magazine - Connect-World

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