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Much of the ongoing debate over what the converged network of the future
will look like, and how quickly it will take shape, boils down to one key
question: Is the development of converged communications networks more
dependent on new applications and services (such as IP-based voice, the
Web, instant messaging, presence, and more) or on an advanced network
infrastructure to support those new services?
This intriguing "chicken or the egg" question is of far more
than academic interest, especially in the current economic climate of
slower carrier capital outlays and the search for viable business models
by communications application service providers (CASPs). Next-generation
carriers are leveraging solutions based on session initiation protocol
(SIP) to support new services, but they will need SIP-based traffic to
justify those investments. In order to grow and become profitable, CASPs
need to focus their resources on creating and marketing cool new services
like Web-based conference calling and voice-enabled instant messaging
(IM), instead of how to terminate, host, and route those applications.
We believe that this emerging network architecture offers opportunities
for a new category of ASP that we refer to as the converged ASP. Converged
ASPs will be able to generate revenues by focusing on generating and
creating applications -- not on providing the back-end infrastructure for
terminating, routing and hosting those applications. Converged ASPs will
be able to use standard tools and open platforms that will provide them
with management interfaces, reliability, access to databases, protocol
implementations, fault tolerance, and a toolkit of common application
components. The converged ASP can leverage next-generation carriers to
terminate, host, and route its applications.
THE SERVICE DELIVERY ARCHITECTURE
dynamicsoft has outlined a vision of how we believe communications
networks will evolve. We call this vision The Service Delivery
Architecture -- a dynamic model that demonstrates how the
service-generation infrastructure of converged ASPs will work seamlessly
with the new service-delivery infrastructure of converged carriers.
To understand the forces that are creating the Service Delivery
Architecture, we should look first at how the Web has evolved. Though
still far from a mature market, the Web economy has transitioned from
do-it-all service providers such as AOL to one of relentless
specialization, driven by the need to reduce costs and improve time to
market. This specialization has resulted in distinct niches that include
consumer- or business-focused Web sites; application developers;
application platforms; Web hosting companies; retail ISPs; and backbone
ISPs that aggregate Web traffic.
The forces of specialization are now at work on the converged
communications landscape. Thus AT&T, the classic vertical monolith,
has given way to a deregulated telecom environment that is now further
decomposing into very specific layers. These niches consist of
customer-facing converged ASPs, third-party application developers,
application platforms, hosting companies, and converged carriers. These
segments are defined as follows.
Converged ASPs
Converged ASPs are responsible for building applications used by business
or consumers. The converged ASP owns the development of the value-added
application, and the customer relationship. In many cases, such an ASP may
not even have technical staff.
Application Developers
Rather than develop the application in-house, the ASP can rely on
third-party application developers who have expertise in the use of
industry standard application platforms and who can develop the
application with direction from the ASP. This model has proven highly
successful on the Web, where scores of developer companies build sites for
companies with good ideas but little time for technology.
Application Platform Providers
Application platform providers, another new niche in the communications
business model, are equipment vendors who build the environment on which
the applications live. They provide the critical pieces needed by all
applications -- protocol implementations, reliability, fault tolerance,
toolkits, and so on.
Hosting Companies
Hosting companies purchase (and resell to their customers) termination
services from carriers. Hosting companies typically have no gateways or
softswitches, but focus on providing the infrastructure for third parties
to deploy new applications. This would typically include application
servers, media servers, conferencing servers, databases, and a SIP proxy
routing infrastructure to connect these components to each other, and to
carriers that provide PSTN connectivity.
Converged Carriers
Converged carriers provide critical connectivity to the PSTN, in addition
to transport services and QoS (quality of service) standards. A converged
carrier is an IP-based carrier that support both legacy telephony and
converged applications on its own network. These carriers will use
hierarchies of SIP proxy servers for security, routing and accounting when
connecting to other IP-based networks, and softswitches for connecting to
legacy PSTN networks.
The dynamic nature of the Service Delivery Architecture suggests that
new service generation (leveraging application developers and application
platforms) will drive the installation of network infrastructure by
converged carriers. That will, in turn, fuel even more services. Carrier
networks will focus on the infrastructure needed to support externally
developed (and possibly externally hosted) applications.
Because application providers are separate from carriers,
standards-based interfaces will be key to success in the converged
network. SIP will be the standard for the converged network, due to its
interoperability, extensibility, and ability to deliver revenue-generating
converged services while replicating existing Class 4 and Class 5
telephony applications.
THE ROLE OF THE SOFTSWITCH
What role do softswitches play in this converged network architecture? One
traditional view holds that softswitches contain all the functionality
needed for converged networks, since they can serve as application as well
as switching platforms. Our viewpoint is different. Softswitches are,
first and foremost, access platforms. They provide critical connectivity
to the PSTN in a highly scalable and reliable fashion. Placing
applications on the softswitch ties access to services; the assumption is
that these services are available only to those users who enter the
carrier network through the softswitch.
It also assumes that the owner of the softswitch is the owner of the
application. These assumptions are not true when one considers the
converged ASP model we've been discussing. Converged ASPs will want to
host and run their own applications, outside of any particular carrier
network. Separating the applications from access also improves scalability
(since complex applications can consume resources needed for access) and
reliability (a faulty application could crash a softswitch and eliminate
access for people not even using the application), while making it much
easier to introduce new services.
This new model offers a compelling blueprint for helping both
traditional carriers and converged ASPs transition from traditional
telephony services to converged services. Service providers, for example,
can deliver revenue-generating, market-ready services such as prepaid,
toll/tandem and PBX now -- while laying the foundation for converged
services such as instant messaging, presence, and customized routing for
converged services.
SERVICE DELIVERY FOR CONVERGED NETWORKS
2001 will see a new generation of true carrier-class communications
application servers reach the market that leverage Web programming tools
such as servlets, CGI (Common Gateway Interface), XML, and Java, rather
than arcane and proprietary telephony programming tools. While these
application servers will support carrier-built services, their real
promise is in their ability to execute a broad variety of
independently-written applications.
In fact, the latest generation of carrier-class application servers may
well feature a complete separation between application developers and
application deployers, using the same types of tools used in commercial
web servers to achieve this separation. These enhancements will radically
streamline the time and expense needed to develop useful and innovative
services. For converged ASPs, the benefits of such plug-and-play
applications are clear. They can focus their finite resources where it
matters: creating, marketing, and billing for new applications.
The advent of new IP-based services applications will drive the
creation of converged networks, and will be spurred by the arrival of
highly scalable application platforms that support independently-designed
applications. Next-generation carriers will route and deliver these
applications and will fuel the growth for yet more new services. The
result: great new services for consumers and businesses, faster time to
market, and the revenue-generating services that will spell
differentiation -- and success -- for communications service providers.
Jonathan Rosenberg is chief scientist at dynamicsoft, Inc. For more
information, please visit www.dynamicsoft.com.
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