Internet Research Task Force M. Behringer Internet-Draft M. Pritikin Intended status: Informational S. Bjarnason Expires: December 29, 2014 A. Clemm Cisco Systems B. Carpenter Univ. of Auckland S. Jiang Huawei Technologies Co., Ltd L. Ciavaglia Alcatel-Lucent June 27, 2014 Autonomic Networking - Definitions and Design Goals draft-irtf-nmrg-autonomic-network-definitions-01.txt Abstract Autonomic systems were first described in 2001. The fundamental goal is self-management, including self-configuration, self-optimization, self-healing and self-protection. This document applies the concepts of autonomic systems to a network, and describes the definitions and design goals of Autonomic Networking. The high-level goal for an autonomic function is to have minimal dependencies on human administrators or centralized management systems. This usually implies distribution across network elements. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on December 29, 2014. Behringer, et al. Expires December 29, 2014 [Page 1] Internet-Draft Autonomic Networking June 2014 Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction to Autonomic Networking . . . . . . . . . . . . 2 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Design Goals . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1. Self-Management . . . . . . . . . . . . . . . . . . . . . 4 3.2. By Default Secure . . . . . . . . . . . . . . . . . . . . 5 3.3. Decentralisation and Distribution . . . . . . . . . . . . 5 3.4. Simplification of the Northbound Interfaces . . . . . . . 5 3.5. Abstraction . . . . . . . . . . . . . . . . . . . . . . . 6 3.6. Autonomic Reporting . . . . . . . . . . . . . . . . . . . 6 3.7. Modularity . . . . . . . . . . . . . . . . . . . . . . . 6 3.8. Common Autonomic Networking Infrastructure . . . . . . . 7 3.9. Independence of Function and Layer . . . . . . . . . . . 7 3.10. Full Life Cycle Support . . . . . . . . . . . . . . . . . 8 4. Non Design Goals . . . . . . . . . . . . . . . . . . . . . . 8 4.1. Eliminate human operators . . . . . . . . . . . . . . . . 8 4.2. Eliminate emergency fixes . . . . . . . . . . . . . . . . 8 4.3. Eliminate management control and central policy . . . . . 9 4.4. Eliminate existing configuration tools . . . . . . . . . 9 4.5. Eliminate existing network management systems . . . . . . 9 5. An Autonomic Reference Model . . . . . . . . . . . . . . . . 9 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 8. Informative References . . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 1. Introduction to Autonomic Networking Autonomic systems were first described in a manifesto by IBM in 2001 [Kephart]. The fundamental concept involves eliminating external systems from a system's control loops and closing of control loops within the autonomic system itself, with the goal of providing the Behringer, et al. Expires December 29, 2014 [Page 2] Internet-Draft Autonomic Networking June 2014 autonomic system with self-management capabilities, including self- configuration, self-optimization, self-healing and self-protection. IP networking was initially designed with similar properties in mind. An IP network should be distributed and redundant to withstand outages in any part of the network. A routing protocol such as OSPF or ISIS exhibits properties of self-management, and can thus be considered autonomic in the definition of this document. However, as IP networking evolved, the ever increasing intelligence of network elements was often not put into protocols to follow this paradigm, but into configuration. This configuration made network elements highly dependent on some process that manages them, either a human, or a network management system. Autonomic Networking aims at putting the intelligence of today's operations back into algorithms at the node level, to minimize dependency on human administrators and central management systems. Some information an autonomic function requires however cannot be discovered; where input from some central intelligence is required, it is provided in a highly abstract, network wide form. This document provides the definitions and gesign goals for Autonomic Networking. 2. Definitions Autonomic: Self-managing (self-configuring, self-protecting, self- healing and self-optimizing); however, allowing high-level guidance by a central entity, through intent. Intent: An abstract, high level policy used to operate the network autonomically. Its scope is an autonomic domain, such as an enterprise network. It does not contain configuration or information for a specific node. It may contain information pertaining to nodes with a specific role. Autonomic Domain: A collection of autonomic nodes that instantiate the same intent. Autonomic Function: A feature or function which requires no configuration, and can derive all required information either through self-knowledge, discovery or through intent. Autonomic Service Agent: An agent implemented on an autonomic node which implements an autonomic function, either in part (in the case of a distributed function) or whole. Behringer, et al. Expires December 29, 2014 [Page 3] Internet-Draft Autonomic Networking June 2014 Autonomic Node: A node which employs autonomic functions. It may operate on any layer of the networking stack. Examples are routers, switches, personal computers, call managers, etc. Fully Autonomic Node: A node which employs exclusively autonomic functions. It requires no configuration. Autonomic Network: A network containing autonomic nodes. Fully Autonomic Network: A network consisting of exclusively fully autonomic nodes. 