Network Computing is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

SOTAs: The Telephony Code: Page 7 of 12

In addition. enterprise application platform vendors like BEA, IBM and Oracle al-ready support Parlay in their "carrier" product lines, and it's likely that one or more of those tools will bring some of that functionality into the corporate space, dragging the Parlay interfaces along with them.

The Parlay consortium developed the core Parlay specification in conjunction with the European Telecommunications Standards Institute (ETSI) and the Third Generation Partnership Project (3GPP), the oversight body for 3G digital-cellular technology. The core Parlay interfaces form the API layer of the 3GPP Open Service Architecture (OSA) and are generally referred to as Parlay/OSA APIs. These APIs are intended to be portable across multiple development environments, are documented for use within CORBA and JAIN environments, and include a WSDL definition.

Separately, there's also a subset specification, called Parlay/X, which describes a lighter set of APIs that are optimized for use with Web service interfaces in particular. Whereas Parlay/OSA provides asynchronous access to numerous low-level functions, Parlay/X provides synchronous access to a much smaller number of functions.

However, the Parlay/X dictionary maps quite well to the kinds of functions that corporate CTI developers might want to use, with high-level functions for call control, conferencing, presence, messaging, address book management and so forth; there are also functions that are more suitable for traditional carrier networks, such as functions to manage ring tones and billing information. All in all, the spec provides a fairly straight mapping to most of the services that an IT application developer might want. It would also be very nice to have a single Web CIT interface that worked with devices and users on local and carrier networks simultaneously. All this makes Parlay/X an interesting specification, even if it is not yet widely used in corporate telephony envi-ronments.

One problem with the Parlay model is that it is heavily layered. In those cases where OSA provides the network-native application interface (as is the case with 3G cellular networks), Parlay/OSA simply exists as a programmable service. But in other cases, Parlay support is typically provided by a gateway of some kind. Since Parlay/X repre-sents a subset of the Parlay/OSA APIs, it is also usually implemented as a gateway to the full Parlay/OSA system. This means that Parlay/X can be a gateway to Par-lay/OSA, which is itself a gateway to the native telephony network.