Success At The Edge
BY SALLY BAMENT
Carriers recognize that in order to prosper in todayï¿½s
telecommunications market, they must touch customers directly ï¿½ not only
with attractive rates or with superior voice quality, but also with new and
innovative services that reflect the forward-thinking and demanding
communications consumer of the 21st century. Although a large subscriber
base is already using some advanced services offered by carriers, there are
more inventive services yet to be created and deployed. Itï¿½s the creation
of these new, value-added services that holds the greatest promise for
carriers in their efforts to meet the demands of residential and business
users, while also increasing their profitability.
Migrating Services To The New Public Network
As the cornerstone of profitability in the old PSTN, the basic feature
set of Class 5 custom calling services is also vital to carriersï¿½ success
in the New Public Network. However, with exorbitant equipment, operational,
and recurring license costs, coupled with proprietary interfaces and long
deployment or upgrade timeframes, legacy equipment for delivering new
services to the edge is no longer considered a desirable transport choice.
Todayï¿½s network edge equipment must support the popular Class 5 features
of the existing PSTN that sustain carrier revenues, including caller ID,
call-waiting and voice mail, and regulated services (such as local number
portability, CALEA, and E911), while also taking into consideration future
enhanced services to generate new profits.
So whatï¿½s the answer for carriers who need to streamline operations,
deliver enhanced services and push service revenues to the limits?
Enter the Next-Generation Network ï¿½ a packet-based, decoupled
infrastructure that enables applications and services to be created and
deployed more rapidly and managed more cost effectively.
Aside from the existing CLASS, Centrex, and regulatory services,
next-generation technology allows a whole new breed of services to be
developed without the traditional barriers to service deployment. Not only
will service providers be able to easily deploy and/or deliver lucrative
multimedia services like unified messaging, video conferencing, and
Web-casting, but simplified service creation tools will also enable feature
provisioning by IT departments, network operation administrators, and even
The Foundation Of A Service-Based Architecture
Built on a distributed architecture, next-generation technology
decouples service creation, call control, and service transport, giving
service providers direct control over service creation and service delivery.
As the foundation of the transport infrastructure, media gateways convert
traffic between TDM and packet networks, essentially replacing legacy
equipment such as Class 4 and 5 circuit switches. Softswitches manage the
access and service creation layers using various protocols ï¿½ H.248, MGCP,
or SIP ï¿½ to direct media gateways, setting up and controlling calls across
broadband packet-switched and narrowband circuit-switched networks.
To justify the adoption of broadband Class 5 services, however, service
providers require a critical component ï¿½ the ability to easily provision
value-added services. Tired of facing long waits and expensive licenses for
service upgrades and provisioning of new services with ï¿½big ironï¿½
equipment, carriers need to deploy solutions that provide an open and
manageable architecture where future innovative voice services can be
introduced quickly to the market. Positioned at the core of the service
creation layer, application servers coupled with the softswitch provide such
a solution. The application server essentially carries out the service logic
and specific instructions needed to deliver features to subscribers.
Open APIs and programming languages and standards such as XML and Java
further facilitate rapid service creation. Such open service creation
environments also allow service providers to utilize third-party
applications, broadening the existing range of applications that the PSTN
The Economic Benefits Of Next-Generation Networks
Beyond next-generation technologyï¿½s ability to create and deliver edge
services, it also provides an unprecedented cost advantage when compared to
legacy infrastructures. Next-generation networks allow service providers to
manage their networks more efficiently and less expensively ï¿½ with typical
savings of 40 percent or more in rack space, power consumption, and
The economic benefits of a packet-based access solution are further
extended to its extreme density and scale advantage. By aggregating multiple
co-located or geographically distributed media gateways over an ATM or IP
core network, a large virtual switch can be created to scale the number of
ports far above legacy equipment port capacity. For example, a single
softswitch can manage multiple media gateways, increasing the number of
concurrent end-to-end packet-based calls, while delivering service to
millions of provisioned subscriber lines. By and large, only one signaling
gateway is necessary to support this virtual switch configuration,
minimizing the need for multiple and costly SS7 signaling links, point
codes, and application servers.
