Internet Draft D. Wagner (Fraunhofer), I. Miloucheva (Fraunhofer), Ch. Niephaus (Fraunhofer), A. Flitzikowski (UAM), M. Wachowiak (ITTI), P.A. Gutierrez (Telefonica) D. Hetzer (Media Broadcast GmbH) Expires: April 30, 2009 November 30, 2008 Dynamic policy specification and management for heterogeneous Internet environment draft-wagner-dynamic-policy-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 30, 2009. Abstract This document presents requirements and architecture for dynamic user-centric Quality of Service (QoS) policy specification and management in heterogeneous Internet environments. The hierarchical policy specification is based on mapping and refinement of policies at business, intermediate, operational and configuration level. The QoS policy request are selected for heterogeneous network environment considering the restrictions of the users as specified in SLAs and identity management facilities. Wagner Expires April 2009 [Page 1] INTERNET-DRAFT Dynamic policy specification November 30, 2008 The user is enabled to require QoS for specific network and infrastructure selections, as well as to optimise the network selection based on given criteria. The dynamic policy specification and management facilities for heterogeneous Internet infrastructures is based on policy management interfaces for different actors (users, service providers, network operators), usage of ontologies for policy mapping and consistency check, flexible network selection for QoS policy definition, as well as policy data mining system including repositories for policies at different levels and their mapping. Particular integration of the discussed facilities is performed in the framework of the NETQOS policy management system. Table of Contents 1. Introduction................................................ 3 2. Terminology used in this document........................... 4 3. QoS Policy specification and interfaces ................... 5 3.1. Requirements for dynamic QoS policy specification by different actors ........................................... 5 3.2. QoS policy framework for heterogeneous environment ......... 6 3.3. Hierarchical policy mapping ................................ 7 4. Policy data mining ......................................... 8 5. Integration of dynamic QoS policy specification and management in NETQOS ....................................... 10 6. References.................................................. 13 7. Author's Addresses.......................................... 13 8. Intellectual Property Statement............................. 14 9. Full Copyright Statement..................................... 15 1. Introduction In this document requirements and facilities for dynamic QOS policy specification and management for different policy actors (users, service providers, network operators) for heterogeneous Internet environment are discussed. These facilities are particularly integrated in the NETQOS QoS policy management system [1]. The QoS policy specification framework is based on business policy specifications and their hierarchical refinement to intermediate, operational and configuration policies [2]. Business QoS policies for heterogeneous network environment enable the users to configure dynamically QoS mechanisms at transport and Wagner Expires April 2009 [Page 2] INTERNET-DRAFT Dynamic policy specification November 30, 2008 network entities according to their QoS and network preferences considering technology and vendor dependent capabilities of the entities [3]. The QoS policy requests are mapped to policies considering the heterogeneous network environment, network restrictions of the users derived by SLAs and identity management, as well as strategies for selection of specific networks and optimization of network selection based on given criteria. The QoS policy specification and management framework includes: - Policy management interfaces for different kinds of actors to specify dynamically QoS policies for heterogeneous network considering SLA restrictions and identity management interactions; - Repositories for policy data mining allowing storage and refinement of business policies to intermediate and operational policy specifications for heterogeneous Internet environment. The QoS policy framework for heterogeneous Internet environment considers the current IETF standardisations, e.g. Policy Core Information Model (PCIM) [4], the Common Information Model (CIM) [5], QoS Policy Information Model (QPIM) [6] and QoS data path mechanisms [7]. The policies for heterogeneous Internet environment allow dynamic selection of application QoS levels by the actors and mapping of selected QoS to the operational QoS mechanisms of heterogeneous networks considering different strategies for network selections. 