is an open API
for the telephone
network (fixed and mobile.)
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.
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:
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.
The Parlay service APIs are how an application makes a telephone call, queries the location of a person (or terminal), or charges for the download of a ringtone.
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, AePONA Causeway, HERIT Parlay/Parlay X Gateway), 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
- Parlay Group: http://www.parlay.org.
- Download specifications http://www.parlay.org/en/specifications/
- Telecommunications Information Networking Architecture Consortium: http://www.tinac.com/
- Moerdijk, A-J; & Klostermann, L. Opening the Networks with Parlay/OSA: Standards and Aspects Behind the APIs. IEEE Network. May/June 2003, 58-64.
- Unmehopa, Musa; Vemuri, Kumar; & Bennett, Andy. Parlay/OSA: From Standards to Reality. John Wiley, 2006. ISBN 0-470-02595-6
- Jain, Ravi; Bakker, John-Luc; & Anjum, Farooq (2004). Programming Converged Networks: Call Control in Java, XML and Parlay/OSA,. Wiley Interscience, 2004. ISBN 0-471-26801-1
- Mueller, Steve. APIs And Protocols For Convergent Network Services. McGraw-Hill, 2002. ISBN 0-07-138880-X
- Zuidweg, Johan. Next Generation Intelligent Networks. Artech House, 2002. ISBN 1-58053-263-2
- Let your mouse do the dialling (26 May 2004)., Financial Times, IT Review p.3.
- BT plc (26 April 2004). BT Wholesale Web Call Connect service: http://www.btplc.com/News/Pressreleasesandarticles/Corporatenewsreleases/2004/nr0426.htm Press Release.
- Aepona Ltd. provides OSA/Parlay Gateway and Parlay X System: http://www.aepona.com
- HERIT Inc. HERIT provides OSA/Parlay Gateway, Parlay AS and Parlay X System : http://www.herit.net