- and end-system-centricity

– Programmability: changing the behavior of a system through an API

– Smooth migration from existing infrastructures to more “futuristic” ones

– Use of tools that can be understood by Telecom as well as Internet people

• Case studies– Voice-Access-to-Content, Closed User Group (CUG)

• Related Work

• Conclusion




3

Scope of Hybrid Services

Telecommunication services

Internet servicesHybrid Services

ConferenceIN VPNVoice MailCall ForwardingMobility

ConferenceInternet VPNEmail and VoicemailChat (IRC)Content services (Web)Electronic commerce

Voice Access to ContentTelecommutingTeleconferenceIntegrated VPN

• Hybrid services are not re-implementations of existing services

• They allow access to services already implemented on either telecommunication or IP networks

• They allow unique implementation of services, which can still be accessed from any network

• They pave the road to the provision of future services that do not rest on only one network




4

Problem Statement

• How to create and control hybrid services?– Control:

• Provision of a service binding layer that permits passing service control information across networks (Today we have interoperability at the media transfer and media control layers)

– Creation: • Specification of components out of which services can be built (The components must

make sense to both Telecom and Internet communities)

• Mapping of the components onto the service system elements

IP network PSTN

H.323 gatewayCaller Callee

Freephone service logic




5

An Overview of Our Solution

ServiceCreation

Environment

Internet

PSTN(and N-ISDN)

CellularNetwork

API

API: Application Programming Interface

Java Service Layer

Programmability




6

API

API: Application Programming Interface

Java Service Layer

ServiceCreation

Environment

Programmability

Terminal Network Node Control Server Gateway

SwitchRouterWireless LAN NodeGSM Base Station

H.323 gatewayFirewall

IN Service Ctrl PointH.323 gatekeeperDHCP serverDNS

WorkstationSmart phone

An Overview of Our Solution (cont’d)




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Service Creation Environment Service Factory

Service Instance

Beans Archive

1. Identify service components

SS SSSS

ST/S2

ST/S1

SN/S1

SC/S2

SC/S1

SG/S1

Controller Controller Controller Controller


Java Service Layer

Service binding Service binding Service binding Service binding

CT/Si: Subsystem on Terminal for Service #iCN/Si: Subsystem on Network node for Service #iCC/Si: Subsystem on Control server for Service #ICG/Si: Subsystem on Gateway for Service #iSS: Service Subsystem

3. Build the binding

layer

Architecture of Our Solution

2. Download the components




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1. Service Modeling: A Way to Identify Components

A Service is composed of features, each of which is associated with an object model. Classes in the models are the sought components

Customer Service

Feature

defines *

Charging Call control Connectivity User Interaction

involvesinteracts with

Address Translation

Security

Inheritance

Composition

Object class

Association class

Key:




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1. Example: Address Translation

• End-system is a generic concept that embraces terminals, gateways, information converters, multipoint control units, etc.

• The user makes use of a device (e.g., a Smart Card) that has an address

• The user may have a higher level address (e.g., email address)

• The user can bind addresses with one another

Device Device Address

User Address Binding

has1 1

1

manages

uses1

*

End-system

*

*User Address

Device Address

Address

User Address

1

1

has

Inheritance

Composition

Object class

Association class

Key:




10


Service Instance

Beans Archive


SS SSSS

ST/S2

ST/S1

SN/S1

SC/S2

SC/S1

SG/S1



Java Service Layer




layer






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2. Component Download

0. put persistent component c: C

on server Web serverService instance

Controller

1. execute(C c, URL url)

2. get c

3. configure underlying element




12


Service Instance

Beans Archive


SS SSSS

ST/S2

ST/S1

SN/S1

SC/S2

SC/S1

SG/S1



Java Service Layer




layer






13

3. Service Binding Layer

System element interface

Enterprise components (e.g., RMI<->CORBA,

EJB)

Java RMI

Binding components(e.g., security, download)