2. Terminology used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [8]. Abbreviations used in the following text: APM - Actor Preference Manager POLD - Policy Descriptor APA - Automated Policy Adaptor MoMe - Monitoring and Measurement infrastructure NetAgent - Component for automated configuration of mechanisms at network devices TransAgent - Component for policy configuration of mechanisms at transport entities. CM - Context Manager monitoring tool interactions HQPIM - Heterogeneous networks QoS policy information model PCIM - Core Information Model QPIM - QoS Policy Information Model Wagner Expires April 2009 [Page 3] INTERNET-DRAFT Dynamic policy specification November 30, 2008 SLA - Service Level Agreement QoS - Quality of Service GUI - Graphical User Interface This Draft considers the terminology for Policy-based management [9] and extends it to specify QoS policy management framework and interaction for heterogeneous network environment. Discussed framework is related the QoS policy information model for heterogeneous network environment (HQPIM) [3]. 3. Policy management interfaces 3.1. Requirements for dynamic QoS Policy specification by different actors Dynamic specification of QoS policies is required for several kinds of actors (network operators, service providers, users) to define and automatically configure in real-time manner their specific preferences for QoS and resources in heterogeneous Internet infrastructures according their needs [2], [3]. The QoS policy management interfaces allow the policy specification by actors (users, service providers, network operators) for specific network contexts and Internet infrastructures. The policies can be specified to support optimal and cost efficient resource usage in heterogeneous Internet environment, as well as enhanced QoS guarantees according to business QoS preferences of the particular actors for particular network infrastructures. The QoS policy specification in heterogeneous Internet environment depends on the SLAs and the restrictions of the actors for service access on the particular networks. These restrictions are obtained considering SLAs and identity management facilities, e.g. SLA and identity repositories. The dynamic QoS policy specification and provisioning depends on the kind of identity management architecture and the regulations between different providers for QoS policy specification in heterogeneous Internet environment [10]. Identity management in heterogeneous Internet is based on different strategies, such as Gateway (Key-store), Passport (Wallet Garden), Single-Sign-On, federative and User centric identity management strategies. Dependent on the requirements of the policy actors (users and providers), the QoS provisioning for the particular actors and applications is automatically configured and adapted for the selected network infrastructure considering actor and SLAs restrictions. The basic interactions for dynamic QoS policy specification are shown in figure 1: Wagner Expires April 2009 [Page 4] INTERNET-DRAFT Dynamic policy specification November 30, 2008 +--------------+ +------------+ +-------------------------+ | Service Level| | Identity | | QoS Policy management | | Agreements | | Management |--| Interfaces for actors | +--------------+ +------------+ +-------------------------+ | | | Consistency check | | +--------------+ |-------------------------+ | | Actor | |SLA/Identity restrictions| | | restrictions | |-------------------------| +------------+ +--------------+ | QoS policy | |Actor QOS | | request | | policy | |-------------------------| | data base | | Preferences for | +------------+ | network | | | environment | +--------------+ +-------------------------+ | Intermediate | | Policy storage and | | policy |-----------------| access | | repository | +-------------------------+ +--------------+ | | +---------------------------------+ +---------------+ | Learning component for usage | | Operational & | | and optimisation of | | configuration |----------| heterogeneous Internet networks | | policies | | networks | +---------------+ +---------------------------------+ Figure 1: Interfaces for dynamic QoS policy specification by different actors and their interactions In the identity enabled policy management for heterogeneous networks, the policy actor (user, customer, service provider) can define his own policies for QoS of the application and preferred usage of networks. Dependent on the specific QoS management scenario, the user can set his preferences for specific QoS guarantee level of applications at different networks, bandwidth reservation options [5], selection of QoS measurement facilities for applications and networks dependent on the network [2]. The policies of the service providers and network operators are used to offer default usage for the users (customers), but are not obligatory for the users. Identity management for