WHITE paper

www.hcltech.com

modernizingthe OSS approach

for VirtualInfrastructure

Introduction

Traditional OSS approach

Need for OSS evolution to support Hybrid Networks

Service Fulfillment - Agile design and creation of new services

Service Assurance - Real time operation

Fault Management

Performance Management

Inventory Management

OSS Integration architecture for Hybrid Networks

Use Case 1 – Fulfillment – Service Fulfillment Agility

Use Case 2 – Fulfillment - Up-to-date Inventory

Use Case 3 – Assurance – Real time Fault Management

Use Case 4 – Assurance - Real time Performance Management

Benefits of this approach

3

4

5

5

6

6

7

7

8

8

9

9

10

10

Table of Contents

Traditional OSS systems handling legacy networks do not follow a standardized approach in the management of physical NEs. These OSS solutions work in silos, each focusing on specific functions (e.g. inventory, performance assurance and monitoring, trouble ticketing, service configuration and activation, fulfillment, test and diagnostics, etc.). These systems do not have the capability to abstract the end-to-end network and map service to underlying network resources. Inventory information is not centralized and is maintained in different forms in different locations. All these contribute to lack of agility and automation in service delivery.

Next Generation OSS (NGOSS) is the TeleManagement Forum (TM Forum) business solution framework for creating next generation OSS software and systems. It delivers a framework and a repository of models and guidelines to facilitate rapid development of flexible OSS solutions to meet the business needs of telecommunication environment. With the adoption of Software Defined and NFV based service function deployments, the needs for flexibility in the OSS systems have increased further.

Traditional OSS Systems have been existing in the market for many years – hence it involves a lot of investment and effort for OSS vendors to align with the NGOSS standards. This in turn implies that service providers will not be ready for leveraging the SDN/NFV benefits in the near future.

An alternate solution for addressing the gaps is an architecture that deploys a “mediation layer” in hybrid networks that is capable of interacting with different NEs and the OSS. This approach does not involve major re-design of OSS solutions. However, this integration architecture needs to address several challenges from the OSS perspective, in order to be able to offer complete benefits for service providers and end customers.

Traditional Operational Support Systems (OSS) are a set of programs that help a communications service provider (CSP) monitor, control, analyze, and manage a network. OSS solutions are composed of disparate functional units for managing different parts of the network.

With the advent of Network Function Virtualization (NFV) and Software Defined Networking (SDN), the complexity of management and operations, and associated Operational Expenditure (OPEX) of virtual networks is reduced. In a practical scenario, a network will be comprised of physical and virtual Network Elements (NEs), a.k.a “Hybrid Networks”. While complete migration to virtual infrastructure is a long term goal, service providers are looking for service monetization through agility and automation in end-to-end service fulfillment, improved resource utilization (which reduces operational costs), and improved customer experience in hybrid networks. This introduces new operational scenarios for OSS and implies changes to the current network operations models and OSS solutions, to align with the benefits offered by these new technologies.

This white paper will cover the gaps in traditional OSS systems and existing challenges that need to be overcome for achieving the goals of the service provider. This paper proposes an integrated architecture for addressing these issues, which can be considerered as a modernized approach for achieving end-to-end agility and programmability of hybrid networks.

Introduction

Traditional OSS approach

Need for OSS evolution to supportHybrid Networks

The OSS Integration architecture involves a Higher Order Orchestrator (HOO) which acts as “OSS Mediation Layer” that interfaces with OSS, legacy, and virtual networks.

One of the important precepts of NFV and SDN is the ability to rapidly create new services. Service fulfilment is critical while services and the fulfilment environments have become more complex. End-to-end fulfillment involves automation, right from customer order to activation across multiple service stacks.

For rapidly creating new services, the OSS should map the services to physical resources and automate provisioning of physical NEs. From the NFV perspectiveOSS should facilitate rapid on-boarding of new VNFs / Service Functions and associated catalogues. In SDN enabled environment, OSS needs to orchestrate SDN controllers as well. Thus, OSS should enable end-to-end provisioning of services despite disparity and complexities of hybrid network.

Traditional OSS systems are not real-time, i.e. they do not adapt to a constantly changing networkenvironment in response to planned and unplanned network events.

Fault ManagementTo support the dynamic, ever changing NFV environment, OSS must work in near-real time and be able to recognise the changes to the network configuration as and when they happen. It must also provide visibility of faults across all domains and vendors, to ensure a holistic view to support assurance of dynamically changing services. With this availability of real time data, it should be possible for service providers to quickly identify and fix the source of service disruptions in several disparate and dynamic networks, before customer complaints are raised.

Performance ManagementOSS needs to display real-time statistics and performance of service related data traversing the entire network. Based on this data, it should provide the ability for service providers to analyze and characterize service function usage to plan effectively, handle growth, support service level agreements (SLAs), and avoid unnecessary capital expenditures. Real-time statistics for each subscriber are critical to understand-ing service efficiency and improving service quality. The OSS should display real time metrics to evaluate and improve service quality and proactively avoid network performance deterioration. Based on Key Quality Index (KQI), service providers should be able to isolate and locate root causes that influence service quality.

