January 2002

BY BILL PENNINGTON 

Softswitch n 1: a system that disaggregates the functions of a traditional circuit-switched network using centralized software servers controlling distributed media gateways.

While the term is widely used and accepted, there is really no formal, generally agreed upon definition. Perhaps the following is a good summary, but what is a softswitch, really?

This distributed softswitch architecture was introduced for a number of reasons. The first was to break the stranglehold of the traditional switch vendors by disaggregating switching functionality into components that are interconnected via standard, open interfaces and protocols. This would allow service providers to select best in breed components from new innovative vendors. The second reason was to reduce equipment and network costs. This would be achieved through the use of IP technology and by the increased competition brought about by the influx of many new vendors. The third reason was to enable the introduction of new services through the use of �Internet� technology and by opening up the market to new innovative players.

As the softswitch industry matures it will set its sights on local telephone service providers. The capital markets have turned their backs on the market, leaving Incumbent Local Exchange Carriers (ILECs) the primary remaining target market. These carriers derive 80 percent of their revenue from voice services and are not about to risk this revenue stream just for the promise of new technology benefits. Existing subscriber access interfaces, network interfaces, testing, operations, and features will need to be supported by any new technology. A low risk new technology migration path could start with offering enhanced services such as unified messaging, then adding IP toll network interfacing, introducing new access technologies such as VoDSL, and then eventually upgrading the local inter-office network to ATM or IP.

ILECs considering a next-generation switch must look at its capability to provide the features, services, interfaces and operations seamlessly with their existing network while providing a risk free migration path to the introduction of new technology at price points well below traditional legacy switching. Since many ILECs have introduced ATM technology for its QoS capabilities, a next-gen Class 5 switch should be capable of supporting ATM access and trunking in addition to IP. Furthermore, ILECs must ensure that the Class 5 alternative also supports legacy and new enhanced service delivery thru AIN, softswitch protocols, and a robust API. Web-based customer service control and management must be extended to all subscribers, not just those using VoIP.

In order to make a successful transition to next-generation packet-based networks, it is clear that ILECs must address a wide range of issues including operational and captital expenditures, compatibility with circuit-switched networks and the ability to deliver new and enhanced voice and data services. Although softswitch architecture promises to play a critical role in the transition to next-gen, it is only a piece of this complex puzzle. Carriers must execute a measured strategy that enables them to generate revenue from current services while adding enhanced services and expanding their footprint in a cost-efficient and stable manner.

Bill Pennington is chief technological officer for Taqua Systems, Inc.

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