policy actors involves the restrictions of the user access based on the related SLAs, services and policies of the actors. Wagner Expires April 2009 [Page 5] INTERNET-DRAFT Dynamic policy specification November 30, 2008 Benefits of the identity enabled QoS policy management architecture for more efficient QoS policy support in heterogeneous Internet environment are: - Restricted access based on identity and SLA information; - Consideration of identity information for QoS policy specification; - More efficient data mining considering SLAs, identity, accounting and other policy parameter descriptions of the actors; - Automated analysis of policies, SLAs and dependencies of different actors; - Optimisation of QoS policy decisions based on analysis of actor policy specifications. The business policies of the actors are related to the SLA rules, which restrictions are taken into consideration, when the user enters or changes his own QoS policies for the applications in the preferred network environment. Policy data mining for dynamic policy management includes related repositories (for business, intermediate and operational policies), based on which it is possible in dynamic manner to update QoS policy specifications of the users for given networks. This is required in case that SLAs or access rights (identity management policies) of the policy actors change. Provisioning of complex QoS policies for optimisation of QoS in heterogeneous Internet environment involves the interaction with learning component for usage and optimisation of heterogeneous networks, which are offered to the actors dependent on their SLAs. 3.2. Policy framework for heterogeneous network environment In the converged Internet infrastructures, there is a requirement to combine QoS policies with strategies for network selection for applications. QoS policies for heterogeneous networks are defined in order to set dynamically QoS requirements for applications for preferred networks dependent on the capabilities of selected networks and services. QoS policies for heterogeneous networks can be used for scenarios, including mobility and roaming, multiple path routing, change of network and traffic redirection. The QoS policy control for heterogeneous network environment can be based on user, application provider and operator centric policies. These policies can interact dependent on SLA and policy actor dependencies in order to control: - which QoS level of the application is specified for a given network; - which QoS and networks are preferred for the application execution. Wagner Expires April 2009 [Page 6] INTERNET-DRAFT Dynamic policy specification November 30, 2008 +-------------------------------+ | Application QoS Request of | | a policy actor | +-------------------------------+ | +------------------------------------------------------+ | | | | +-----------+ +-----------+ +-----------------+ +---------------------+ | Specific | | Global | | Optimal network | |Selection of network | | network | | selection | | selection | |with special purpose | | selection | | | | based on | |(DVB return channel, | | | | | | given criteria | | sensor, etc) | +-----------+ +-----------+ +-----------------+ +---------------------+ Figure 2: Actor's QoS policy requests for heterogeneous environment The QoS policy specification is based on network selection by the policy actors. In heterogeneous network environment, the policy actor can select: - QoS for specific network or set of networks, for which the application will be supported at the required QOS level; - Qos policy request considering all networks, which can be used by the policy actor (global selection); - QoS policy request for the application is applied for a dynamically selected network based on specific preference, such as cost efficiency, maximum resource availability. For the selected network, the QoS policy request for the application will be performed. - Selection of special purpose network means for instance selection of bidirectional wireless network for return channel emulation, or selection of network with specific capabilities (for instance sensor) for appropriate application. 