World Telecom Labs (WTL) was established in 1997—with headquarters in Brussels Belgium—and is a manufacturer of intelligent switches and VoIP equipment. WTL focuses its attention on the worldwide service provider market, and claims an installed base of hundreds of thousands of voice ports that are switching billions of minutes of VoIP traffic using WTL equipment. Its flagship switching product is named the IPNx, which is installed by more than 100 network operators in over 50 countries, and has repeatedly won competitive VoIP technical trials.
WTL markets a wide range of switching products, including VoIP-to-TDM switches, signaling gateways, and softswitches. The unique element of the WTL architecture is that it delivers a series of different platforms that are all based upon the same core software. The switching core and applications, such as call detail recording, least-cost routing and prepaid services are delivered as a softswitch (the SoftIVR product), a class 4 switch/media gateway (the IPNx product), and a media/signaling gateway (the SoIP product). Included in all of these products is their patent-pending Network Optimization Protocol (NOP), which can be used with any SIP or H.323 traffic.
The WTL product line consists of three hardware platforms: the PVx, consisting of a server only; the SoIP Gateway, a PCI chassis with plug-in cards; and the IPNx, a compact PCI (cPCI) chassis with plug-in cards. All share the same operating software. The PVx is a no-slots, server-only platform, which is used to deliver IP-only applications. It is used for Soft IVR, WTL’s softswitch product. It also forms the basis for the NOP Packet Voice Xcellerator which is a standalone VoIP optimization appliance.
The high-end products—the SoIP Gateway and the IPNx—share similar hardware platforms. The SoIP is a compact, high-performance SS7-to-IP gateway, designed to allow VoIP operators to add VoIP connectivity to legacy switches and thus extend the life of existing Class 4/5 switches. The gateway supports both SIP and H.323 and up to 32 E1 trunks. It has capacity for up to 960 simultaneous VoIP calls. The SoIP uses a smaller, lower capacity PCI chassis that accommodates up to four plug-in cards. The hardware is designed as a carrier-class product with a number of fault-tolerant features built in, including multiple fail-safe disks, power supplies, and fans.
The IPNx is a multifunction product comprising a SIP and H.323-compatible softswitch; a signaling gateway supporting SS7, ISDN, SIP, and H.323 signaling; a high-capacity, high-reliability media gateway; and an application server for prepaid, interactive voice response (IVR), callback, 800-number, and other applications. The IPNx runs on a Sun SPARC processor board running the Solaris Operating System, which controls the operation of the IPNx, manages the operation of the plug-in interface and resource cards, and runs the applications.
The architecture has been designed to allow the WTL software to be independent from the hardware that is used. The WTL software has been designed as a three-layer model, with the functions in each layer isolated from those above or below, and accessed through defined Application Programming Interfaces (APIs). The Upper layer provides application support; the Middle layer manages the ports, protocols, and other resources, including the NOP algorithm; and the Bottom layer interfaces with the processing and interfacing hardware. The benefit of this design is that changes can be made in one part of the product without major effects on the rest. In addition, all WTL products support exactly the same Upper and Middle Layers. Product differences are handled by the Bottom Layer, which is the only place where an awareness of the hardware is required.
Further details on the World Telecom Labs product and architectures can be found at www.wtl.be. Our next tutorial will continue our examination of vendors’ architectures.
Copyright Acknowledgement: © 2006 DigiNet ® Corporation, All Rights Reserved
Mark A. Miller, P.E. is President of DigiNet ® Corporation, a Denver-based consulting engineering firm. He is the author of many books on networking technologies, including Voice over IP Technologies, and Internet Technologies Handbook, both published by John Wiley & Sons.