Intelligent Networks: An architectural overview

In the last few years, the Internet has become the dominant
driving force in the telecommunication Industry. Packet-based networks not only
carry data but are beginning to carry voice and other traffic as well.
Intelligent Network services are evolving quickly to meet these new demands.

Intelligent Network (IN), also known as Advanced Intelligent Network (AIN),
is an evolving service-independent architecture introduced into the Public
Switched Telephone Network (PSTN) over a decade ago in the US. The essence of IN
architecture is to separate the service logic and intelligence from the
switching environment and move them onto much more powerful and flexible
general-purpose computers called Service Control Points (SCP). Such an
architecture provides many advantages not only for the telecommunication service
providers but also for their end-users. It allows service providers to create,
deploy and maintain a wide variety of services quickly and economically by using
a broad array of hardware, software and other development resources without the
limitations of a proprietary switching environment. At the same time, it gives
end-users the control over service definition and customization without
requiring telecommunication service provider intervention

Today, the number of new services supported by IN applications is rapidly
growing. For example, a caller soon will be able to click on a product ad on a
web page and automatically be connected to the product company’s closest local
branch for ordering and delivery. Other services being implemented on pilot
basis include, end-users controlling service features such as call-forwarding,
call-waiting and call-screening directly from PCs at their homes or offices.

Here’s a glimpse of the architecture, which is going to support these
overwhelming services.

Architectural Overview

The IN architecture specifies a number of key elements in the network
topology. These elements are:

• Service Switching Point (SSP):
The SSP is a telecommunication switch
that identifies and suspends calls requiring advanced service processing and
forwards them to an appropriate SCP via the Signaling Transfer Point (STP) or
a local adjunct to the SSP. The SCP/adjunct will interact with its database to
process the incoming service request and send a message back to the SSP. Upon
receipt of this message, the SSP will complete the call.
• Service Control Point (SCP): The SCP is at the heart of the IN
  services. It handles calls requiring advanced service processing. Normally,
  they are deployed in mated pairs that duplicate the same capabilities to
  ensure high availability and allow for load balancing. Each SCP may have
  several processors. These processors may access a common database of services
  and subscribers or each processor may have its own database, depending on the
  implementation. When the SCP receives a request from an SSP, it may simply
  query its database for the necessary information and then process the call.
  For instance, some customers want calls to be routed to different physical
  locations, depending on the area code of the caller. In this case the, SCP
  would simply look up which physical location should receive the call and
  inform the SCP about the destination. In other cases, the SCP may require
  further information from the user. To handle these calls, the SCP will route
  the call to an Intelligent Peripheral (IP) that can interface with the
  customer. For example, with credit card calls, the SCP would route the call to
  an IP that could accept Touch-Tone input. Once the IP had received the
  customer ’s credit card number, the SCP would verify its validity and
  complete the call.
• Adjunct: They perform the same function as the SCP, except that is it
  used for one or a few services on a single switch. Typically this arrangement
  is for supporting very fast response time, since the connection between an SSP
  and an adjunct is local at high speed without the overhead of going through
  the STP.
• Signaling Transfer Point (STP): They are intelligent routers that
  route messages between SSPs and appropriate SCPs.
• Intelligent Peripheral (IP): The intelligent peripheral is a device
  that can connect to an IN call to provide services like tone generation, voice
  recognition, playback, compression, call control, record and dual-tone
  multi-frequency (DTMF) detection and collection. Examples of IPs are those
  that process Touch-Tone and voice.
• Service Management System (SMS): The SMS is responsible for
  configuring SCPs, provisioning new services and updating SCP databases. The
  SMS is also responsible for managing the operation of SCPs. It is used to
  manage the master database that controls IN customer services. Each SMS can
  manage several different SCPs offering different services. For example, an SMS
  may control one SCP that handles a credit card service and another SCP that
  handles a virtual private network service.
• Service Creation Environment (SCE): The SCE is a non real-time system
  for creating, testing and deploying new services. The SCE has a sophisticated
  suite of tools for creating service processing logic. The SCE has a database
  that contains common building blocks for services. By using these building
  blocks, developers can create new services in a fraction of the time it would
  take to create them from scratch. Since service providers can derive
  significant leverage from an SCE that facilitates faster service development,
  the implementation of SCE differs significantly from vendor to vendor.

In conclusion, the platform for rapid service deployment and customization
has been laid in the form Intelligent Networks. Now it is for the service
providers and the end users worldwide to exploit the potential of the
Intelligent Networks.