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Virtually every aspect of the telecom landscape is undergoing a profound transformation - from the kinds of services that consumers demand to the operators that provide them.  That transformation largely is being driven by the internet, which has changed the nature of communication.  Voice service has been relegated to a commodity; the new order of business is about being "always on," mobile and interactive.

Mobile operators worldwide are making the move to IP networks to meet the demand for multimedia services like mobile web, gaming, mobile IM, and video-on-demand. The transition from a voice-centric to a service-centric network requires not only a rethinking of the architecture but of the tools and metrics used to ensure its performance.

While end-to-end IP networks seem inevitable, operators are taking a variety of paths to get there.  Some are deploying next-generation networks (NGNs) like VoIP. Others are using NGN as an intermediate step to IMS.  And, a few bold operators are jumping right into IMS technology.  Whatever the route, the reality is that that hybrid networks - a combination of circuit-switched, NGN and pre-IMS, session initiation protocol (SIP)-based technologies - will coexist well into the foreseeable future.  Operators will have to interwork a multitude of technologies, protocols and network resources for many years to come to ensure seamless service delivery.

New players like Google (You Tube), eBay (Skype) and social networking sites like Facebook and Twitter are moving in to claim a stake in the lucrative, converged multi-service market. Telecom operators must expand their business model to include new partners such as content providers, advertisers and MVNOs. This new value chain presents new arbitration and SLA requirements.

IP enables a new universe of media-rich applications that expands the realm of communication from simple person-to-person to person-to-content and group services.  Creating a multimedia experience is a complex task that requires the orchestration of applications, a staggering array of access devices, multiple technologies and network resources. Adding presence- and location-based capabilities to those applications further compounds the operator's challenge.

Beyond basic monitoring
Building a next-gen network is just part of the equation.  Equally important is operational excellence -- a key differentiator in this service/subscriber-focused business model. New protocols, new network elements and the complexity and variety of services can all have a serious impact on service quality. This converged environment requires a fundamental shift in focus - from basic network monitoring and troubleshooting to overseeing end-to-end network connectivity and service interaction to ensure a positive customer experience.

The complexity of network management increases dramatically as operators move from the delivery of predictable, low-bandwidth voice services to advanced, high-bandwidth data applications. Operating hybrid networks requires the interworking of numerous technologies and overseeing interconnections between multiple domains and partners. More network elements are required to blend real-time services such as voice and video with non real-time applications like presence, availability and user preferences. Operators have to manage the health of the end-to-end network and all of its associated resources. Niche monitoring systems do not have the flexibility and scalability to provide a complete view of the network with the data, reports and alarms required to proactively manage multi-technology, multi-protocol networks.

QoS is more problematic in IP networks than in the circuit-switched world. Yet, in today's highly competitive environment, it often is the single most critical factor that separates one operator from another in the subscriber's mind.

In legacy networks, connection points, from which usage data are derived, are well defined. In the packet world, determining which subscribers are using the network and what services they are accessing is a more complicated task. Add to that the fact that the IP domain has so many components. On which network elements should the operator focus to gather mission-critical usage data‾

Operators have had decades to perfect their diagnostic systems in legacy networks. But, service quality in IP network can be elusive. Numerous factors can degrade a session's connection quality - latency, packet loss or jitter. QoE has to be a high priority when delivering multimedia applications. For services like video conferencing to be successful, they must mimic real life. Audio and video have to be synchronized to create an experience that closely resembles a face-to-face conversation.

Operators need to correlate what the consumer expects to see and hear with what they actually experience. The MOS provides a numerical measure of the perceived quality of the transmitted media. QoE is most critical for video applications, which are particularly sensitive to impairments. Packet delay or loss can produce a range of degradations in the service (and customer) experience. It is not just a matter of determining what bits are lost; where those bits reside in the video frame sequence is also important. Even a low packet loss can produce severe degradation if the reference or "I-frame" is impacted as that degradation is propagated to subsequent frames.

Deep packet inspection (DPI) has emerged as a valuable technology to aid operators in creating application-aware networks. With DPI operators can look inside the packet payload to identify individual streams of traffic on a per-user and per-application basis. Armed with this granular level of information, mobile operators can carry out marketing, engineering and operations functions in a much more sophisticated fashion than was possible by simply analyzing the packet header. 
As the networks converge, a single session can traverse multiple networks, including TDM, VoIP, IMS, 2G/2.5G/3G and cable. Therefore, the ability to perform a real-time call or session trace network-wide across multiple interfaces and protocols is critical. With this capability operators can tie together messages for each session and track the session across the network to determine where irregularities and failures occur.

Access to real-time data is essential to tracking service availability, reliability and delivery and to understanding the quality of service and customer experience. Equipped with real-time data, operators can identify the source of service disruptions before customer complaints arise and revenue is lost. They can trace transactions, verify service delivery and identify the source of failed transactions. Real-time subscriber statistics, including send/receive time, throughput, abort and transmission rates, enable operators to understand service efficiency and the customer experience. Service usage data also permits providers to identify the most popular services, enabling them to create new, targeted marketing programs.

Whether in NGN, 4G/WiMAX or future IMS networks, visibility into the user experience and service interaction is critical to network performance and service assurance. Operators will require new KPIs that analyze not only signaling messages but also the quality of the voice and data payload. As operators move to service- and subscriber-focused networks, they will need new metrics that measure network availability and accessibility, as well as service accessibility, integrity and retainability.

Kim Bagaasen is senior product marketing manager at Tekelec.