January 2004

OSS For Next-Generation Networks

BY DEEPAK SWAMY & MICHAEL KHALILIAN

New network management challenges face service providers as they increasingly deploy voice and multimedia services on packet networks. Next-generation packet network-based telephony services (NGN telephony services) call for next-generation operations support systems (NGOSS) that are able to manage delivery of the entire portfolio of services from end to end. These systems must be able to support the flexible modeling and definition of NGN telephony services. This is particularly important with the emerging new application-based services such as Web-enabled conferencing and collaboration, integrated voice and data managed services for call centers, and personal productivity services. The new generation of services requires management systems to manage not just the underlying networks, but the end-to-end service as it is delivered in an application-specific context to the customer in a multi-vendor environment.

NGN telephony services are being deployed on a complex infrastructure that is layered on other networks (e.g., IP over MPLS or ATM) and that must seamlessly interoperate with existing TDM networks. The multi-vendor environment of next-generation architectures creates challenges in fault (correlation) and performance management. Softswitch technology is beginning to reach critical mass in major deployments. However, the challenge is to develop systems and tools that can manage the service from end-to-end and assure delivery for each individual customer according to their individual service level priorities. Finally, the service provider must be able to offer the new services at price points that are similar to TDM-based telephony services.

Taking a Functional View
Migration to packet networks creates a new set of management challenges both in managing the infrastructure and service within the service provider�s own domain and in the end-to-end service �as delivered� to the customer. These issues may be categorized within the framework of the TeleManagement Forum�s eTOM (Telecom Operations Map) which describes three key groups of OSS functions.

Service Fulfillment
Key areas to address in developing the OSS requirements for the service fulfillment function include:
� Network interconnect provisioning.
� Signaling link provisioning (e.g., SIP trunks).
� Service-to-network modeling.
� Customer order management and activation.
A key component of the new requirements will include the capability to manage the distributed nature of the NGN telephony services infrastructure. In one of the major changes from TDM provisioning, provisioning activities will need to be repeated across this distributed infrastructure (e.g., n times for n media servers, and the like).

Assurance
New and improved performance, fault, and service level management capabilities are essential for a successful transition to NGN services. These functions enable service and revenue assurance and can generate a robust ROI. By measuring and baselining key areas such as call processing, transport quality, and per-customer metrics, operations groups can ensure customer retention and satisfaction by delivering services that meet expectations. New metrics and measurement techniques -- close to the softswitch applications -- must be created and customized for VoIP and NGN services. Further, service providers must be able to quantify the service and business impact of performance issues and faults in a repeatable manner with �learning systems� that compute such impacts instead of using the �codebook� approach.

Integrating performance and fault data together with near-real time traffic data analysis enables service providers to manage the service from end to end, and from top to bottom. This will be particularly important as NGN telephony services require such extensive interoperation across service provider and customer domains.

Billing
For NGN telephony services to be successful, service providers must be able to enable usage-based and session-based billing without a forklift upgrade of the existing billing systems. This will likely require a keen focus on mediation and rating systems.

The 1996 Telecommunications Act stipulates inter-LEC interconnection, and there are established mechanisms for carrier-to-carrier compensation. Inter-carrier reciprocal compensation requires the generation of properly formatted call data records that enable each carrier to declare the percentage of local usage and measure the amount of traffic being exchanged in terms of minutes of use.
Several organizations are proposing alternative approaches to inter-carrier settlements, and this remains one of the most important issues surrounding billing for NGN telephony. Particularly when one considers varying codec use, and the support for multiple classes of service, it becomes imperative that service providers are able to transparently exchange usage- or session-based rating information and capture such information for revenue reconciliation purposes.

Taking a Process-Oriented View
NGN Service Management requires changes and new approaches in many areas:
� Business Management Layer (BML) -- Management of dial plans, billing data management, etc.
� Service Management Layer (SML) -- Modeling and management of end to end service, customer configuration, voice features and catalog, performance and service quality assurance, inventory, CALEA compliance, etc.
� Network Management Layer (NML) -- Management of faults, configuration and subscriber end-points, SS7, PRI, etc. Also management of the control technologies including H.323, SIP and MGCP.
� Element Management Layer (EML) -- Management of multi-vendor gateways, softswitches, IP phones, call managers, NAT and firewall issues.

NGOSS Advantages
By implementing next-generation operations support systems in a synchronized manner with infrastructure evolution and replacement from TDM to packet networks, service providers can ensure their ability to flexibly model services from end to end, mapping the service to its underlying domains and networks. Using NGOSS, service providers will be able to realize a new paradigm of management consolidation -- the ability to manage and aggregate customer, service, and network-level data by NOC, by region, by legal or virtual entity. This capability will grow increasingly important to service providers� ability to pro-actively manage their services and revenue streams as NGN telephony services erase many traditional provider and enterprise boundaries, and services traverse both packet and TDM networks -- a scenario that is likely to persist for many years to come.

Deepak Swamy is senior vice president and chief strategy officer at Trendium, Inc., an International Packet Communications Consortium (IPCC) member company and a developer of service intelligence OSS software based in Fort Lauderdale, Florida.

Michael Khalilian is chairman and president of the International Packet Communications Consortium (IPCC), an industry consortium of carriers and solutions providers advancing packet-based communication technologies. For more information, please visit www.packetcomm.org.

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