Inventory ManagementFor agility in service fulfillment and real time fault and performance management, it is critical for OSS to maintain up-to-date inventory of physical and virtual resources. The virtual environment is dynamic, i.e. Virtual Network Functions (VNFs) are instantiated, scaled out, scaled in, and terminated frequently. The OSS needs to maintain up-to-date inventory regarding virtual resources in this dynamic environment, while also maintaining accurate and centralized inventory regarding physical NEs.

Service Fulfillment - Agile design and creationof new services

Service Assurance - Real time operation

OSS Integration architecture forHybrid Networks

North Bound towards OSS:The HOO interfaces with:Performance Management system to ensure real time update of performance and quality metrics in different parts of the network. Fault Management system to propagate service faults in real time. Service Provisioning module to push service requests to Service Functions and NEs. Inventory and Topology Management System to update the changes to resources on a real time basis, to maintain up-to-date inventory.

ELEMENT MANAGEMENT SYSTEM (EMS) / NETWORK MANAGEMENT SYSTEM (NMS) for interfacing with physical network elements.

NFV Orchestrator (NFV O) / VNF Manager (VNF M) which further interworks with VNFs. NFV O interworks with Virtual Infrastructure Manager (VIM) and VNF Managers. The HOO interacts NFV O / VNF M for onboarding, instantiating, and orchestrating VNFs upon requests from the OSS.

Hybrid Network Orchestrator/SDN Controller for SDN enabled NEs.The HOO will need to handle the definition and design of ‘Service Models’ and possess the capability to map the service model to resource model and identify the NEs for realizing the service. It will rely on an up-to-date Inventory Management module for verifying the resource availability. The design and definition of Service Models is the key capability for achieving end-to-end automation in service provisioning. Apart from the initial definition of service, the HOO will also need to handle dynamic changes to service configuration.

The diagram depicts various OSS modules interfacing with HOO. The HOO plays the key role of bridging disparity between different networks, and translating the requests between OSS and different Service Functions and NEs. The HOO will need to interoperate with the following entities:

OSSModules

Use Case 2 – Fulfillment - Up-to-date Inventory:Virtual Network Functions are instantiated, scaled out, scaled in, and terminated dynamically. NFV Orchestrator needs to maintain up-to-date inventory information in this dynamic environment while the OSS needs to maintain up-to-date inventory regarding physical NEs.

This is further illustrated the following use cases:Use Case 1 – Fulfillment – Service Fulfillment Agility:For agility in service fulfillment, the NFV Orchestrator should facilitate ease of provisioning and onboarding of VNFs. This requires the OSS to automate the provisioning of physical NEs; HOO requires interoperat-ing with OSS’s existing provisioning system to facilitate end-to-end automation.

Figure 2 illustrates how end to end Service Provisioning can potentially be handled in the integrated architecture.

The operator configures a service through the OSS Service Provisioning user interface. The Service Provisioning module pushes this information to HOO.HOO identifies NEs for realizing this service and looks up inventory to segregate requests to physical NEs and VNFs. HOO propagates A. VNF related requests to NFV Orchestrator B. Physical NE related requests to EMS/NMS C. Network Interface specific provisioning requests to Hybrid Network ControllerNFV Orchestrator on boards the VNFs and updates its centralized catalogue. It allows the provisioning of VNF descriptors and performance parameters in a standardized formatNFV Orchestrator requests the Virtual Infrastructure Manager to allocate resources for the new VNF. It requests VNF Manager to instantiate a new VNFEMS/NMS configures the physical NEThe Hybrid Network Orchestrator pushes network interface specific provisioning requests further into NEs.

Use Case 3 – Assurance – Real time Fault ManagementAlarms are reported in various layers of NFV – the NFV Orchestrator requires to perform alarm correlation and propagate this information to OSS. The Higher Order Orchestrator needs to subscribe for alarms from physical NEs and collect alarms on a real time basis. HOO needs to correlate alarms reported from physical and Virtual NEs / Service Functions.

Figure 3 illustrates how the inventory can potentially be made up-to-date during dynamic Service Function/VNF instantiation and termination.

In response to a request for instantiation / scaling out or termination of a VNF, the provisioning system and HOO pushes this request to Higher Order Orchestrator and keep each other in syncHOO propagates this request to NFV Orchestrator/ VNF ManagerThe VNF Manager interacts with VIM to allocate additional physical resources for the VNFNFV Orchestrator requests the VNF Manager to create an additional VNF instanceAfter successful completion of this activity, the NFV Orchestrator informs the HOOThe HOO in turn conveys this to Inventory and Topology Manager. The inventory information in OSS is made up to date.