Element

Element {openConnection,pauseConnection,

resumeConnection,releaseConnection,bindConnections,

transferConnection,handleEvent

}

e.g., TAPI, CallPath API, SS7

API, IN API




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Element

Java Service Layer

Trigger-Event-Source

Trigger-Event-Listener(implements methods to handle the events caught)

Element

Network Node Gateway Control Server Terminal

Inheritance

3. A Way to Interface with Elements

Interruptions, APIs, SNMP, H.323, IN




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1. fires

TriggerEvent

2. goes to

3. fires CnxAttemptEvent

CnxFailEvent6. fires

6. fires

7. goes to 4. goes to

5. creates

CnxCompleteEvent

7. goes to

8. creates

Service component

Event

Java Service Layer

Element

ConnectionFactory

Connection

ConnectionBinding

TriggerEventListener

Event Source

3. A Way to Interface with Elements (cont’d)




16


Service Instance

Beans Archive


SS SSSS

ST/S2

ST/S1

SN/S1

SC/S2

SC/S1

SG/S1



Java Service Layer




layer






17

Implementation Test-bed

• + Most elements of the test-bed can detect special services, by detecting prefixes in the numbers dialed

• - APIs existing on the elements are not easily customizable from an application

PABX H.323GW IP Network

Siemens Hicom 112

H.323GK

ISDN BRI

RADVision Elemedia H.323 stack

Java Service Layer

PABX controller GK controller Term. controller




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Voice-Access-to-Email


Siemens Hicom 112

Java Service Layer

H.323GK

ISDN BRI

RADVision

PABX controller GK controller Server controller

Accommodating server

Email server




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Voice-Access-to-Email (cont’d)

• Start retrieving the mails : Email Retriever

• As long as nothing has come– play waiting message : User Interaction

• Parse the received mail : Email Parser – remove useless header fields (e.g., route information)

– remove useless tags (<FONT>, <BODY>, etc.)

• Convert the parsed file into speech: Microsoft Speech API (Java wrapper, JNI)

• Play the speech file over the network: Elemedia H.323 stack

• ~30s to read an email




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H323 Call factory

Incoming H.323 messages

Outgoing H.323 messages

Call instances

Application

Email Retriever

Email Parser

Text-to-speech

Converter

User Interaction

Email Server

Voice-Access-to-Email (cont’d)




21

Voice-Access-to-W3

H323 Call factory

Incoming H.323 messages

Outgoing H.323 messages

Call instances

Application

Web site Retriever

HTML Parser

Text-to-speech

Converter

User Interaction

Web Server




22

Voice-Access-to-W3: HTML Parser

• Replace a link by an announcement like “Press 234 if you wanna learn more about this topic”

• Remove applet information

• Remove scripts

• A dedicated language would be a suitable solution but then all pages would have to be re-written!




23

Closed User Group

A B C D


Siemens Hicom 112

Java Service Layer

H.323GK

ISDN BRI

RADVision

CUGS controller

CUG Server

Term. controller

E F

Feature: Confidential information passing between F and C while in a session with A, B, D and E




24

Learnings

• The proposed architecture can be used to enhance the service offerings of current platforms

• To fully take advantage of the architecture, we need APIs for the platform elements

• Service composability within the architecture has been illustrated

• Java is a good candidate




25

Related Work in the Internet

• GeoPlex (AT&T)

– 5 programmable elements:• Cores: mission-critical

databases and functions

• Hops: e.g., routers

• Gates: entrances to the GeoPlex network

• Stores: directories, event reports

• Peers: GeoPlex-enabled devices

• Internet-dependent, although some of the APIs can be re-used for other elements

SecureSecuretrusted-domaintrusted-domain

boundaryboundary

ConsumerConsumerNetworkNetwork

ConsumerConsumerNetworkNetwork

HopHop

StoreStore

TelephoneTelephoneNetworksNetworksTelephoneTelephoneNetworksNetworks

HopHop

HopHop

InternetInternetInternetInternet

ee ClientClientPeerPeer

ClientClientPeerPeer

Extended Extended NetworkNetwork

VideoVideoSvcSvc

CoreCore

GateGate

GateGate

GateGate

GateGate

GateGateGateGate

GateGate

GateGate

ee ClientClientPeerPeer


eeClientClientPeerPeer


Our solution is more generic and applicable to all technologies




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Related Work in Telecommunications

• Intelligent Network (IN)– dumb terminals

– services as compositions of functional building blocks

– service logic controlled by Service Control Points (SCP)

• no service creation environment standardized

• building blocks are heavily defined

• limited distribution (functional approach!)

