UDC 621.395.74:681.32 Policy-based Management for Enterprise and Carrier IP Networking VTakeo Hamada VPeter Czezowski VTakafumi Chujo (Manuscript received September 15, 2000) Policy-Based Management (PBM) will play a key role as a management technology for end-to-end IP-nized integration of enterprise networks and telecommunication net- works. In this paper, we examine PBM and its requirements for managing the new telecommunication network service environment, and propose a scalable new PBM architecture based on relevant research at Fujitsu Laboratories of America. A new development in PBM, called active policy, is illustrated. We expect that the active policy will bring new insights on the integration of PBM and intelligent agent systems, benefiting service management and customer care in the new network service environment. 1. Introduction ferent views of network design and its operation, The Internet has given rise to explosive resulting in different approaches toward network growth of communication demand. The Internet management. Predictable dominance of the In- traffic doubling period of 90 days, also known as ternet in the data traffic and network service Gilder’s law,1) is a clear indication of its huge im- spheres, however, has put the two paradigms in a pact on our society for years to come. In last 5 collision course, and it seems clear that a new years, a new generation of equipment vendors and network management paradigm must be born out carriers has emerged, responding to insatiable of this cultural collision. We at Fujitsu Laborato- bandwidth demand of the Internet users. The ries of America have been engaged in research to Internet has brought a new paradigm of commu- bring forth the vision of the new network man- nication and networked services, and it has also agement paradigm into reality. In particular, we brought a set of new IP-based technologies, new believe that Policy-Based Management (PBM) is technical standards, and new business styles. at the center of this new paradigm. Telecommunication is, in contrast to the In- ternet, a much more mature technology. Since 2. Network management for the new Graham Bell’s invention in 1876, the basic ser- network service paradigm vice paradigm of PSTN (Public Switch Telephone Encounter between the two paradigms has Network) has changed little: a network optimized been one of the driving forces behind several im- for human voice communication. Over the long portant technical developments in late 1990s; years, the telecommunication has served as one Voice over IP, and NGN (Next Generation Net- of the most important pieces of social infrastruc- work), to name a few. The same is true for network ture, responding to the high demand on its management, whose aim is to achieve high reli- reliability and universal availability. ability and accountability of network operations The two network paradigms are based on dif- and services through the use of NMS (Network 128 FUJITSU Sci. Tech. J.,36,2,pp.128-139(December 2000) T. Hamada et al.: Policy-based Management for Enterprise and Carrier IP Networking Management System). In the early stages of the Task Force) standards, along with the telecommu- Internet, there was fairly clear separation between nication management framework, notably TMN the Internet and the telecommunication, both in (Telecommunication Management Network) stan- terms of technologies and management responsi- dards from ITU-T. The challenge of the new bilities. The majority of traffic was still voice, and paradigm is to cast the two existing management the telecommunication network provided WAN in- frameworks into a new, unified framework, capa- frastructure, upon which the Internet was built ble of end-to-end management of both data and as an overlay. multimedia traffic. With the growth of the Internet, the volume of data traffic surpassed that of voice traffic, and 3. Policy-Based Management it has become common to build an all IP-based Policy-Based Management (PBM) has at- backbone network, which is overlaid directly on tracted significant attention both from the SONET or WDM (Wavelength Division Multiplex- industry and the academic research community ing). The Internet is quickly becoming an essential in recent years, as it has been recognized that PBM public network infrastructure, replacing some of can effectively provide a good means to solve the the roles of the telecommunication network. In puzzle of integrated IP/telecom management. other words, these two networking paradigms – Early works on PBM include Sloman3) and others Internet and telecommunication network – will in early 1990s. Inspired by DEN (Directory En- merge into a new telecommunication infrastructure. abled Network)4) initiative by Cisco and Microsoft, Moridera et al.2) suggests that the future tele- works on PBM followed in IETF Policy WG and communication service environment will look like DMTF, forming a strong technical trend in the IP a virtual network server, which consists of a set of networking community. Although the center of application specific servers running on IP-based PBM activities is in IP networking, PBM can be application protocols interconnected by a high- applied to wide range of control and management speed all optical network. The virtual server issues both in IP networks and telecommunica- provides access to actual servers and service/net- work management support (Figure 1). In this new paradigm, network/service management it- Stream media Virtual server self is a service, provided by a set of specialized E-commerce Publication servers. Though it resembles the Internet, this Application new telecommunication must provide the good server characteristics as found in today’s telecommuni- cation network, i.e. high reliability and universal availability. Photonic core network Virtual Network management is one of the key tech- router nologies needed to fulfill the above requirements. In other words, a new paradigm for network man- agement is also needed, in order to address the Load Edge node Protocol Gateway balancing conversion requirements arising both from the Internet side Access Access Access and the telecommunication side of the new tele- Access server communication infrastructure. In particular, the new network management paradigm will incor- porate the Internet management framework Figure 1 New network service environment. consisting of related IETF (Internet Engineering FUJITSU Sci. Tech. J.,36, 2,(December 2000) 129 T. Hamada et al.: Policy-based Management for Enterprise and Carrier IP Networking tion networks. requests a policy decision made by the PDP. In Figure 2 illustrates the IETF standard PBM IETF, protocols for the standard reference model architecture.5) The figure illustrates realization have been standardized: LDAP (Light-weight Di- of the standard architecture in typical IP man- rectory Access Protocol) for the communication agement environment as offered by Fujitsu between the policy-repository (LDAP server) and SystemWalker. The architecture is designed in PDP, and COPS (Common Open Policy Service) such a way that high-level management knowl- for the communication between PDP and PEP. edge is captured by policy rules, which are stored A major motivation for developing IETF stan- in a policy repository, known also as directory serv- dard PBM has been to give remedy to SNMP er. In general, the policy rules have the following (Simple Network Management Protocol)-based form. management framework, whose usage has been limited primarily to monitoring. In a historical IF policy_activation_codition THEN policy_action perspective, this is a result of rapid deployment and technical maturity of IP network, to which IP The policy activation condition describes the management technology needed time to catch up. condition when the following policy action is to be We think the following technical characteristics activated. For example, monitoring events, which of PBM are particularly noteworthy from the report network state, node state, or traffic type at standpoint of the integrated IP/telecom network ingress router, can trigger a policy action result- management. ing in provisioning of the network resources. Once Built-in network intelligence: through its these policies are defined and deployed at the information model and policy rules, PBM provides policy-server (PDP, Policy-Decision Point), they are richer context for more intelligent operation and further translated and downloaded to correspond- management for increasingly complex IP network ing network devices (PEP, Policy-Enforcement than what is available in IP networks today. In a Point) to put the policies in effect. This interac- crude sense, each policy rule can be seen as a frag- tion between PDP and PEP works in the opposite ment of a distributed intelligent information direction also. For example, a piece of policy is system, of which expert knowledge is solely fo- uploaded from PEP to PDP, so that the PEP cused on IP network operation and management. The above feature has been emphasized as one of the advantages of PBM, in particular in Management applications Policy the original DEN proposal. From our point of view management tool (optional) of the integrated IP/telecom network manage- (LDAP) Policy server Directory Policy ment, we believe that the following three features server(RDB) repository will be important for the future development of (LDAP) Policy decision PBM. Status Dynamic point (PDP) monitoring control Integration of control and management: Access (COPS) the same information