3.3. Hierarchical policy mapping For automated QoS policy provisioning, the QoS policies are defined based on refinement in a hierarchical way considering abstraction levels: - Business (high-level or actor-oriented policies), - Intermediate QoS policies (unified policy presentations), - Operational (technology dependent QoS mechanisms of managed entities), - Configuration (vendor and system oriented QoS mechanisms of managed entities). The policy hierarchy for heterogeneous Internet environment deployed in NETQOS [1], [2] is shown in fig.3: Wagner Expires April 2009 [Page 7] INTERNET-DRAFT Dynamic policy specification November 30, 2008 Policy Hierarchy Policy specification +-----------------+ Actor related QoS request | Business policy | ............... for application on +-----------------+ preferred networks | related to SLA v +---------------------+ | Intermediate policy | ............. Unified QoS and network +---------------------+ requirement description | | for actors applications v v on given network context +-------------+ +-------------+ | Operational | | Operational | ..... QoS policy for concrete | policy | | policy | connections / flows +-------------+ +-------------+ | | v v +---------------+ +--------------+ .. Configuration policy | Configuration | |Configuration | for vendor specific QoS | policy | | policy | mechanisms +---------------+ +--------------+ at managed entities Figure 3: Hierarchical QoS policy refinement The QoS policies on business level are concise specifications of the QoS goals of the particular actors for preferred networks and are related to the SLA objectives. The business policies are transformed to the unified (intermediate) policy presentation. Intermediate policies are based on a unified presentation of QoS mechanisms and parameters using "condition and action" paradigm (see, RFC 3644) considering heterogeneous networks. The operational policies expressed in XACML (eXtensible Access Control Markup Language) [11] specify QoS mechanisms for control the treatment of the packets to/from the end-user for a specific flow dependent on the application class (content delivery, streaming, Voice over IP ) at concrete Internet infrastructure. The configuration policies are concrete descriptions for QoS of actor applications for heterogeneous entities at transport and network level, for instance CLI (Command Line Interface) batches of commands for the vendor dependent router QoS implementations (e.g. Cisco, Juniper or Linux). 4. Policy data mining The policy data mining is aimed at storage, mapping and access of QoS policies at different levels of refinement, in order to be used for dynamic QoS policy management. Wagner Expires April 2009 [Page 8] INTERNET-DRAFT Dynamic policy specification November 30, 2008 The policies are mapped between the different levels using policy repositories storing the policies and their relationships. There are business, intermediate and operational repositories, which are used for the tasks of QoS policy specification, policy decision and adaptation. The policy repositories have different roles based on their usage for different tasks for automated QoS management in heterogeneous Internet environment. In addition, there are knowledge and directory repositories, which are used by the policy data mining for SLA, network topology, actors and identity descriptions. The SLA rules specify generic requirements for the user policy mechanisms and parameters, such as network resource access permissions and QoS parameter thresholds. For the policy parameter specification and mapping between the parameters of policy repositories at different level, ontologies [12] and knowledge data bases are used. Ontology provides also the semantic mapping between the data in the policy repositories and knowledge data bases (e.g. directory services). +--------------------------------------> Links to Ontology, | | | directory services & | | | knowledge data bases +-----------+ +-----------+ +-----------+ | | Business |...| Business |...| Business | V | policy | | policy | | policy | +----------------+ | repository| | repository| | repository| | SLA, services | +-----------+ +-----------+ +-----------+ | ---------------| | | | | identity decsr| | | | +----------------+ | +------------------------+ | QoS policy | -----| Intermediate data base |------>| Ontology | +------------------------+ +----------------+ | +------------------------------------+ | | +------------------------+ +------------------------+ | operational/ | | operational/ | | configuration policies |...| configuration policies | | for managed entity | | for managed entity | +------------------------+ +------------------------+ Figure 4: Repositories and tasks for QoS policy management in heterogeneous Internet environment The policy management interfaces of the user stores the QoS policies in the business QoS policy repository. Usually, the business policy repositories are personalised and stored Wagner Expires April 2009 [Page 9] INTERNET-DRAFT Dynamic policy specification November 30, 2008 locally in respect to the actors, in order to be accessed efficiently by the policy management interfaces. The SLA rules, QoS policies on different level of refinement and identity specifications of actors are stored in appropriate data bases, which are accessed during the policy specification. This allows the consistency check of selected QoS requests and network environments for applications. Where the business policies can be stored locally for more efficient processing and integration