Network Working Group T. Dreibholz Internet-Draft University of Duisburg-Essen Intended status: Informational L. Coene Expires: January 12, 2009 Nokia Siemens Networks P. Conrad University of Delaware July 11, 2008 Reliable Server Pooling Applicability for IP Flow Information Exchange draft-coene-rserpool-applic-ipfix-06.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 January 12, 2009. Dreibholz, et al. Expires January 12, 2009 [Page 1] Internet-Draft RSerPool Applicability for IPFIX July 2008 Abstract This document describes the applicability of the Reliable Server Pooling architecture to the IP Flow Information Exchange using the Aggregate Server Access Protocol (ASAP) functionality of RSerPool only. Data exchange in IPFIX between the router and the data collector can be provided by a limited retransmission protocol. Dreibholz, et al. Expires January 12, 2009 [Page 2] Internet-Draft RSerPool Applicability for IPFIX July 2008 1. Introduction Reliable Server Pooling provides protocols for providing highly available services. The services are located in a pool of redundant servers and if a server fails, another server will take over. The only requirement put on these servers belonging to the pool is that if state is maintained by the server, this state must be transferred to the other server taking over. The goal is to provide server-based redundancy. Transport and network level redundancy are handle by the transport and network layer protcols. The application may choose to distribute its traffic over the servers of the pool conforming to a certain policy. The application wishing to make use of RSerPool protocols may use different transport layers (such as UDP, TCP and SCTP). However, some transport layers may have restrictions build in in the way they might be operating in the RSerPool architecture and its protocols. 1.1. Scope The scope of this document is to explain the way that a minimal version of Reliable Server Pooling protocols have to be used in order to provide a highly available service towards IP Flow Information Exchange (IPFIX) protocols. 1.2. Terminology The terms are commonly identified in related work and can be found in the Aggregate Server Access Protocol and Endpoint Handlespace Redundancy Protocol Common Parameters document ietf-rserpool-common- param [I-D.ietf-rserpool-common-param] Dreibholz, et al. Expires January 12, 2009 [Page 3] Internet-Draft RSerPool Applicability for IPFIX July 2008 2. IPFIX using RSerPool 2.1. Architecture IP flow information is exchanged between observation points and collector points. The observation points may try to find out via the Aggregate Server Access Protocol (ASAP, see ietf-rserpool-asap [I-D.ietf-rserpool-asap]) which collector point(s) are active. Both the observation and the collector point may have limitations for exchanging the information (observation point may have limited buffer space and collectors points may be overburdened with receiving lots of flow information from different observation points). The observation point will query the ENRP server for resolution of a particular collector pool name and the ENRP server will return a list of one or more collector points to the observation point. The observation point will use its own transport protocols (TCP, UDP, SCTP, SCTP with PR-SCTP extension) for exchanging the IPFIX data between the observation point and the collector point. If a collector point would fail, then the observation point will send its data towards a different collector point, belonging to the same collector pool. Collector points will announce themselves to the ENRP server and will be monitored for their availability. The observation point will only query the ENRP server for server pool name resolution. Dreibholz, et al. Expires January 12, 2009 [Page 4] Internet-Draft RSerPool Applicability for IPFIX July 2008 3. Transport protocols suitable for IPFIX The exchange of IP flow information data between an observation point and a collection point consists of massive amounts of data. One collection point can service many observation points, therefore transport protocols must do congestion control (example: modifying the receive buffer space, thus reducing the incoming flow of data), so that the collection point is not overburdened by its observation points. Some data must arrive at the collector while other data might arrive (if it gets lost: no problem). The choice of reliable or partial reliable delivery has to be made by the observation point These requirements demand a protocol which provides variable transport reliability of its data: it should be