3. Design Goals This section explains the high level goals of Autonomic Networking, independent of any specific solutions. 3.1. Self-Management The original design goals of autonomic systems as described in [Kephart] also apply to Autonomic Networks. The over-arching goal is self-management, which is comprised of several self-* properties. The most commonly cited are: o Self-configuration: Functions do not require to be configured, but they configure themselves, based on self-knowledge, discovery, and intent. Discovery is the default way for an autonomic function to receive the information it needs to operate. o Self-healing: Autonomic functions adapt on their own to changes in the environment, and heal problems automatically. o Self-optimising: Autonomic functions automatically determine ways to optimise their behaviour. o Self-protection: Autonomic functions automatically secure themselves against potential attacks. Almost any network can be described as "self-managing", as long as the definition of "self" is large enough. For example, a well- defined SDN system, including the controller elements, can be described over all as "autonomic", if the controller provides an interface to the administrator which has the same properties as mentioned above (high level, network-wide, etc). For the work in the IETF and IRTF we define the "self" properties on the node level. It is the design goal to make functions on network nodes self- managing, in other words, minimally dependent on Behringer, et al. Expires December 29, 2014 [Page 4] Internet-Draft Autonomic Networking June 2014 management systems or controllers, as well as human operators. Self- managing functions on a node might need to exchange information with other nodes in order to achieve the required goals. 3.2. By Default Secure All autonomic interactions should be by default secure. This requires that any member of an autonomic domain can assert its membership using a domain identity, for example a certificate issued by a domain certification authority. This domain identity is used for nodes to learn about their neighbouring nodes, to determine the boundaries of the domain, and to cryptographically secure interactions within the domain. Nodes from different domains can also mutually verify their identity and secure interactions as long as they have a common trust anchor. A strong, cryptographically verifiable domain identity is a fundamental cornerstone in autonomic networking. It can be leveraged to secure all communications, and allows thus automatic security without traditional configuration, for example pre-shared keys. Autonomic functions must be able to adapt their behaviour depending on the domain of the node they are interacting with. 3.3. Decentralisation and Distribution The goal of Autonomic Networking is to minimise dependencies on central elements; therefore, de-centralisation and distribution are fundamental to the concept. If a problem can be solved in a distributed manner, it should not be centralised. In certain cases it is today operationally preferable to keep a central repository of information, for example a user database on a AAA server. An autonomic network must also be able to use such central systems, in order to be deployable. However, it is possible to distribute such databases as well, and such efforts should be at least considered. 3.4. Simplification of the Northbound Interfaces Even in a decentralised solution, certain information flows with central entities are required. Examples are the definition of intent or high level service definitions, as well as network status requests and aggregated reporting. Therefore, also elements in an autonomic network require a northbound interface. However, the design goal is to maintain this interface as simple and high level as possible. Behringer, et al. Expires December 29, 2014 [Page 5] Internet-Draft Autonomic Networking June 2014 3.5. Abstraction An administrator or autonomic management system interacts with an autonomic network on a high level of abstraction. Intent is defined at a level of abstraction that is much higher than that of typical configuration parameters, for example, "optimize my network for energy efficiency". Intent must not be used to convey low-level commands or concepts, since those are on a different abstraction level. The administrator should not even be exposed to the version of the IP protocol running in the network. Also on the reporting and feedback side an autonomic network abstracts information and provides high-level messages such as "the link between node X and Y is down". 3.6. Autonomic Reporting An autonomic network, while minimizing the need for user intervention, still needs to provide users with visibility like in traditional networks. However, in an autonomic network reporting should happen on a network wide basis. Information about the network should be collected and aggregated by the network itself, presented in consolidated fashion to the administrator. The layers of abstraction that are provided via intent need to be supported for reporting functions as well, in order to give users an indication about the effectiveness of their intent. For example, in order to assess how effective the network performs with regards to the intent "optimize my network for energy efficiency", the network should provide aggregate information about the number of ports that were able to be shut down while validating current service levels are on aggregate still met. Autonomic network events should concern the autonomic network as a whole, not individual systems in isolation. For example, the same failure symptom should not be reported from every system that observes it, but only once for the autonomic network as a whole. Ultimately, the autonomic network should support exception based management, in which only events that truly require user attention are actually notified. This requires capabilities that allow systems within the network to compare information and apply special algorithms to determine what should be reported. 