**5.2 Centralized architecture**

The initial architecture is centralized and enables a selective monitoring of consecutive operations related to SLA and it verification. This system allowed demonstrating the steps of the verification operations, the different KPIs and KQIs of service, and some operational limitations (Raouyane B. et al., 2011).

In order to simplify SLM&M, the number of exposed web services has been limited to eTOM level 3 business processes. Naturally processes of level 4 are implemented via appropriate methods within web services.

entities. In addition, a BPEL (Business Process Execution Language) (Poornachandra, Matjaz, and Benny, 2006) component has been designed to orchestrate the various processes

The three modules of the monitoring system are: WS-Resource, WS-Service, and WS-Customer; each one exposes a set of web services specified using WSDL (Web Services Description Language) (W3C Recommendation, 2007). These web services are invoked and synchronized by the central BPEL component that provides moreover tools such as a web interface that tracks performance of overall network, SLA operation, processes execution and monitoring of physical and logical network resources (Figure 9). The SLM&M (Service


The initial architecture is centralized and enables a selective monitoring of consecutive operations related to SLA and it verification. This system allowed demonstrating the steps of the verification operations, the different KPIs and KQIs of service, and some operational

In order to simplify SLM&M, the number of exposed web services has been limited to eTOM level 3 business processes. Naturally processes of level 4 are implemented via appropriate

and to organize the desired operations (Figure 9).

Fig. 9. Implementation architecture.

**5.2 Centralized architecture** 

methods within web services.

limitations (Raouyane B. et al., 2011).

Level Monitoring and Management) architecture contain:


its functions and information processing.

Fig. 10. SLM&M Centralized architecture.

Before analyzing the different SOA modules, it is useful to introduce the interfaces between SOA modules and network. These interface agents take (Figure 10) in charge low-level detections and calculations and transmit their results to the SOA modules via dedicated socket interfaces:


The SOA Modules expose each eTOM layer:


eTOM-Conformant IMS Assurance Management 65

incorporate mechanisms for monitoring locally but also to allow a local correction of QoS

The new functional architecture of SLM&M (Figure 12) consists therefore of two main


• Is distributed, and contains a set of agents and probes that are able to recover all data in real time (signalization, logging, reservation, configuration, policy, routers status, etc. ..) and implements all Resource layer processes for SLA verification: Resource Data Collection & Processing (RDC&P) and Resource Performance Management (RPM), which are related to each IMS layer (Access, Control, Service). • Contains a set of processes that are functional in ordering and other SLA operations of WS-Resource. Also, a synchronization module that is necessary for detection and control of events in the network, such as planning activities and communications on one hand between the distributed modules (first part) and also

degradation and anomalies.

Service Inventory. - Monitoring Layer:

between Web services exposed (Layer).

Fig. 12. The main layer of SLM&M: Monitoring, Assurance.

modules:

responsible for SLA verification. It retrieves the KQIs of the currently delivered service, loads the customer profile and subsequently detects any SLA violation.

	- Show messages exchanged between web services (XML/SOAP) and modules.
	- List performance indicators collected from the network layer entity
	- Monitor the activity and performance of physical resources such as network routers and logical entities such as CSCFs and the HSS (Home Subscribe Server).
	- Check the provisioning chain of QoS management: PCRF, PCEF.
	- View the results of the audit and SLA verification, the customer class, and values of KQIs.
