Network Management Structure - Assignment Example

Network Management Definition: Network management consists of different aspects of network monitoring and control. A network management system performs among other things the task/service of configuration of the network, guaranteeing its proper functioning, maintenance, security control, collection and archiving of data and fault diagnosis. Keywords Policy-based Networking, Hierarchical Management, IP Differentiated Services Introduction Policy Based Network Management (PBNM) is not an ordinary subject or simple stream of information, it requires a good deal of search. This subject remained a focus of professionals’ attention during last decade. Now PBNM is thought to be a source of managing IP based networking as well that assures a better quality and high integration. As a matter or principle, policies are seen as a source of extending and guiding different network attributes through system. Policies extend logic of networking and system and help these to be adaptive and changing for new business needs. In this way overall system is tailored according to individual needs. By definition a policy is derived from various corporate goals with the help of different service levels and agreements. Policies need to be specify, flexible and should be applied without coding through automated agents. Policies are always persistent and can be easily modified if there is any need. Policies also bring various changes in the dynamics of business as a catalyst if extra ordinary innovation is exercised. An example of services: Network Management System Net work management system includes many network management stations (NMSs) that communicate with different agents at various components through utility of different protocols like SNMP, CMIP etc. Policy Agents for Management Main process of Policy Based Network Management has two types of Obligation and Authorisation. Obligation is for managers to must do certain things where as authorization refers the managers’ limits for that they have been authorised by senior management. Practically managers get information from and they perform various controlling acts, these actions are called subjects. Software subjects are declared interfaces those allow actions to be performed on different interfaces for writing, reading and renaming. The reason and objective of using authorization policy is to protect different objects and protocols at security stations. As shown by the figure below obligation and authorization policies go side by side and both monitoring and control happen between subjects and targets simultaneously. Policy-based Management in the Research Community There are different researches being carried on by various scholars with different expertise in computers and management sciences who discovered numerous concepts of domains and policies in the context of generic management architecture.[Slom94] Figure1: With the assumption of management and infrastructure going together where policies are objects and managers applying such policies are subjects with targets as managed objects. In fact in this procedure of applying technology with minimum human support policies are isolated from automated managers and policies also support change and adaptively to new system needs and applications. In these systems domains offer a framework that does partitioning of responsibilities of group members. Here domains are mainly objects that support and manage the list of different references to the member managed objects. [Slom89] In figure 1, it can be seen that a generic structure is defined for business management that consists of: “a) Communication services for communication between applications as well as between applications and managed objects, b) Object services for class and instance administration – the architecture assumes a distributed objects framework such as e.g. OMG CORBA, c) Distributed processing services supporting interaction between distributed components, d) Common management: services which support the fundamental concepts of domains, policies and monitoring and e) The management applications which are capable of interpreting and applying policies.” [Wies94] In Policy-based Distributed Management System Architecture [Slom94]. The policies mentioned below are identified in [ICpol], while [Wies94] these also explain the list of different factors for the classification purpose of these policies. Authorization Policies: Authorization policies can be positive or negative ones. Authorisation policy defines the limits of a subject that what a subject (manager) can do and what a subject is not allowed to do. These policies restrict or allow access and reach of subject to the control and control policies. Obligation Policies: These policies are related to operations and give mandate for the ‘must do’ action to subject. Obligation policies restrict subject to perform and achieve some specifically targeted objects. Here event triggered policies are positive obligation policies. Refrain Policies: Not a surprise to know and have such policies of avoidance or reference along with authorization and obligation policies. Refrain policies guide and give command to subject about those actions which cannot be performed by subject in any case. These policies are to define the list of ‘forbidden’ elements in whole network. Delegation Policies: Like in normal business setup and manual working there is a need of some delegation of power and authority, in network management there is a concept fo delegation policies which specify the types of actions and command a subject must perform and actions which a subject is allowed to delegate to other. Delegation policies can also be of positive or negative nature. It also