3.7. Modularity It is unrealistic to expect a fully autonomic network in complex environments for many years to come. While simple networks may Behringer, et al. Expires December 29, 2014 [Page 6] Internet-Draft Autonomic Networking June 2014 become autonomic in one single step, a phased approach is required for most of today's networks. Autonomic functions can be implemented in a modular way. For example, the internal routing algorithm in many networks today is already mostly autonomic. Other modules can be made autonomic step by step. 3.8. Common Autonomic Networking Infrastructure [I-D.irtf-nmrg-an-gap-analysis] points out that there are already a number of fully or partially autonomic functions available today. However, they are largely independent, and each has its own methods and protocols to communicate, discover, define and distribute policy, etc. The goal of the work on autonomic networking in the IETF is therefore not just to create autonomic functions, but to define a common infrastructure that autonomic functions can use. This autonomic networking infrastructure may contain common control and management functions such as messaging, service discovery, negotiation, intent distribution, self-monitoring and diagnostics, etc. A common approach to define and manage intent is also required. Refer to the reference model below: All the components around the "autonomic service agents" should be common components, such that the autonomic service agents do not have to replicate common tasks individually. 3.9. Independence of Function and Layer Today's autonomic functions may reside on any layer in the networking stack. For example, layer 2 switching today is already relatively autonomic in many environments; routing functions can be autonomic. "Autonomic" in the context of this framework is a property of a function on a node. This node can be a switch, router, server, or call manager. Autonomic functionality is independent of the function of a node. Even application layer functionality such as unified communications can be autonomic. An Autonomic Network requires an overall control plane for autonomic nodes to communicate. As in general IP networking, IP is the layer that binds all those elements together; autonomic functions in the context of this framework should therefore operate at the IP layer. This concerns neighbour discovery protocols and other autonomic control plane functions. Behringer, et al. Expires December 29, 2014 [Page 7] Internet-Draft Autonomic Networking June 2014 3.10. Full Life Cycle Support An autonomic function does not depend on external input to operate; it needs to understand its current situation and surrounding, and operate according to its current state. Therefore, an autonomic function must understand the full life cycle of the device it runs on, from first manufacturing testing through deployment, testing, troubleshooting, up to decommissioning. The state of the life-cycle of an autonomic node is reflected in a state model. The behaviour of an autonomic function may be different for different deployment states. 4. Non Design Goals This section identifies various items which are explicitly not design goals for autonomic networks, which are mentioned to avoid misunderstandings of the general intention. 4.1. Eliminate human operators The problem targeted by autonomic networking is the error-prone and hard to scale model of individual configuration of network elements, traditionally by manual commands but today mainly by scripting and/or configuration management databases. This does not, however, imply the elimination of skilled human operators, who will still be needed for oversight, policy management, diagnosis, reaction to help desk tickets, etc. etc. The main impact on operators should be less tedious detailed work and more high-level work. (They should become more like doctors than hospital orderlies.) 4.2. Eliminate emergency fixes However good the autonomous mechanisms, sometimes there will be fault conditions etc. that they cannot deal with correctly. At this point skilled operator interventions will be needed to correct or work around the problem. Hopefully this can be done by high-level mechanisms (adapting the policy database in some way) but in some cases direct intervention at device level may be unavoidable. This is obviously the case for hardware failures, even if the autonomic network has bypassed the fault for the time being. Truck rolls will not be eliminated when faulty equipment needs to be replaced. However, this may be less urgent if the autonomic system automatically reconfigures to minimise the operational impact. Behringer, et al. Expires December 29, 2014 [Page 8] Internet-Draft Autonomic Networking June 2014 4.3. Eliminate management control and central policy Senior management might fear loss of control of an autonomic network. In fact this is no more likely than with a traditional network; the emphasis on automatically applying general policy and security rules might even provide more management control. 