Parlay
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Parlay is an open API for the telephone network (fixed and mobile.)
- See also: Parlay is a kind of gambling bet.
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Parlay Overview
The Parlay Group is a technical industry consortium (founded 1998) that specifies APIs for the telephone network. These APIs enable the creation of services by organizations both inside and outside of the traditional carrier environment. In fact, it is hoped that services can be created by IT developers, rather than telephony experts.
Important Parlay APIs include: call control, conferencing, user interaction (audio and text messaging), and charging. The APIs are specified in the CORBA Interface definition language and WSDL. The use of CORBA enables remote access between the Parlay gateway and the application code. A set of Java mappings allow the APIs to be invoked locally as well. A major goal of the APIs is to be independent of the underlying telephony network technology (e.g. CDMA vs GSM vs landline SS7).
In 2003 the Parlay Group released a new set of web services called Parlay X. These are a much simpler set of APIs intended to be used by a larger community of developers. The Parlay X web services include Third Party Call Control (3PCC), Location and simple payment. The Parlay X specifications complement the more complex yet powerful Parlay APIs. Parlay X implementations are now (Sept 2004) in commercial service from BT and Sprint.
Parlay work historically stems from the TINA effort. Parlay is somewhat related to JAIN, and is currently (early 2003) completely unrelated to the Service Creation Community.
The Parlay Group works closely with ETSI and 3GPP, the Parlay specifications are co-published by all three bodies. Within 3GPP Parlay is part of Open Services Architecture, so we often use the term Parlay/OSA.
Parlay Technology
The objective of Parlay/OSA is to provide an API that is independent of the underlying networking technology and of the programming technology used to create new services. As a result the Parlay/OSA APIs are specified in UML. There are then a set of realizations, or mappings, for specific programming environments:
- CORBA/IDL
- Java
- WSDL
Parlay Framework
It is important for a telecom network operator to know that any applications using the Parlay API cannot affect the security or integrity of the network.
The role of the Parlay/OSA Framework is to provide a way for the network to authenticate applications using the Parlay/OSA API. The Framework also allows applications to discover the capabilities of the network, and provides management functions for handling fault and overload situations.
Parlay APIs
The Parlay service APIs, are how application make telephone calls, or query the location of a person (or terminal) or charge for the download of a ringtone.
Implementing Parlay
The Parlay/OSA specifications define an API, they do not say how the API is to be implemented.
The typical Parlay/OSA implementation adds a new network element - the Parlay/OSA Gateway. The Gateway implements the Framework. It may implement the individual service APIs, or may interact with other network elements such as switches to provide individual service capabilities such as call control or location. Some vendors treat the Parlay/OSA Gateway as a stand-alone network element (e.g., the Ericsson NRG), others include this function in an IN Service Control Point (e.g., the Telcordia OSP).
Parlay and Web Services
The Parlay X APIs define a set of simple telecom-related Web services. Parlay X Version 1, published in May 2003, defines web services for:
- Third Party Call, Network Initiated Third Party Call, Send SMS, Receive SMS, Send Message, Receive Message, Amount Charging, Volume Charging, User Status and Terminal Location
References
Web
- Parlay Group: http://www.parlay.org.
- Download specifications http://www.parlay.org/specs/index.asp
Printed
Journal Articles
- Moerdijk, A-J; & Klostermann, L. Opening the Networks with Parlay/OSA: Standards and Aspects Behind the APIs. IEEE Network. May/June 2003, 58-64.
Books
- Jain, Ravi; Bakker, John-Luc; & Anjum, Farooq (2004). Programming Converged Networks: Call Control in Java, XML and Parlay/OSA, Wiley Interscience, 2004. ISBN 0471268011
News
- Let your mouse do the dialling (26 May 2004)., Financial Times, IT Review p.3.
- BT plc (26 Apr 2004). BT Wholesale Web Call Connect service: http://www.btplc.com/News/Pressreleasesandarticles/Corporatenewsreleases/2004/nr0426.htm Press Release.