discusses the role of refinement of high level policy and make it more specific and to the point. [Moff93] Partitioned Targets: Partitioned targets are also important in any network some target of lower level policy may represent or be the part or sub set of a higher level policy. Targets’ complexity makes the situation more complex in many cases. Goal Refinement: Focusing and restructuring goals from lower to upper level or from upper level to lower level. This relocation, enhancement or tuning of goals is called goal refinement. Arbitrary Refinement of Objectives: Some times arbitrary refinement of objectives is also required and for this purpose the goals and targets can be different in style but overall goal will be same. Procedures: Procedures are defined by a set of systematic commands helpful in achieving overall objectives. Procedures can be altered if needed or required. Delegation of Responsibility: Delegation of responsibilities is always needed in business and in proper formulation and delegation such as division of work and tasks is very important in all respects. Related work in the area of policy hierarchies is known for the work of Wies.[Wies94], “Corporate or high level policies, Task-oriented policies, Functional Policies and Low-level Policies. A declarative, object-oriented language has also been developed for specifying policies for the management of distributed systems, including constructs for specifying the basic types of policies described before.” [Ponder] Considerations on Policy-based Network Management Better than Conventional Systems: “While most research work on policies has concentrated in necessary fundamental aspects such as classification, policy language, conflict detection and most recently in policy representation and storage, little work has been done in the area of the harmonic coexistence of policies and traditional, possibly hierarchical, management systems. Policies, apart from their high-level declarative nature, can be also seen as a vehicle for “late binding” functionality to management systems, allowing for their graceful evolution as requirements change. It is this aspect of policies we find most interesting and we have been exploring the potentiality of designing “policy-aware” management systems, in which a line has to be carefully drawn between “hard-wired” functionality and policy logic.” [Blake98] The most effective benefit of policy based management is the flexibility of this concept that allows managers and company to adjust quickly and accordingly in case of any needs. This system helps companies to gracefully revolutionize their business and entire setups. Policy based network management (PBNM) helps companies to remove unsuccessful policies and bring new ones in a less period of time. Possibilities of making changes in targets and work plans are also feasible with the helpful PBNM and its logistic support. Many managers like this approach very much as it helps them to hit and achieve their objectives in an easy way and it can change the direction of targets and support efforts in any direction at any time. It further reduces the working and interest conflicts that are famously involved in the destruction of business in my cases. “Conflicting actions do not occur only in policy-based management systems but are potentially possible in any control system which performs intrusive management actions by modifying targets rather than simply observing them. Below we consider aspects of policies, intrusive management and conflicts in different management frameworks. Enterprise networks are typically managed with SNMP, using a relatively simple management architecture consisting of a single, centralized “network management center .The latter supervises network elements located typically in a cluster of local / metropolitan area networks. In this architecture, the elements are typically configured one-by-one, in an isolated fashion, through the supervision of a human network manager and according to an overall network operation policy, which is worked out beforehand. This means that (re-)configuration is infrequent and takes place manually.” (NMC)” Summary: Many of researchers on policy based management have focused on preliminary factors of professional working for example classification of policy, its language, efforts to detect and prevent conflicts during working. Policies can be labeled as ‘late binding’ as function of management system. There is need to distinguish between hard wired functionality and policy logic. Here we have evaluated different features of policy management and their role in network management. References [Blake98] S. Blake et al, An Architecture for Differentiated Services, Informational RFC-2475 December 1998. [Georg99] P. Georgatsos, D. Makris, D. Griffin, G. Pavlou, S. Sartzetakis, Y. T’Joens, D. Ranc, Technology Interoperation in ATM Networks: the REFORM System, IEEE Communications, Vol. 37, No. 5, pp. 112-118, IEEE, May 1999. [ICpol] Imperial College, Policies for Network and Distributed Systems Management, http://www-dse.doc.ic.ac.uk/policies/. [Moff93] J. Moffett, M. Sloman, Policy Hierarchies for Distributed Systems Management, IEEE Journal on Selected Areas in Communications, Vol. 11, No. 9, pp. 1404-141, December 1993. [Ponder] N. Damianou, N. Dulay, E. Lupu, M Sloman, Ponder:A Language for Specifying Security and Management Policies, Imperial College Research Report DoC 2001, January 2000. [Slom89] M. Sloman, J. Moffet, Domain Management for Distributed Systems, Integrated Network Nortel: Enterprise Network Management System http://products.nortel.com/go/product_content.jsp?segId=0&parId=0&prod_id=25520&locale=en-US IEEE/IFIP Network Operations and Management Symposium (NOMS)http://www.noms2006.org/ Read More