Next Generation Networks: Empowered Servers

VoicenData Bureau
New Update

One is volume. The other is value. One tremendously determines the top-line.

The other greatly influences the bottom-line. Voice and data, they do co-exist

in different ways in the networks of different carriers. The present, itself is

confusing. The future, as envisioned, a heady mixture of success, uncertainty

and risk.


The decision-making for the operators is certainly tough. Do they go in for

complete fork lifts to implement an all-new IP network that has been optimized

for data services? Or do they stay on course and add more tandem trunks to their

switches, so that they can handle the surge of increasing level of data?

The consensus, after a lot of debate, seems to be the traditional Indian

belief–the middle path. In simple terms, putting in place an efficient

migration system that seamlessly transforms a traditional TDM network to an

IP-based network.

The Evolution of Packet


telephony has evolved quite rapidly since the time it was introduced in 1995.

During its adoption phase, it emerged merely as a hobbyist’s pastime when the

PC was used as a cheap option to make telephony calls in an unregulated market.

But today, when one tracks the evolutionary trends in packet telephony, it is

seen that on the services front, the development curve is reaching almost

vertical levels.


So the question is: where is the infrastructure that supports such services?

Surprisingly, while the scope of services that can be offered on a packet

network is skyrocketing, on the infrastructure front, technology is reaching

more mature levels and is approaching a plateau stage. This signals the fact

that carriers no longer need to rely on complete fork lifts to provision

IP-based services in their networks. Thanks to the efforts made by some vendors,

who have assessed the volatility of the situation and have come up with

technologies and solutions that help carriers seamlessly transform traditional

TDM networks into the packet domain.

Market Drivers

Before entering into the era of ‘Next Generation Networks’ (NGNs) let us

have a look at the prime market drivers.

n Surge in

bandwidth demand:
One of the prime drivers is the surge in the demand for

bandwidth by the end users, as they consume more and more bandwidth and demand a

growing portfolio of data and voice services. This has led many service

providers to manage more than 6—7 separate networks deploying special multiple

purpose networks. But then the overheads in managing these networks also

increase in such a scenario. This has led some of the more aggressive players to

look at options of deploying multi-service networks that they claim will save up

to 70 percent in terms of cost.


n Deregulation:

Deregulation has been taking place in most of the regions and this in turn is

increasing competition. And increase in competition means putting pressure on

the service margins of operators. It is because the only differentiation that

service providers can make at this point is the price. Therefore, it is

imperative that service providers deploy newer services much faster than the

competitors. Therefore, the NGN must offer integrated network management to make

it easy for operators to run the networks efficiently and sensibly, and deliver

premium levels of service and responsiveness with minimum operational costs.

n Importance

of QoS:
Service providers are signing SLAs that require high quality-of-service

(QoS). It is because many multimedia applications require quite stringent QoS in

the network elements. Therefore, NGNs must preferably offer end-to-end QoS

control via one distributed management system. Further, insights into the market

reveals that there is no such thing as a homogeneous serving area. It is because

of the varied demand pattern of customers, so it is important to be able to

satisfy them, without increasing network complexity. Thus, the NGN must be able

to support multi-protocol service architecture, so that it would be possible to

provision different levels of service in one managed network.

n TDM networks

not optimized for data:
Another major factor, which is a market driver for NGNs

is that the traditional TDM networks are not optimized to carry data. But the

surge of data has forced operators to add more telephony trunks to match the

onslaught of data traffic. But this is a costly and inefficient way to carry

data. While TDM switches have been inherently profitable for operators to carry

voice and huge investments have been made to build these networks, calls for the

operators to choose a smooth transition path to the multi-service ‘Next

Generation Network’. The scenario is especially true for incumbent’s network

where there are numerous small switches in the network. Given such an

environment, they involve a huge operational cost to operate and provision these

trunk groups. The other issue with TDM networks is that new service introduction

usually requires service upgrades to be made in all the switches.


Best of Both Worlds

The more prosperous service providers in the future will be the ones who are

able to retain the best of their existing networks while transforming them with

the best of the new networks. With judicious and well-timed investments, service

providers can convert their existing voice-optimized networks into a completely

multi-vendor compatible, multi-service network, optimized to carry IP and

end-to-end services over a variety of architectures. The network transition

process is critical, as they still have to carry on with the existing services.

In the existing TDM-based networks, significant savings can be achieved by

consolidating several layers, as this could translate into capex and opex


Consider asynchronous transfer mode (ATM) for instance. With the right ATM

architecture, service providers would save a big chunk of change eliminating

cross connects and network elements, while still exploiting the efficiencies of

ATM to consolidate routes with switched virtual circuits and slashing trunk

administration costs. Therefore for serving a customer base that demands various

levels of service, ATM turns out to be a clear choice.

Services: Closer to the User

A discerning look at NGNs reveals that it means provisioning services on a

‘distributed network intelligence’. Distributed network intelligence means

that the intelligence resides in the standards-based servers that reside on the

edge of the network, unlike legacy networks where the intelligence resided on

the switches.


Under a distributed intelligence architecture, we would be entering into an

‘Open Programmable Era’, and this is what a NGN is all about.

It is because the intelligence residing on the servers at the edges allow

custom development for service providers and third parties, so that they can

configure services based on their requirements. Whereas at the core, packet

telephony application is agnostic for the core connectivity, therefore it is

immaterial if the core backbone is IP- or ATM-centric. So the issue really

resides in the edge of the network. The NGN is based on a distributed rather

than on a nodal architecture.

The new network moves access and services out of the switch-based backbone to

the servers residing on the edge. In this process, network and service control

move into the hands of service providers and ultimately to the subscribers.


core to edge
The emerging paradigm is that of distributed network intelligence
Here, the intelligence resides on the standards-based servers
This is unlike legacy networks where the intelligence resided on switches
Service providers and third parties will be able to configure services based on their requirements

As the convergence of voice and data networking advance, the most successful

service providers would be those who implement a rapid cost-effective

transformation strategy that reuses the key elements of the TDM network to

provision next-generation services. While the introduction of an ATM switch can

be the first step to commissioning a NGN, a generic NGN architecture would

comprise of a multi-service delivery mechanism using multi-service gateways to

carry traffic onto a high-speed broadband ATM switching fabric or on MPLS core.

With such architecture, the definition of a ‘central office’ takes a new

dimension unlike that of the TDM networks. Conceptually speaking, it assumes the

nature of a distributed architecture consisting of multi-service gateways, ATM

switching platform or MPLS switches at the core, and finally, the server based

intelligence to pull it all together. It means that many of the functions of a

TDM central office, such as SS7 connectivity, call control and a unified view of

network management, are now provided through the ‘new central office’, the

next-generation network.

Therefore, in this transformation scenario, familiar and profitable services

can still continue uninterrupted because the integrity of the SS7 signaling,

which is essentially a TDM functionality, and the value is preserved even as

connection control is passed to the ATM or MPLS devices. In the logical

extension of this transition strategy, TDM components would be slowly phased

out, paving the way for applications and services to migrate to network servers.

And moving these components to the network servers would mean that custom

services can be developed by the service provider and will eventually move down

to the subscriber.

Finally, should we say that a rapid transformation into a packet network

should be the one that reuses the components of the TDM network, which is the

logical business course for any service provider to enter into ‘an open

programmable era’ of NGNs. Logically, it does makes business sense to preserve

the value, in terms of services and revenues of the TDM network, protecting the

huge investments made, while transitioning into a data-centric future.

Sandeep Sharma, Manager (product marketing) VoIP and intelligent Internet,

Nortel Networks