The virtual switch capabilities of a next-generation network also
simplify network planning, as service providers can provision services from
one or a few centralized locations over IP connections rather than at
multiple POPs in every service region.
Multiple Applications from A Single Platform
Whether deployed in local or long-distance access networks, todayï¿½s
packet technologies are responsible for building a faster, more reliable,
and more profitable network that is capable of delivering multiple
applications to customers over a common infrastructure.
Packet-based edge solutions facilitate high-margin business voice
services such as PBX trunking. Voice calls can be delivered to a media
gateway from a corporate PBX by means of a T-1 unbundled network element (UNE)
and switched back to an ILEC or onto a long-distance network. For
enterprises demanding higher bandwidth service delivery, carriers can also
leverage the technology benefits of high-speed ATM all the way to the
customersï¿½ premises by deploying ATM-based integrated access devices (IADs).
In these applications, the media gateway supports voice over ATM,
interworking with ATM-based IADs that concentrate voice and data traffic
directly onto a high-speed ATM access or long-distance network. With
standard line-side signaling, the more popular media gateways today are
compatible with a number of intelligent third-party IADs that provide
subscriber features, call progress tones, and digit collection.
While service providers have traditionally viewed broadband (DSL in
particular) as a lucrative high-performance delivery mechanism for data
services, broadband is also regarded as a promising medium for voice
services ï¿½ and with good reason. The broadband market represents a
tremendous opportunity for carriers who can bundle voice services with a
range of high-speed data services using next-generation equipment. The
Yankee Group estimates that the DSL market alone will reach 16.7 billion
businesses and residential users by 2006. By integrating standard protocol
support such as MGCP, H.248, and SIP, network elements including media
gateways, IADs, and DSLAMs can be controlled by the softswitch, eliminating
the need for costly Class 5 switches and specialized VoDSL gateways.
Consolidating voice and data traffic onto the same DSL access link, service
providers can support more subscribers with existing infrastructures, while
gaining tremendous profit margins ï¿½ often of 60 percent or more. Add to
this customized business or residential voice features, such as conference
bridging, CENTREX, voice VPN, and PBX extension to remote employees, and the
profit potentials of a packet-based access network are even more impressive.
In spite of the migration toward next-generation architectures, there are
many carriers that still favor traditional legacy-based services, such as
two-wire POTS and T-1 based services. To address interoperability with
legacy TDM Digital Loop Carriers (DLCs), some next-generation media gateways
provide a GR-303 IDT interface, allowing carriers to continue serving POTS
subscribers seamlessly. Next-generation DLCs utilize Broadband Loop
Emulation Service (BLES) to provide broadband voice access, while the
softswitch delivers Class 5 and Primary Line services, as well as service
The voice over cable (VoCable) market is growing at a rapid pace as well.
Most cable operators have already upgraded and expanded their networks to
offer customers more channels and enhanced services. VoCable solutions that
use softswitches enable traditional and enhanced voice services over
existing hybrid fiber-coaxial. Leveraging industry standards, the softswitch
network-based service agents negotiate IP telephony calls between
cable-served subscribers, the PSTN and other IP network-served subscribers
or services. To ensure interoperability, security, and quality of service in
VoCable applications, softswitches and media gateways should comply with
Cable Labs PacketCable specifications for voice services.
Keeping Pace With Next-Generation Technology
As telecommunications and networking technologies continue to evolve,
service providers must continue to meet the day-to-day demands of serving
their customers, relieving network congestion, and trimming operating costs.
Coupled with the need to accelerate the time-to-market of new services to
stay competitive ï¿½ or simply to keep up with those offered by the
competition ï¿½ todayï¿½s New Public Network presents carriers with
formidable challenges. Packet-based, next-generation architectures provide
the solution ï¿½ by provisioning enhanced and value-added services in the
network and delivering them on the edge, all with a significant return on
Sally Bament is vice president of marketing at Convergent Networks, a
company that manufactures next-generation, carrier-class voice switching
solutions. She has over 18 yearsï¿½ marketing and engineering experience in
networking communications. She can be reached at [email protected].
Check out Convergent Networks at www.convergentnet.com.
To The January 2002 Table Of Contents ]