Diagram 4 illustrates the potential sequence of events that can be modeled when faults are reported from physical and virtual service functions, and the same needs to be correlated for dynamic service assurance requirements.Alarms are reported for faults in different layers (i.e. physical, virtual and in the VNF) of NFV - Virtual Infrastructure Manager propagates alarms related to virtual and physical layers to NFV OrchestratorVNFM propagates alarms related to VNF to NFV ONFV O performs alarm correlation for certain faults and pushes this information to Higher Order OrchestratorHOO subscribes and receives alarms from EMS/NMS and network related alarms from Hybrid Network Orchestrator on a real time basis.HOO correlates and propagates these alarms to the Fault Management Module. The OSS Fault Management Module performs correlation of alarms received from various sources to identify the root cause, and displays appropriate information to the technician for corrective action. The fault correlation at OSS helps understand how resource failures at NFV impact network services and subscribers and enables optimization and effective utilization of physical resources. This facilitates proactive analysis of faults even before a trouble ticket is raised by the subscriber, thereby avoiding service degradation.

Use Case 4 – Assurance - Real time Performance Management NFV O aggregates performance metrics from virtual NEs and reports them in real time. This requires the OSS to collect performance measurements from physical and virtual Service Functions / NEs in real time and be able to perform end-to-end correlation and predictive analysis of service consumption trends.

Figure 5 illustrates the potential sequence of events that can be modeled for real time analysis of performance and quality metrics.

The Performance Management module of OSS initiates periodic collection of performance metrics in the networkThe request is routed through the Higher Order Orchestrator which looks up the inventory and topology manager to identify the NEsHigher Order Orchestrator splits requests for NFV orchestrator, Hybrid Network Orchestrator, VNF Manager and legacy EMS/NMS, and requests for the collection of performance metrics of each system

Benefits of this approachThe operator’s services environment will adopt both physical and virtual service functions for the foresee-able future, and legacy OSS systems will require mediating layers to interwork with the evolving services infrastructure. This paper discusses some of the top use cases that get addressed by such OSS mediating layers. The following diagram explains the positioning of these use cases against TM Forum’s eTOM framework, and identifies the perceived impact areas.

Dynamic Inventory Management and End-to-end Service Provisioning facilities over the evolved Services Infrastructure establishes the Fulfilment capabilities for the Operator. While these facilities centre on Service Management and Operations, the Service Model definitions supporting the complete deployment essentially introduces the dynamic fulfilment abilities over further process areas for Supplier / Partner Management, Revenue Management Operations, and Customer Relationship Management.

Service Model definitions around Real-time Management of Faults and Performance also centre on Service Management and Operations. However, associated corrective and preventive actions introduces dynamic assurance capabilities over Supplier / Partner provided services, Revenue Management & Operations, and Customer Relationship Management process areas. In addition, the factors positively influencing Fulfilment capabilities also develops indirect influence over Operation Support & Readiness and Billing, since related Service Model definitions largely depend on the dynamic definition of services catalogue, inventory and provisioning of the dynamic service functions. Similarly, factors impacting Assurance capabilities also introduce correlated Service Model definitions indirectly influencing Operation Support & Readiness and Billing.

The NFV Orchestrator requests VNF Managers and VIMs to collect data from VNFs, Hypervisors, and physical resources. The EMS/NMS requests this information from Physical NEs. The Hybrid Network Orchestrator requests this information from Physical/virtual NEsThe VNFM/NFV Orchestrator, Hybrid Network Orchestrator, and NMS perform aggregation of performance metrics and respond to HOO. The HOO computes the service metrics and service quality index and feeds this information to OSS Performance Management moduleThe HOO feeds this information to Data Analytics module, which utilizes the current metrics along with previously collected information to perform predictive analysisThe OSS Performance Management module displays the service level metrics along with predictive analysis results in OSS GUI. This contributes to service quality improvement and enables proactive network maintenance and optimization.

References

ETSI NFV Management and Orchestration: http://www.etsi.org/deliver/etsi_gs/N-FV-MAN/001_099/001/01.01.01_60/gs_NFV-MAN001v010101p.pdf

Next Generation OSS/BSS: http://www.slideshare.net/grazio.panico/ngen-oss-bss-architecture-evolution

How to avoid NFV transformation pains: http://www.vanil-laplus.com/2015/01/20/4448-how-to-avoid-nfv-transformation-pains-part-2-tell-me-where-it-hurts/

How to drive NFV service agility and drive new service innovation: http://inform.tmforum.org/strategic-pro-grams-2/agile-business-it/2015/11/how-to-deliver-nfv-service-agility-and-drive-new-service-innovation/

Priya joined HCL in August 2014. She has extensive experience in CDMA, primarily in the areas of Security (identification of vulnerabilities and architecting security solutions), Element Management, and Network Management.

TM

Hello there! I am an Ideapreneur. I believe that sustainable business outcomes are driven by relationships nurtured through values like trust, transparency and flexibility. I respect the contract, but believe in going beyond through collaboration, applied innovation and new generation partnership models that put your interest above everything else. Right now 110,000 Ideapreneurs are in a Relationship Beyond the Contract™ with 500 customers in 31 countries. How can I help you?

Author InfoPriya T G