with the actor oriented policy management interfaces, the intermediate policy repository is usually found on a policy server. This allows the intermediate policies to be accessed and maintained by the policy management system in a more efficient way. 5. Dynamic QoS policy specification and management in NETQOS system heterogeneous environment Dynamic QoS policy specification in NETQOS is actor and scenario based. The dynamic policy specification is implemented in NETQOS based on the following components: - Actor Preference Manager (APM) for actor and scenario oriented business level QoS policy specification; - Policy Description and Management (POLD) supporting unified policy access / storage for different QoS policy provisioning components. APM interfaces allows that different kinds of users, such as mobile and fixed users, dependent on their profile and dependencies store dynamically policies in the intermediate policy repository. Dependent on the QoS management goals of the actors, the SLAs and the particular scenario, the business level QoS policies for heterogeneous network environment allow selection of QoS parameters per applications for concrete network infrastructures (e.g. per network connection). The "on demand" user policy specification is restricted by the particular SLAs and dependencies of the actor's policies. To allow automated policy translation and consistency check, the policy information and related data are defined by ontologies [2], [12]. Ontology is used for policy specification and translation of business policies to intermediate, operation and configuration level specifications. The QoS policy management is based on translation of business policy specifications into unified policy repository. APM interfaces allow entering of policies by different actors and automated translation of dynamically specified requirements and preferences (e.g. business level policies) into intermediate (unified) policies. Wagner Expires April 2009 [Page 10] INTERNET-DRAFT Dynamic policy specification November 30, 2008 The common policy repository for unified (intermediate policies) supports: - Access to policies and check of their dependencies considering different actors (users, network operators and service providers), their dependencies and corresponding SLAs. - Interaction of the functions for automated policy provisioning using common and consistent policy definitions. POLD component includes functions for access, storage and update of intermediate policies. For automated QoS policy provisioning based on the intermediate policy repository the following components are interacting: - Automated Policy Adaptor (APA) for policy decision, enforcement and adaptation; - Monitoring and Measurement (MoMe) infrastructure for policy performance analysis and assessment of network QoS; - NetAgent and TransAgent for policy configuration at the managed entities, such as router or transport protocols, considering their particular capabilities; - Context Manager for control of interactions between different policy management components. The interactions of NETQOS components are shown in figure 5: Policy monitoring Management & assessment of of enforced policies interactions +--------+ +-------------+ | MoMe |<--------- | CM | +--------+ +-------------+ | | v v +------+ +-------+ +-------------+ Policy decision, +-------->| APM | --->| POLD |<---> | APA | adaptation, actor's +------+ +-------+ +-------------+ enforcement business | | | (operational QoS | | | policy) policies | | | interface Storage v Access | | +---------------------+ +------+ +----------+ | policy repository | | Net | | Transport| | (unified policies) | |Agent | | Agent | | policy translation | +------+ +----------+ +---------------------+ Configuration of operational policies at heterogeneous entities Figure 6: Interactions of NETQOS system components for dynamic QoS policy provisioning Wagner Expires April 2009 [Page 11] INTERNET-DRAFT Dynamic policy specification November 30, 2008 At the business level, QoS policies are entered dynamically by the actors using APM GUIs, which are designed considering the role, knowledge and expertise represented in ontology of the particular actors (operator, user, customer). The APM GUIs check the business level QoS requirements of the actors for consistency using using ontology and generate business level policy descriptions. For the automated provisioning, business level policies are translated (refined) into intermediate (unified) QoS policy abstractions and stored in the repository. The access to the policy repository is performed by the POLD component. POLD functions store the business policies of the actors as intermediate (unified) QoS policies in the repository. When the policy enforcement is required (launch of an actor's policy controlled application), the APA (Automated Policy