SSP SSP

SCP

(1) We propose a service creation environment based on a platform-independent language (i.e., Java)

(2) We use an object-oriented technique to find and specify service components




27

Related Work in Telecommunications (cont’d)

• Telecommunications Information Networking Architecture (TINA)

– goal: enhance the IN with distributed processing and integrate service provision and management

• heavyweight connection management (connection-oriented networks)

• building of service logic not emphasized

Serv. Sess. Mgr

Net. Cnx Mgr

Net. Elt. Mgr Net. Elt. Mgr

Computationalobject

Our solution provides a simple connection model and a technique to determine generic service components




28

Related Work in Telecommunications (cont’d)

• XBIND (Columbia University, NY)– same objectives as TINA, but with a

service-centric vision: programmability of end-systems considered

• ATM-oriented

• lack of a service model

(1) Our solution is both past- and future-proof: no specific technology in mind(2) We provide a service model that helps find service components using an object-oriented technique

Serv. Sess. Mgr

Net. Cnx Mgr

Net. Elt. Mgr

Net. Elt. Mgr

Device Mgr

Camera Mgr

Display Mgr




29

Related Work on Hybrid Services

• Computer-Telephony Integration (CTI)

– goal: be able to place and control telephone calls from a computer

– “IN” for corporate networks• deployment at the edge of the network, e.g., in enterprise networks: complex

services need also to look into the network

PABX

CTI LinkOur solution enables CTI to

look into the network in order to implement

sophisticated services




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Related Work on Hybrid Services (cont’d)

• PSTN and Internet Interworking (PINT)

– enable a telephone call from an IP terminal to the PSTN

• data is transported over the PSTN

• no service control from the initiating IP terminal

(1) Our solution extends data transport to any network, not only the PSTN(2) Service control can be performed from the IP network

SSP SSP

SCP

Internet (HTTP/CGI)

Web server

PSTN

PSTNIP




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Summary• Legacy systems are unlikely to disappear overnight: the future will

be hybrid

• Main contributions– Thorough assessment of the benefits in integrating Telecoms and Internet

– A service-centric and programmable architecture

– A method for determining service components

– A method for interfacing with service system elements, including existing networks and mechanisms

• We provide a unified way to interface with existing networks

• Our method enables smooth introduction of new services




32

Summary (cont’d)

• Future directions– Inter-provider interface

• how to make service control layers of different operators talk to one another?

– Management• how to manage the behavior of a service?

• how to allocate resources for a service and control this allocation?

• how to solve feature interactions?

– Performance• what do we need to do in order to build a system that performs as

reliably as the PSTN?




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Java Service Layer

Summary (cont’d)

• Future directions– Extension to wireless networks

• what are the effects of the characteristics of wireless networks on the design of the components?

BSSSoftware Radio




34

References

• J. P. Hubaux, C. Gbaguidi, S. Koppenhoefer and J. Y. Le Boudec, “The impact of the Internet on Telecommunication architectures”, Computer Networks, Feb. 1999

• C. Gbaguidi, J. P. Hubaux, G. Pacifici and A. N. Tantawi, “Integration of Internet and Telecommunications: An architecture for hybrid services”, JSAC, Sept. 1999.

• C. Gbaguidi, J. P. Hubaux, M. Hamdi and A. N. Tantawi, “A programmable architecture for the provision of hybrid services”, IEEE Comm. Mag., July 1999.

• C. Gbaguidi, S. Znaty and J. P. Hubaux, “Multimedia resources: An information model and its application to an MPEG2 video codec”, JNSM, Sept. 1998.

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Programmable Architecture for the Creation and Seamless Control of Hybrid Services