Oct 6, 2009

Next Generation Networks Control Plane Challenges

The Challenge
The introduction of NGN elements into the telecom network present opportunities to utilize technological advancements to reliably and cost effectively provide a broad array of all IP based services (mobile data, streaming video, advertisements, stock-market quotes,…) to an ever-expanding customer-base, in real time. Yes, we all know NGN is not happening overnight, nor is it happening all over the network at one time. But it is clear to the telecom observer that certain NGN elements are making their appearance in the telecom network, at times as a new Diameter-based OCS node and at other times as a newly introduced NGN element such as a PCRF.

But to make this efficient, manageable and cost effective, the telco must adopt an overall NGN strategy. This NGN strategy needs to take into account both the opportunities that NGN presents to them as well as deal with the challenges presented by the new architecture. An NGN strategic view is especially important because an NGN network doesn't happen overnight. The last thing a telecom operator would like is to have an evolving NGN introduction without a real vision of the final goal. Were NGN an easy short term effort, the coherent implementation would be a simple part of the NGN project implementation; but NGN introduction is slow, at times very local to a specific area within the network (such as the interface between the GGSN and the OCS). Especially under these conditions the challenge of having an overall NGN strategy is crucial to the telecom operator.

Of the many opportunities and challenges that NGN strategy presents to the telco, I would like to focus on those related to the NGN Control Plane. Unlike legacy networks, in which the control plane was primarily the proprietary domain of the Network Equipment Provider, the new NGN control plane is more open and standard. It benefits from well defined interfaces and functionalities and a new broad and flexible enhanced AAA signaling protocol –Diameter - which replaces the existing variety of legacy signaling protocols.

Information that in the past was very difficult to retrieve from the network is now easily obtained. Interfaces requiring long and cumbersome integration are now replaced by standardized connectivity. NGN signaling enables new, fast, easy and cost effective service launches, translating into more services to the customer.

However, this new NGN architecture faces some critical challenges (especially since more and more services will be, over time, launched based on this architecture):
· How to roll out and activate new real time services.
· How to handle the rapidly increasing signaling volume from the new services (which are typically more signaling-intensive than common in the past. Most legacy protocols that are UDP based, Diameter is TCP-based, with an ACK for each transaction – this alone doubles the amount of signaling),
· How to deal with the unavoidably greater fragmentation and amount of network components needed for real time and new multimedia services introduced by NGN.
Thus, load balancing (LB) becomes a key issue, - specifically the control plane load balancing.

This is the challenge of the Control Plane – ensuring that the network is able to optimize the signaling load according to individual telco-defined network, subscriber needs and business operations parameters.