Adaptor) component obtains the intermediate policies dealing with the application from the repository using POLD and transforms them into operational policies (represented as XACML messages). The operational policies are defined for managed entities and allow the mapping of the unified policy requirements to the specific QoS mechanisms of the managed heterogeneous entities (routers, services, protocols). The Transport and Network Agents, which are invoked by APA, receive the operational policies and enforcement instructions for automated configuration considering the specific capabilities of the transport and network entities. When the operational policy is enforced, the MoMe framework for evaluation of policy performance and detection of QoS degradation is automatically triggered. MoMe can detect specific events related to the policy (i.e. congestion, overloaded connection, etc.), and send signalling messages to the APA component which will adapt the operational QoS policies to meet the goals definde in the unified policies for this situation (application, service provider, network, ...). This way the NETQOS system supports dynamic QoS provisioning and adaptation for heterogeneous Internet environments based on dynamic QoS policy specifications by different actors, which take into account SLAs, ontology descriptions and expert knowledge. 6. References [1] EU IST project, Policy Based Management of Heterogeneous Networks for Guaranteed QoS (NETQOS), www.ist-netqos.org. [2] I. Miloucheva, D. Wagner, Ch. Niephaus, "User centric QoS policy management for heterogeneous Internet environment", ICT-Mobile Summit, Stockholm, Sweden, June, 2008. Wagner Expires April 2009 [Page 12] INTERNET-DRAFT Dynamic policy specification November 30, 2008 [3] P.A.Aranda Gutierrez, I. Miloucheva,Ch. Chassot, K. Drira, A. Flitzikowski, Ch. Brandauer, S. Romano, S. Rao, QoS policies for heterogeneous access network environment, draft-paag-qos-policy-00.txt, Internet Draft, Work in Progress, February 2007 [4] B. Moore, E. Elleson, J. Strassner, A. Westerinen, "Policy Core Information Model-Version 1 Specification", RFC 3060, Febr.2001. [5] B. Moore, Policy Core Information Model (PCIM) Extensions, RFC 3460, January 2003 [6] Y. Snir, Y. Ramberg, J. Strassner, R. Cohen, B. Moore, "Policy Quality of Service Information Model", RFC 3644, Nov. 2003. [7] B. Moore, D. Durham, J. Strassner, A. Westerinen, W. Weiss, "Information Model for Describing Network Device QoS Datapath Mechanisms", RFC 3670, January 2004. [8] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [9] A. Westerinen, J. Schnizlein, J. Strassner, M. Scherling, R. Quinn, S. Herzog, A. Huynh, M. Carlson, J. Perry, J. and M. Waldbusser, "Terminology for Policy-based Management", IETF RFC 3198, November 2001. [10] I. Miloucheva, D.Wagner, Ch. Niephaus, D. Hetzer, "User-centric identity enabled QoS policy management for Next Generation Internet", International Review on Computers and Software (IRECOS) Journal, July 2008. [11] OASIS eXtensible Access Control Markup Language (XACML) TC, XACML 2.0 Specification Set, XACML 3.0 Work in Progress. [12] OWL Web Ontology Language Semantics and Abstract Syntax, http://www.w3.org/TR/owl-features/ . 7. Author's Addresses David Wagner Fraunhofer Institute, SATCOM FOKUS,Schloss Birlinghoven 53757 Sankt Augustin, Germany Phone: +49-2241-14-3491 Email: david.wagner@fokus.fraunhofer.de Ilka Miloucheva Fraunhofer Institute, SATCOM FOKUS,Schloss Birlinghoven 53757 Sankt Augustin, Germany Phone: +49-2241-14-3471 Email: ilka.miloucheva@fokus.fraunhofer.de Wagner Expires April 2009 [Page 13] INTERNET-DRAFT Dynamic policy specification November 30, 2008 Christian Niephaus Fraunhofer Institute, SATCOM FOKUS,Schloss Birlinghoven 53757 Sankt Augustin, Germany Phone: +49-2241-14-3468 Email: christian.niephaus@fokus.fraunhofer.de Adam Flizikowski Adam Mickiewicz University (UAM) Department of Applied Informatics ul.Umultowska 85 61-614 Poznan, Poland Phone: +48-698-921-977 Email: adamf@amu.edu.pl Marcin Wachowiak ITTI sp. z o. o. ul. Rubiez 46C 61-612 Poznan, Poland Phone: +48-692-583-607 Email: marcin.wachowiak@itti.com.pl Pedro A. Aranda Gutierrez Telefinica I+D C/Emilio Vargas,6 E-28043 Madrid Phone: +34-913 374 702 Email: paag@tid.es Dirk Hetzer MEDIA BROADCAST GmbH Goslarer Ufer 35, D- 10589 Berlin Tel +49 30 3497 4600 Fax +49 391 5342650172 Email; dirk.hetzer@media-broadcast.com 8. Intellectual Property The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. Wagner Expires April 2009 [Page 14] INTERNET-DRAFT Dynamic policy specification November 30, 2008 The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. 9. Full Copyright Statement Copyright (C) The IETF Trust (2008). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Wagner Expires April 2009 [Page 15] INTERNET-DRAFT Dynamic policy specification November 30, 2008