4.4. Eliminate existing configuration tools While autonomic networks will rarely need manual intervention, there is no expectation that traditional top-down configuration tools will vanish immediately. Autonomic techniques will have to co-exist with them, and they will survive for as long as they are useful. Initially they will certainly play a part in confidence-building in the autonomic method, and they will be held in reserve for emergency use for a long time. 4.5. Eliminate existing network management systems Existing monitoring and reporting systems will continue to be needed, and as just noted existing configuration mechanisms will not vanish. Therefore, it is to be expected that the existing NMS will be retained in parallel with autonomic mechanisms, and will be adapted as necessary. Some aspects of the autonomic mechanism (e.g. aggregated reporting, exception reporting) should indeed be integrated with the existing NMS as far as possible. 5. An Autonomic Reference Model An Autonomic Network consists of Autonomic Nodes. Those nodes communicate with each other through an Autonomic Control Plane which provides a robust and secure communications overlay. The Autonomic Control Plane is self-organizing and autonomic itself. An Autonomic Node contains various elements, such as autonomic service agents which immplement autonomic functions. Figure 1 shows a reference model of an autonomic node. The elements and their interaction are: o Autonomic Service Agents, which implement the autonomic behaviour of a specific service or function. o Self-knowledge: An autonomic node knows its own properties and capabilities o Network Knowledge (Discovery): An autonomic service agent may require various discovery functions in the network, such as service discovery. Behringer, et al. Expires December 29, 2014 [Page 9] Internet-Draft Autonomic Networking June 2014 o Intent: Network wide high level policy. Autonomic Service Agents use an intent interpretation engine to locally instantiate the global intent. This may involve coordination with other Autonomic Nodes. o Feedback Loops: Control elements outside the node may interact with autonomic nodes through feedback loops. o An Autonomic User Agent, providing a front-end to external users (administrators and management applications) through which they can communicate intent, receive reports, and monitor the Autonomic Network. o Autonomic Control Plane: Allows the node to communicate with other autonomic nodes. Autonomic functions such as intent distribution, feedback loops, discovery mechanisms, etc, use the autonomic control plane. Behringer, et al. Expires December 29, 2014 [Page 10] Internet-Draft Autonomic Networking June 2014 +------------------------------------------------------------+ | +----------+ +--------------+ | | | | | Feedback | | | | Intent | | Loops | | | +----------+ +--------------+ | | ^ ^ | | Autonomic User Agent | | V V | | +-----------+ +------------+ +------------+ | | | Self- | | Autonomic | | Network | | | | knowledge |<------>| Service |<------>| Knowledge | | | | | | Agents | | (Discovery)| | | +-----------+ +------------+ +------------+ | | ^ ^ | | | | | | V V | |------------------------------------------------------------| | Autonomic Control Plane | |------------------------------------------------------------| | Standard Operating System Functions | +------------------------------------------------------------+ Figure 1 6. Security Considerations This document provides definitions and design goals for autonomic networking. A full threat analysis will be required as part of the development of solutions, taking account of potential attacks from within the network as well as from outside. 7. Acknowledgements The work on Autonomic Networking is the result of a large team project at Cisco Systems. In alphabetical order: Ignas Bagdonas, Parag Bhide, Balaji BL, Toerless Eckert, Yves Hertoghs, Bruno Klauser. The ETSI working group AFI (http://portal.etsi.org/afi) defines a similar framework for autonomic networking in the "General Autonomic Network Architecture" [GANA]. Many concepts explained in this document can be mapped to the GANA framework. The mapping is outside the scope of this document. Special thanks to Ranganai Chaparadza for his comments and help on this document. Behringer, et al. Expires December 29, 2014 [Page 11] Internet-Draft Autonomic Networking June 2014 8. Informative References [GANA] ETSI GS AFI 002, , "Autonomic network engineering for the self-managing Future Internet (AFI): GANA Architectural Reference Model for Autonomic Networking, Cognitive Networking and Self-Management.", April 2013, . [I-D.irtf-nmrg-an-gap-analysis] Behringer, M., Carpenter, B., and S. Jiang, "Gap Analysis for Autonomic Networking", draft-irtf-nmrg-an-gap- analysis-00 (work in progress), April 2014. [Kephart] Kephart, J. and D. Chess, "The Vision of Autonomic Computing", IEEE Computer vol. 36, no. 1, pp. 41-50, January 2003. Authors' Addresses Michael Behringer Cisco Systems Building D, 45 Allee des Ormes Mougins 06250 France Email: mbehring@cisco.com Max Pritikin Cisco Systems Email: pritikin@cisco.com Steinthor Bjarnason Cisco Systems Email: sbjarnas@cisco.com Alex Clemm Cisco Systems Email: alex@cisco.com Behringer, et al. Expires December 29, 2014 [Page 12] Internet-Draft Autonomic Networking June 2014 Brian Carpenter Department of Computer Science University of Auckland PB 92019 Auckland 1142 New Zealand Email: brian.e.carpenter@gmail.com Sheng Jiang Huawei Technologies Co., Ltd Q14, Huawei Campus No.156 Beiqing Road Hai-Dian District, Beijing 100095 P.R. China Email: jiangsheng@huawei.com Laurent Ciavaglia Alcatel-Lucent Email: Laurent.Ciavaglia@alcatel-lucent.com Behringer, et al. Expires December 29, 2014 [Page 13]