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Signaling traffic<br />
popular applications like Apple’s FaceTime<br />
over cellular or QoS-driven VoLTE and<br />
video, or tailor Mobile Ads with subscriber<br />
data, Diameter signaling will need to be<br />
addressed. If not, it will become increasingly<br />
difficult to personalize mobile data services.<br />
Operators need to apply advanced policy<br />
rules, and they will have to manage the<br />
consequent increase in Diameter messages<br />
among policy and charging systems, and<br />
subscriber databases.<br />
Why a centralized diameter approach<br />
‘Signaling storms’ have already hurt network<br />
performance and compromised the customer<br />
experience. In the shift from unlimited to<br />
usage-based data plans, for example, signaling<br />
surges were experienced by several operators.<br />
Operators that are now in the planning stages<br />
have learned from others to incorporate<br />
Diameter signaling strategies into their<br />
network architectures. The lesson: a separate,<br />
intelligent New Diameter Network is needed<br />
from the outset of LTE networks, and<br />
cannot wait until ten million or 20 million<br />
subscribers join the network. A meshed<br />
architecture-the direct connections between<br />
each network element-simply cannot scale<br />
sufficiently, even at low subscriber numbers.<br />
Scalability problems abound in the SS7<br />
world, too. But where SS7 did handle<br />
congestion, traffic overload and traffic<br />
throttling, Diameter does not!<br />
Operators assumed that IP networks would<br />
handle those responsibilities on a ‘best-effort’<br />
basis, but now it has become obvious that the<br />
Diameter protocol has to be deterministic to<br />
address issues at the IP layer.<br />
Currently, Diameter is at the end of year two<br />
of a five-year development cycle and the<br />
IETF is leading standardization to incorporate<br />
new capabilities into the protocol. In the<br />
meantime, operators should increase their<br />
focus on the signaling core.<br />
Building dynamic and resilient networks with<br />
a diameter signaling router<br />
As operators and vendors learn more about the<br />
impact of applications on the Diameter network,<br />
operators are focusing more on the signaling<br />
network and the role it plays in supporting<br />
innovative and sophisticated applications.<br />
Traffic engineers that understand how a<br />
signaling network works are looking more to<br />
Diameter Signaling Routers (DSRs) as a means<br />
to prevent further outages and optimize what<br />
they can do to enable or participate in new<br />
mobile-data business models.<br />
The DSR enables an architecture that<br />
reduces the cost and complexity of the<br />
core network, and it helps IP networks to<br />
grow incrementally in support of increasing<br />
service and traffic demands. Additionally,<br />
the DSR facilitates network monitoring by<br />
providing a centralized vantage point in the<br />
signaling network.<br />
When evaluating solutions, operators should<br />
consider how robust and proven a solution is<br />
in 3G mobile data and LTE networks, as well<br />
as its roadmap for the future.<br />
Important for a solution today is the ability to<br />
handle hundreds of thousands of messages;<br />
tens of millions of concurrent sessions;<br />
and millions of subscribers and devices.<br />
Also important are extensive scalability<br />
and congestion control features. But for the<br />
future, there has to be a path to virtualization,<br />
as operators are going to want to move the<br />
DSR and related elements like policy and<br />
subscriber data management into the cloud.<br />
As more architectural agility becomes<br />
necessary to handle signaling and data traffic<br />
surges, the DSR’s operations, administration<br />
and maintenance (OAM) functions will have<br />
to be virtualized.<br />
Already, operators in the Asia-Pacific<br />
region and IP Exchange (IPX) providers are<br />
deploying DSRs with virtualized elements.<br />
As the DSR becomes increasingly critical,<br />
it will become a key component within an<br />
independent control layer - one that should<br />
be comprised of signaling, policy and<br />
subscriber data management. Tekelec calls<br />
that independent layer the ‘New Diameter<br />
Network,’ a Diameter signaling layer in the<br />
network core that handles routing, traffic<br />
management, load balancing and protocol<br />
interworking. In that context, the DSR<br />
integrates with the Policy Server (PCRF) in<br />
order to define business rules for new service<br />
plans. It also integrates with subscriber data<br />
management (SDM) to personalize services<br />
and evolve them according to consumer<br />
circumstances and preferences.<br />
As a part of the NDN, the DSR, Policy Server<br />
and SDM manage the constant pinging among<br />
essential LTE network elements, including:<br />
Offline Charging<br />
Policy Servers (PCRF)<br />
Online Charging (OCS)<br />
User Data Repositories<br />
Mobility Management Entities (MMEs)<br />
Policy Control Enforcement Points (PCEFs)<br />
Session Management, like a Call Session<br />
Control Function (CSCF)<br />
In essence, the DSR becomes the network’s<br />
central nervous system, monitoring all<br />
Diameter traffic and making decisions<br />
regarding load balancing and congestion<br />
control based on its knowledge of the entire<br />
network, as opposed to a specific segment of<br />
the network.<br />
These capabilities lay the ground work for<br />
software-defined ThinkingNetworks -<br />
networks capable of self-organizing, selfoptimizing,<br />
and self-determining responses<br />
to unprecedented and unpredictable events.<br />
In essence, networks that have to think for<br />
themselves, yet remain malleable enough<br />
that network architects can adjust network<br />
resources as needed.<br />
While operational efficiencies and cost<br />
savings are some of the benefits of<br />
ThinkingNetworks, it will ultimately be<br />
innovation and personalization that are the<br />
crowning benefits.<br />
To get to that point, there are four phases to undergo:<br />
Phase 1, the creation of the New Diameter<br />
Network - a centralized, intelligent Diameter<br />
control layer governing all equipment that<br />
uses the Diameter protocol.<br />
Phase 2 comes when the NDN moves to<br />
the cloud, creating a fundamental shift<br />
in the way operators improve network<br />
scalability and flexibility in terms of sessions,<br />
transactions, and throughput. Tekelec<br />
calls this phase Cloud XG, as the nextgeneration<br />
of cloud will depend on network<br />
function virtualization and software-defined<br />
networks (SDNs). Here, operators will look<br />
to dynamically add and remove compute<br />
resources to available hardware, and to<br />
dynamically manipulate traffic flows entering<br />
or leaving the cloud.<br />
Phase 3 is MobileSocial, where subscribers<br />
are intimately known by their providers<br />
as individuals and as members of greater<br />
social circles - personal and professional.<br />
This is where the rubber meets the road, as<br />
operators become digital-lifestyle providers,<br />
customizing customer experience according<br />
to real-time data coming from networks and<br />
Big-Data sources.<br />
As operators unleash the valuable contextual<br />
data they hold, they build opt-in, mobile<br />
advertising, and other personalized offers to<br />
OTT application and content providers.<br />
Phase 4 culminates with ThinkingNetworks,<br />
which embody all critical components of<br />
the previous phases. Founded on policydirected<br />
SDN control and network event<br />
listeners (such as event records, analytics,<br />
alarms and probes), ThinkingNetworks<br />
give an analytical view of the relationship<br />
between all of the services supported - the<br />
characteristics of each as well as the impact<br />
of one service on another.<br />
The end goal is to significantly reduce<br />
network costs by giving service providers the<br />
ability to dynamically assign compute and<br />
storage resources where and when needed in<br />
the network, as well as to enhance service,<br />
application, device- and user-awareness in<br />
order to further personalize services.<br />
The ThinkingNetworks vision provides<br />
a roadmap to turning those goals into<br />
reality with carefully planned steps that<br />
get operators from where they are today to<br />
where they want to be tomorrow as Digital<br />
Lifestyle Providers. •<br />
30 • EMEA 2013