Next Generation Network Management Technology

Today's telecommunications networks are becoming increasingly large, complex, mission critical and heterogeneous in several dimensions. For example, the underlying physical transmission facilities of a given network may be "mixed media" (copper, fiber-optic, radio, and satellite); the sub networks may be acquired from different vendors due to economic, performance, or general availability reasons; the information being transmitted over the network may be "multimedia" (video, data, voice, and images) and, finally, varying performance criteria may be imposed e.g. data transfer may require high throughput while the others, whose concern is voice communications, may require low call blocking probability. For these reasons, future telecommunications networks are expected to be highly complex in their services and operations. Due to this growing complexity and the disparity among management systems for individual sub networks, efficient network management systems have become critical to the current and future success of telecommunications companies. This paper addresses a research and development effort which focuses on prototyping configuration management, since that is the central process of network management and all other network management functions must be built upon it. Our prototype incorporates ergonomically designed graphical user interfaces tailored to the network configuration management subsystem and to the proposed advanced object-oriented database structure. The resulting design concept follows open standards such as Open Systems Interconnection (OSI) and incorporates object oriented programming methodology to associate data with functions, permit customization, and provide an open architecture environment. INTRODUCTION The size, complexity and heterogeneity of today's networks makes network management one of the most critical elements in the successful provision of telecommunications network services. Industry leaders, universities, and government research centers have recognized the magnitude and the importance of network management problems. They have been investing millions of dollars for research and develop network management solutions. For example, Hughes Network Systems (HNS) is well aware of the importance of network management in their overall product strategies. Because of this, they have long been a leader in providing innovative network management products. They are now embarking on an effort to develop a next generation of network management systems. As part of this effort, HNS together with a team from the Institute for Systems Research (ISR) at the University of Maryland at College Park, developed a prototype system for managing HNS Integrated Satellite Business System (ISBN) systems. The team at the ISR, which is comprised of faculty, research scientists and students from Electrical Engineering, Computer Science, Operations Research and Business and Management, was drawn from a research group dedicated to the development of advanced technology for network management. This research effort is supported by HNS, Maryland Industrial Partnership Programs (MIPS), and by NASA grant #NAGW-2777S for the establishment of a NASA Center for the Commercial Development of Space (CCDS). A network management system is a hardware/software system for planning, coordinating, operating, monitoring and controlling a telecommunications system. The recently developed prototype network management system generally addresses ISBN network management and is specifically oriented to the configuration of LANAdvantage systems (Figure 1). FIGURE 1. LANAdvantage Network Configuration. TM ISBN is a Wide Area Network (WAN) solution which employs a "star" network topology. Using this system, multiple geographically-dispersed remote sites can communicate over a satellite link through a central hub. In a traditional WAN environment, inter-Local Area Network (LAN) communication has been supported by gateways or routers which convert LAN protocols to WAN protocols. LANAdvantage eliminates the need for a gateway or router, allowing LAN users to communicate directly to an ISBN Personal Earth Station (PES). The hub and each remote site consist of a complex hierarchy of hardware and software objects. A remote has many Data Port Clusters (DPCs), each DPC has many Line Interface Modules (LIMs) and each LIM has many ports. Similarly, the hub hardware has a similar but larger containment hierarchy consisting of many network groups, many networks, many DPCs, many LIMs and many ports. Sessions are established between a hub port and a port at a remote site via Inroute and Outroute satellite channels. Inroutes are the satellite channels that are used by the remote sites to communicate with the hub. Outroutes are the satellite channels that are used by the hub to communicate with the remote sites. The system developed by the HNS/ISR/CCDS team (Figure 2) allows the user to view and access information about both the hub and remote site in a variety of ways. FIGURE 2. Overall Screen Layout: Completion of Task is indicated by All Buttons in Check-List Being Green. It integrates both query and data update capabilities within a single user interface. Two advanced techniques are used for representing and manipulating hierarchical data: a treemap and treebrowser. The primary function addressed by the system is the setup of a hub-to-remote site session. To accomplish this task, a set of sub tasks must be carried out. The sub tasks involve the specification of a network, DPC, LIM and port, as well as related parameter values for both the hub and remote. A set of buttons is displayed across the top of the screen. The buttons represent a sub task check is. This checklist orientation allows the operator to maintain a global perspective relative to the accomplishment of the ultimate task, namely, the specification of a hub-to-remote site session. All data accessed by the system is stored within an object oriented database system. Network Management Technologies for the 9 0 ' s The HNS/ISR/CCDS prototype system embodies innovative research carried out into two key network management technologies: • object oriented (OO) databases • advanced graphical user interface methodology for network management. It is now generally accepted that the OO paradigm is the database technology of choice for future network management products. Success with the use of OO techniques and databases within Computer Aided Design (CAD) systems provides ample evidence that this approach should provide significant advantages within network management as well. Furthermore, standards bodies have committed to the OO model for telecommunications network management. The ease with which an operator interacts with a computer system clearly depends most critically on the structure of the user interface. By developing new graphical user interface techniques the team hoped to address many of the negative characteristics of current configuration management systems. The use of informative, intuitive graphical displays should provide the user with a better understanding of the configuration tasks being addressed which in turn will lead to faster task completion and higher quality decisions. Proper graphical representation of the overall problem to be solved will allow the user to see "the big picture" and make it less likely that the user will become confused when navigating through the list of tasks. By integrating flexible query facilities within the data entry environment, the user will be able to gather decision enhancing information to make faster, higher quality decisions. RESULTS AND ANALYSIS This research and development effort resulted in a new data model for network management, a technique for embedding rules and constraints within OO database systems, and in a two graphical user interface techniques for representing and manipulating hierarchies. These results are now summarized. A New Object Model for Network Management Prior to the creation of any database, a data model must be developed. The construction of a data model is part art and part science -the “essence" of a real-life system must be captured in a set of formal data modeling constructs. In the case of telecommunications networks, the construction of an appropriate model for representing all relevant data is a challenging problem (Datta 1993 and Harista 1993) whose solution can greatly impact the overall quality of the system both in terms of the efficiency of carrying out database operations and in terms of the manner in which data can be presented to the user. A comprehensive model (Figure 3) was developed which captures not only configuration management data but also data to be used in carrying out other network management functions. Some specific features of this model are: • a very general link model that allows for the representation within a common framework of a wide range of link types, including satellite links, point-to-point physical terrestrial links and pointto-point virtual links such as calls and sessions; • a flexible approach to handling protocol layers within heterogeneous networks, in other words, this methodology allows for the ready analysis of complex calls that are routed partially over a satellite network and partially over a terrestrial ATM network; • support for the management of network software, allowing for the tracking of software downloads and reboots, distribution of updates and versions, etc. Since the OO database system is the string that will tie all network management systems together, it is essential to have a solid, well-designed data model upon which to develop all applications. FIGURE 3. Basic Object Classes & Inheritance Hierarchy Manage d Object Netwo rk Element Software Event Network Message Operator Log Fault Message Message Performance Message Billing Constraints or Rule Equipments Software Specificatio Application s Optimizatio n hub softwar text editor