A network evolution needs a security revolution

Guest post written by Ilia Abramov, Product Director @ Xura

Ilia Abramov, Product Director, Xura

Signaling networks, enabling the exchange of information that sets up, controls and terminates calls, have been through multiple stages of evolution since the early days of telephony.

Signaling System No. 7, or SS7, was developed to exchange information over digital signaling networks specific to mobile operators, and requires specialised equipment to fulfil even simple connectivity.

The complexity of its protocols, and the fact that it is used only by a closed circle of mobile operators, means that SS7 offers very controlled access to the networks themselves. That said, it’s worth bearing in mind that an SS7 network contains crucial information regarding a mobile network such as subscriber data, and mobility and authorisation information.

SS7 networks have since evolved to become IP-based, making them more accessible to a wider community outside of traditional mobile operators. But, with the emergence of cheaper, and better performing IP solutions, the level of trust has dropped significantly.

Diameter–SS7 IWF: Bridging the Signals between New and Old Worlds

Ohad Ramot, Principal Software Engineer, F5

F5’s Ohad Ramot explains the challenges of translating signals between a 4G network using Diameter signaling and 3G networks using legacy SS7.

It’s widely known that LTE (4G) networks are spreading rapidly and are being deployed all over the globe. However, while 4G networks are growing, 2G/3G networks still serve most of the subscribers as they have been doing successfully for the last decades, and it seems these legacy networks are here to stay for a while. This requires operators and roaming mediators (IPX) to face the challenge of maintaining and interacting with both network architectures in parallel.

4G and 2G/3G network architectures differ in many aspects. One of the major differences is the signals mechanism that enables network nodes to interact with each other for authentication, billing, subscriber profile provisioning and more. While 2G/3G signaling mechanism is based on SS7 protocol stack, 4G networks use the relatively modern Diameter protocol on top of TCP/SCTP/IP stacks. Although both signaling methods provide solution to the same set of problems, they stem from different architectures and design philosophies.

Diameter Signaling: Change Determines Survival

This post is by MK Chang, vice president, product marketing for Aicent.

The promise of 4G LTE and its native IP packet based technology is quickly proving its value on the world telecom stage. The number of LTE network installations on a global level helps support this claim with over 400 operators in over 124 countries investing in LTE according to GSA and up to 175 networks already commercial. This is also apparent in the rising number of greenfield opportunities for data service providers helping drive growth with new services through innovative business models.

All these influence the momentum behind the explosive interest and growth of LTE networks, which in turns gives rise to the evolution of Diameter signaling and may eventually take over the critical importance of SS7 in the signaling world.

With the exponential growth of data, the mobile industry has been guardedly awaiting the impending data surge that is building from the increased adoption and expansion of data devices. The result, is the expectation for the Diameter signaling market to double this year (2013), with revenue from signaling controllers jumping to well over 900% from 2012 to 2011, according to Infonetics.

This push into Diameter signaling comes at a cost, and that cost is to the more outmoded and aging SS7 network, lessening its importance and creating a tremendous amount of turbulence in the traditional telecom wholesale world – where change determines survival.

So what are the impending factors that will impact SS7 and continue to drive the development and expansion of Diameter Signaling?

• Improved Scalability and Management

Newer technologies, such as Diameter, are able to handle higher volumes (data) with the same or smaller physical footprint. The Diameter infrastructure simplifies network management through a singular centralised signaling architecture reducing costs (Opex) and the complexity of the core network, while allowing the network to grow incrementally to support an expanding base of data hungry mobile subscribers.

• Long-Term Consumption

As subscriber adoption and penetration eventually levels off and starts to decline as a result of the rapid shift by global operators to LTE networks, 3G traffic will become relatively flat. This will have direct implications on operator demand for SS7 signaling services, which will gradually decelerate, equating to a decreased demand for SS7 supporting equipment.

• VoLTE

Over the coming years, improved services, reduced capital, and operating expenses will drive operators to minimise their support for SS7 signaling at the core, as it is replaced with new and advanced services such as VoLTE, that benefit from Diameter’s ability to handle an all-IP network landscape. This transition will only quicken as IP to IP calling becomes more mainstream.

• Competitive Landscape

The increasingly competitive telecom services market, drives carriers to focus more attention on subscriber retention by raising customer service levels and injecting new and updated services in order to build strong customer satisfaction, support, and retention (lowering churn), all while reducing costs. The injection of new services is an opportunity to offer differentiated services that increase customer spending, while improving customer satisfaction.

• Role Of The Wholesaler

LTE roaming is predicated on the existence of an IPX. As Diameter signaling volume grows, operators may be increasingly encouraged to use the IPX as a direct bilateral method for services like inter-carrier voice as well as SS7 signaling. This might translate into a diminished role for the international carrier acting as a wholesale agent between carriers. Certainly, the overall signaling and voice market will be big enough to sustain both IPX and wholesale players, yet there is no doubt of the increasing pressure on these international wholesalers to change in order to survive. Consolidation of the wholesale international market may be an eventuality.

There is no question, the SS7 network infrastructure will continue to exist in the near term for several reasons. One being the investment costs associated with equipment and the other is supporting a legacy mobile market that despite quickly redirecting its attention to LTE (probably the fastest adoption of a new technology in mobile’s short history) will still need to support existing users while the industry transitions over the next 5 to 10 years. This is also the case for operators within countries that are just at the cusp of transitioning from 2G to 3G services and will maintain this model for some time. The future trend will continue to focus on 4G LTE networks supporting the dynamic growth of data centric devices.

To talk further with Aicent, head down to Pod 10 on the exhibition floor of the LTE World Summit, taking place on the 24^th-26^th June 2013, at the Amsterdam RAI, Netherlands. Click here to download a brochure for the event.

Aicent are also nominees for the Best LTE Roaming Product or Service at the LTE Awards 2013, taking place at the 25 June 2013, De Duif, Amsterdam, Netherlands.