The Transition Agents

VoicenData Bureau
New Update

As technologies for carrying voice and data mature and converge, service

providers and enterprises are increasingly viewing voice over packet (VoP) based

network as a way to reduce communications costs, boost end-user productivity and

enable new applications. Such network architectures not only handle multiple

kinds of traffic in a cost-effective way but also competitive services, which

integrate voice, data and multimedia, which are going to be the key



Operators’ Strategy

When considering the deployment of NGNs, strategy of a telecom operator is

going to depend upon its history (incumbent vs green field), market situation

(deregulated vs monopolistic, strength of competitors), status of its networks

(single equipment provider vs several, recent or less recent products), and the

evolution of its customers’ needs (traffic, services, etc).

For the operator, some of the key reasons in favor of NGNs are to:


Niraj K Gupta


operators want to protect the large investments made in the access

nodes. Hybrid platforms that exhibit features of TDM and allow

evolution to softswitch are the answer

l reduce time to

market for new technologies and services

l facilitate vendor,
carrier, or third-party development of software

l reduce operational
complexity by standardized modular systems

l separate call
processing from switching/transport function through open interfaces

The associated objectives underlying this approach would include:


l support ATM and

IP connections in addition to legacy TDM connections

l keep the present
level of voice features when evolving from TDM-based networks to VoP solution

l support voice,
video and data services

To address these needs, the vendors are developing NGN solutions (including

call servers/softswitches, trunking and access gateways, IP/ATM networks nodes,

etc) to cope with the actual requirements of different operators, and are

offering traditional voice services as well as advanced new multimedia services.

The new operators may directly install softswitches and gateways (trunking or

access gateways) to handle the Class 4 or Class 5 applications. However, Class 5

application on softswitches will take some time to develop. So they look for

platforms, which can provide Class 5 applications on TDM at present, but which

can migrate to NGN smoothly.


Large installed base of TDM-based traditional networks, make the incumbent

operators look for a smooth transition to the full NGN architecture, to protect

the large investments already made in the access nodes. Hence, they look for

hybrid-platforms, which can give all the features of TDM and evolve to a

softswitch–integrated inside the TDM switch itself–ensuring migration of

subscribers from the TDM environment to the NGN environment, without any


Platforms being designed for these large incumbent operators address the

following requirements:

n investment

protection by reuse of the installed switches as well as external devices, such

as IN service control points, network management centers or customer-care and

billing systems

n networks’ smooth
evolution without service disruption

n functional
continuity of features and services


NGN Network Strategy

Existing networks, catering to separate voice and data transports, can be

optimized by the introduction of new high-capacity switches to drastically

reduce the number of switches and thus, the OPEX costs.

At access level, voice and data convergence is already happening through mass

deployment of ADSL on copper lines. At the transit level, NGN is implemented

initially via VoP transport with stand-alone call servers (Class 4 or transit

call servers), controlling trunking gateways in charge of the PSTN-to-packet


Introduction of the media gateway controller (MGC) feature in TDM switch,

enables the operators to move smoothly to NGN with full continuity of services

at the desired deployment pace. MGC allows control of additional gateways, which

interconnect existing access unit/trunk to packet network.

This solution allows a progressive hand-over of voice traffic from the TDM

world to the data world, while retaining the existing end-user services as well

as the control and management interfaces. This would ensure networks’ smooth

evolution without service disruption, besides investment protection. n