"Telecommunications Management Network (TMN)"
Telecommunications Management Network (TMN) Definition The telecommunications management network (TMN) provides a framework for achieving interconnectivity and communication across heterogeneous operating systems and telecommunications networks. TMN was developed by the International Telecommunications Union (ITU) as an infrastructure to support management and deployment of dynamic telecommunications services. Overview The telecommunications industry is seeing rapid and ongoing change. With emerging technologies, deregulation, and increased consumer demand, companies are presented with a wide range of opportunities and challenges. As companies unify their networks and systems, they must merge new technologies and legacy systems. This is no small task, as a company's networks may encompass analog and digital systems, multiple vendor equipment, different types of sub networks, and varied management protocols. Why TMN? To survive in a highly innovative and competitive telecommunications market, use of a robust architecture for network and service management is a must. TMN provides a framework for achieving interconnectivity and communication across heterogeneous operations system and telecommunication networks. To achieve this, TMN defines a set of interface points for elements which perform the actual communications processing (such as a call processing switch) to be accessed by elements, such as management workstations, to monitor and control them. The standard interface allows elements from different manufacturers to be incorporated into a network under a single management control. The TMN Framework: • ensures interoperability • ensures scalability • is mature (large amount of telecom standards in GDMO) • provides security Operations system Trunk is a logical connection between two switching nodes. Periodic measurement of loss and S/N of all trunks. Failing threshold set for QoS; failing trunks removed out of service before the customer complains Trunk Test System Telecommunication Network Transmission Transmission Test System Test System Nodes Voice Voice Public Switch Public Switch Transmission Links Figure Operations System for Network Transmission Traffic monitored at switch appearance Call blocking statistics obtained. Traffic and call-blocking statistics provide data for planning Importance of Operations, administration, mainte-nance, and provisioning . Traffic Measurement System Data / Telecommunication Network Traffic Traffic Counter Counter Nodes Router / Switch Router / Switch Transmission Links Figure Operations System for Traffic Measurement TMN Conceptual Model: NMS manages the data communication and telecommunication network. The telecommunication network consists of switching exchange and transmission system network elements. It is primarily the WAN of communications. The switching sytem contains both analog and digital system. Hence the transmission system consists of twisted pair, co-axial, fiber optics and wireless. The data communication network components consist of LANs, bridges, routers, gateways and host. The workstation attached to the data communication network is a distinct element of TMN. ITU-T recommendation M.3010 defines TMN as a Conceptually separate network that interfaces with one or more individual telecommunication networks at several points in order to send th receive information to or from them and control their operation. Telecommunications Operations Management Operations Operations System Network System System NMS Workstation Data Communication Network Switching Transmission Switching Transmission Switching System System System System System Voice Voice Telecommunication Network Figure TMN Relationship to Data and Telecommunication Network The figure shows two service providers A and B. customers buy services from service providers and providing high quality customer service should be a key part of a service providers business. The service providers sell telecommunication services to customers who mean that telecommunication network needs to be operated efficiently and economically. The interfaces associated with various functions and services have been standardized in the TMNs model. Notice the three interfaces Q3, F and X. Q3 is a interface between operation system and network element. F is a interface between a workstation and an operations system. Information exchange between operations system with in a TMN is accomplished with the Q3 interface, where as OSs belonging to different TMNs communicate via the X interface Service provider A Service provider B Customers Customers Services provided by Services provided by Telecommunications Telecommunications Provider Provider Network Network Q3 Q3 Operations Systems X Operations Systems Q3 Q3 OS OS OS OS F F Workstation Workstation System Operators System Operators Figure TMN Conceptual Model TMN Recommendations from ITU-T Figure Standard relation TMN architecture TMN Architecture Functional Physical Informational Architecture Architecture Architecture Figure TMN Architecture Functional architecture: Functional modules or blocks Reference points between modules Physical architecture: Physical blocks Physical interfaces between the blocks Informational architecture: Information exchange between entities Object oriented Functional Architecture The logical function blocks of the TMN are shown in Figure 1.3 and descriptions of the function blocks are given. OSF—Operations systems function QAF—Q adapter function MF—Mediation function WSF—Workstation function NEF—Network element function DCF—Data communication function Fig. TMN logical function blocks. In Figure the solid circles are part of the TMN. The dotted circle represents a requirement that is not strictly a TMN logical function block; however, it is essential to consider this in order for communicating management information between these logical function blocks. Each of the logical function blocks will include data communication functions and in addition a data communications network may be required. Operations systems function (OSF) block represents the processes associated with management of the telecommunications network. As the purpose of management in this context is to monitor and control the resources so that telecommunications services provided by the network meet the quality objectives, the activities OSF performs include: obtaining management information such as alarm status of managed entity, performing the required information processing activities on the retrieved management information (e.g, correlating the alarms to determine the root cause), and directing the managed entities to take appropriate corrective actions (e.g., request to perform a test). Mediation function block, as the name implies, performs the necessary functions to mediate the information exchange between two other function blocks. For the current application of TMN, it is between the OSF and NEF. As such, it may include capabilities to store, filter, and adapt the data to the expectations of the two sides being bridged. For example, the information required by the OSF may be more refined than individual entity specific information such as an alarm from terminating end points. Consider the case where four network elements are connected together in a ring configuration. Assume that the network elements are provided by one supplier. If the physical connectivity is lost between two of the NEs, instead of issuing several alarms for every affected termination, mediation function may correlate and report one alarm with the probable cause being a fiber cut and pass it to the OSF.7 Workstation function (WSF) block supports the translation