Software interoperability in the NGN Service layer Dave
Software interoperability in the NGN Service layer Dave Penkler CTO Open. Call, HP © 2004 Hewlett-Packard Development Company, L. P. The information contained herein is subject to change without notice
Presentation Outline • Why Software Interoperability for NGN • Preliminaries − NGN Service layer − Software Portability versus Interoperability • Protocols versus API’s • APIs and Protocols in the service layer • Conclusion 10/20/2021 HP 2
Why Software Interoperability for NGN • Interoperability from the user’s perspective: − Ability to create, use and share information and services on different devices with software from different vendors over multiple networks and service providers. • • The value is in the applications Application innovation happens elsewhere: − Standard developers can hardly anticipate all useful applications and business models − The cost, complexity and delay incurred by striving for convergence at the protocol level will likely kill aspiring NGN business cases. • Programmability of the network = Application innovation for NGN − Clear separation of network and application functionality − Defining abstractions of network capabilities as software interfaces − The interface specifications are open and implementations testable for interoperability − Software functions can be invoked transparently across the network − Restore end to end transparency: protocol & SW interoperability 10/20/2021 HP 3
Next Generation Network Architecture Common Service Infrastructure (e. g. IMS) Management Functions Adapted from ITU-T FGNGN-FRA Network Application Interface Service stratum Network Resources & Capabilities I/F Transport User Profile Functions Customer Functions Access Functions UNI Network Attachment Control Functions Access Transport Functions functions Service User Profile Functions Service and Control Functions Transport Control Functions Media Handling Functions Other networks Gateway Functions Core. Transport Functions functions Edge Functions NNI Transport stratum Control Access Network Independence 10/20/2021 Application Functions Media Transport Network Independence Management HP 4
Software Portability vs Interoperability • Software portability − Code that can be deployed and executed on different systems with the same behaviour • Source code: portability ensured by compiler and libraries • Binary code: portability ensured by application binary interface • Network code: (Code that can be sent over a network and executed at the destination) portability ensured by run-time environment (eg: Java, ECMAscript, XML scripts) • Software interoperability − Code developed to one side of an interface specification that can interact as expected with heterogeneous implementations the of the other side either locally or remotely. 10/20/2021 HP 5
Application Programming Interfaces vs Protocols • • NGN supports the delivery of end-user services through application servers, rather than directly embedding services as capabilities in the control protocols Protocols define what bits are sent on the wire between 2 entities – Technology neutral. APIs are defined in terms of the operations and data-structures exchanged between 2 software entities either locally or remotely. API’s are implemented as a service interface to protocols or as a higher level interface usefully combining a number of lower level or remote peer functions. Applications interact with users, network resources and with one another through API’s NGN and IMS standards development is primarily done at the protocol level. Adopting all IP and IETF protocol standards is not enough to enable end to end network transparency. − SIP protocol specs for IMS are already horribly complicated • Web Services: A viable technology neutral way to define interfaces and achieve software interoperability over the network. 10/20/2021 HP 6
API complexity trade-off Remote Invocation Application Number of Programmers Level of Abstraction Application Programming Simplicity Service Enabler API Application Function Service Building Block API Implementation Complexity of API Level of Expressivity of API High Level Protocol API Middleware Low Level Protocol API Protocol Implementation Transport Network Functions 10/20/2021 HP 7
APIs and Protocols in the Service Layer Network applications and capabilities, exposed via XML and Web Service interfaces (e. g. Parlay. X, OMA web services). Network Application Layer Interactive Voice & Video Applications Instant Group Communication Applications Next-Generation Messaging Applications Frameworks for Network Applications Network Resources & Capabilities exposed as API’s or protocols Network Resources Identity Media Processing, Management Subscriber Media Control, Profile Media Storage Authentication Management Authorisation Core Network 10/20/2021 IMS Core Network Billing & Rating Circuit Switched Core Network HP User Information Management (presence, contact list, location) Device Capabilities Common frameworks for service provisioning and management External ASPs & IT Applications in service provider and terminal domains Packet Switched Core Network 8
Conclusion • To enable innovation the NGN must be programmable from the edge. • Expose network resources, capabilities and applications as standard API’s • End to end network transparency − Simple protocols − Facilitate protocol and software interoperability • User expects things to work the same everywhere • Software interoperability is key − necessary but not sufficient 10/20/2021 HP 9
10/20/2021 HP 10
- Slides: 10