required to present TMN defined management information to a human user and to translate from user requests to representations used by TMN entities. This book will not address in detail WSF for the following two reasons: (1) the work on WSF itself and how a workstation interfaces to TMN is still preliminary and is evolving; and (2) the emphasis for this book is to address machine to machine interactions. Physical Architecture: A TMN physical block could be an embodiment of one or more blocks, besides it equivalent functional block. Operations systems are embodiments of the TMN operations system function. This function is connected to the mediation device placing the mediation function on a data communication network. The data communication network is the physical implementation of the data communication function, which, to repeat, is not a function block but a TMN function, DCF. The network elements, Q adaptor, and workstations reflect their respective TMN functions. The Q F and X TMN interfaces between the physical devices are shown in figure. The Q3 interface is used between the OS and an NE or a QA. The Qx interface is used between an MD and a QA or an NE. an example is an MD being a proxy server communicating with legacy systems via a QA interface. The F interface is implemented to connect a workstation to TMN. The X interface used between OSS belonging to two different TMNs. Operations System (OS) TMN X Operations System (OS) X/F/Q3 Data Communications Network (DCN) Workstation F/Q3 F Mediation Device (MD) Q3 Qx Q3 Data Communications Network (DCN) Qx Qx Network Network Q Adapter Q Adapter Element Element (QA) (QA) (NE) (NE) Figure TMN physical Architecture Information Architecture: The TMN information architecture initially adopted the OSI management information architecture. How ever with the wide acceptance of the internet SNMP, deployment of both models in TMN is underway. OSI informational model is object oriented while SNMP model is scalar. The figure shows the information exchange between the two types of entities. The manager performs operations or makes requests from an agent. The agent executes the operations on the network elements that it is managing and sends responses to the manager. The agent also sends unsolicited messages to the manager indicating alarm events. Operations / Requests Manager Responses Agent Notifications / Traps Figure TMN Information Architecture The information architecture should transport information reliable across functional boundaries. There are two types of communication services between interfaces: interactive file-oriented Interactive is supported in OSI by the Common Management Information Service Element (CMISE) over the Remote Operations Service Element (ROSE). In the internet distributing computing environment, the function as handled by Remote Procedure call (RPC). The File-oriented category is supported by File Transfer Access Management (FTAM), In OSI and on the internet by File Transfer Protocol (FTP). TMN Management Service Architecture Another functional model of TMN is based on the services provided in a TMn environment. The lowest layer is the network element layer, Comprising network elements such as switches, routers, bridges, and transmission facilities. The second layer is the element management layer, which manages network elements. The third layer is the network management layer which manages the network. The service management layer is concerned with managing the services provided by a network service provider to customers or to other network service providers. They include services such as billing, order processing, complaints, and trouble ticket handling. The top layer is the business management layer. It is concerned with managing the operations of a communication business, human resource needs, project management. The TMN reference point between the various service layers is q3. It is the standard interface between the operation system, network element, and mediation functions. TMN management services are classified by OSI system management functional area. These areas are the five OSI application functions: Business Management Configuration management Fault management q3 Performance management Service Management Security management q3 Accounting management Network Management q3 Element Management q3 Managed Network Element An Integrated View of TMN The four TMN management services – business, service, network, and element – are at the top of the hierarchy they invoke the system management functions defined as the five components comprising the system management functional areas: configuration, fault, performance, security & accounting. The management applications in the system functional areas perform either system management functions or TMN functions. TMN functional block OSF, WSF, NEF, MF and QAF consists of TMN functional components such as the NMF and MIV. The system management functions include object management and alarm management. System management functions and TMN functions invoke the primitive services. Figure also shows the OSI primitive services of M-GET, M-SET, and so on. Equivalent SNMP services are GET-REQUEST, SET-REQUEST, and so on. TMN is the distributed environment. The applications communicate remotely with the communication transport service by means RPC. In the OSI model, the RPC is accomplished with ROSE and ACSE. The former does the remote operation and the later establishes and releases the application association. In SNMP management model, the remote operation is accomplished by using the RPC and TCP/IP. TMN Management Services Business Service Network Element Management Management Management Management System Management Functional Areas Configuration Fault Performance Security Accounting Management Management Management Management Management DCF TMN Function Blocks OSF WSF NEF MF QAF System Management Functions TMN Functional Components Object Alarm NM Presentation Management Management Manager Function CMISE M-GET / M-SET / GET-REQUEST SET-REQUEST M-CREATE Remote Procedure Call ACSE ROSE Communication Transport Service (OSI Presentation Layer) Figure 11.13 TM N Services and Functions Implementation issues Two Forums have actively promoted implementation of TMN: The ATM forum NMF (network management forum) Implementation using OMNIPoint: An example of TMN architecture realization is presented in figure; it shows the TMN logical layered architecture and a physical realization of it. Each layer consists of several management systems that provide the various services. The layered architecture shows the TMN q3 reference points and the physical realization shows the corresponding Q3 interfaces. The NMF is an industry sponsored forum it has developed a program called the Open Management Interoperability Point (OMNIPoint). The objective is to help companies’ implement management standards for a broad range of suppliers’ equipment. It has developed documents that specify mapping between the internet and OSI standards to help TMN implementation in a hybrid management environment (NMF) TMN Logical Physical Realization of Layered Architecture TMN Architecture Customer Business Service Management Management q3 Service Q3 Performance and Ref. Point Details Billing Data Service Service Mgmt Service Mgmt Service Mgmt Management Tarif/Charging Provisioning Other Service- q3 Service Q3 impacting Ref. Point Configuration Events Network Net Mgmt Net Mgmt Net Mgmt Management Routing Admin Traffic Admin Restoration q3 Equipment Q3 Equipment Ref. Point Configuration Alarms Net Element Element Net Element Net Element Trans Eqpt Management Cust Admin Switch Mgmt Mgmt Figure 11.14 TM N Re alization Example (NM F)