able to chose the reliability by the IPFIX protocols on a a per-message base. SCTP with PR-SCTP extension is the only know protocol which allows the choice of full, partial or unreliable delivery of the message to its peer node. TCP will only allow fully reliable delivery, while UDP only provides unreliable delivery and NO congestion control. Dreibholz, et al. Expires January 12, 2009 [Page 5] Internet-Draft RSerPool Applicability for IPFIX July 2008 4. Security considerations The protocols used in the Reliable Server Pooling architecture only try to increase the availability of the servers in the network. RSerPool protocols do not contain any protocol mechanisms which are directly related to user message authentication, integrity and confidentiality functions. For such features, it depends on the IPSEC protocols or on Transport Layer Security (TLS) protocols for its own security and on the architecture and/or security features of its user protocols. The RSerPool architecture allows the use of different transport protocols for its application and control data exchange. These transport protocols may have mechanisms for reducing the risk of blind denial-of-service attacks and/or masquerade attacks. If such measures are required by the applications, then it is advised to check the SCTP applicability statement RFC2057 [RFC3257] for guidance on this issue. Dreibholz, et al. Expires January 12, 2009 [Page 6] Internet-Draft RSerPool Applicability for IPFIX July 2008 5. Acknowledgments The authors wish to thank Maureen Stillman and many others for their invaluable comments. Dreibholz, et al. Expires January 12, 2009 [Page 7] Internet-Draft RSerPool Applicability for IPFIX July 2008 6. References 6.1. Normative References [RFC3237] Tuexen, M., Xie, Q., Stewart, R., Shore, M., Ong, L., Loughney, J., and M. Stillman, "Requirements for Reliable Server Pooling", RFC 3237, January 2002. [RFC3668] Bradner, S., "Intellectual Property Rights in IETF Technology", RFC 3668, February 2004. [I-D.ietf-rserpool-arch] Tuexen, M., "Architecture for Reliable Server Pooling", draft-ietf-rserpool-arch-12 (work in progress), November 2006. [I-D.ietf-rserpool-asap] Stewart, R., Xie, Q., Stillman, M., and M. Tuexen, "Aggregate Server Access Protocol (ASAP)", draft-ietf-rserpool-asap-20 (work in progress), May 2008. [I-D.ietf-rserpool-enrp] Xie, Q., Stewart, R., Stillman, M., Tuexen, M., and A. Silverton, "Endpoint Handlespace Redundancy Protocol (ENRP)", draft-ietf-rserpool-enrp-20 (work in progress), May 2008. [I-D.ietf-rserpool-common-param] Stewart, R., Xie, Q., Stillman, M., and M. Tuexen, "Aggregate Server Access Protocol (ASAP) and Endpoint Handlespace Redundancy Protocol (ENRP) Parameters", draft-ietf-rserpool-common-param-17 (work in progress), May 2008. [RFC2960] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer, H., Taylor, T., Rytina, I., Kalla, M., Zhang, L., and V. Paxson, "Stream Control Transmission Protocol", RFC 2960, October 2000. [RFC3758] Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P. Conrad, "Stream Control Transmission Protocol (SCTP) Partial Reliability Extension", RFC 3758, May 2004. [RFC3257] Coene, L., "Stream Control Transmission Protocol Applicability Statement", RFC 3257, April 2002. [I-D.ietf-rserpool-service] Conrad, P. and P. Lei, "Services Provided By Reliable Dreibholz, et al. Expires January 12, 2009 [Page 8] Internet-Draft RSerPool Applicability for IPFIX July 2008 Server Pooling", draft-ietf-rserpool-service-02 (work in progress), October 2005. 6.2. Informative References [RSerPoolPage] Dreibholz, T., "Thomas Dreibholz's RSerPool Page", URL: http://tdrwww.exp-math.uni-essen.de/dreibholz/rserpool/. [Dre2006] Dreibholz, T., "Reliable Server Pooling -- Evaluation, Optimization and Extension of a Novel IETF Architecture", Ph.D. Thesis University of Duisburg-Essen, Faculty of Economics, Institute for Computer Science and Business Information Systems, URL: http:// duepublico.uni-duisburg-essen.de/servlets/DerivateServlet/ Derivate-16326/Dre2006-final.pdf, March 2007. Dreibholz, et al. Expires January 12, 2009 [Page 9] Internet-Draft RSerPool Applicability for IPFIX July 2008 Authors' Addresses Thomas Dreibholz University of Duisburg-Essen, Institute for Experimental Mathematics Ellernstrasse 29 45326 Essen, Nordrhein-Westfalen Germany Phone: +49-201-1837637 Fax: +49-201-1837673 Email: dreibh@iem.uni-due.de URI: http://www.iem.uni-due.de/~dreibh/ Lode Coene Nokia Siemens Networks Atealaan 32 Herentals 2200 Belgium Phone: +32-14-252081 Email: lode.coene@nsn.com Phillip Conrad University of Delaware 103 Smith Hall Newark DE 19716 USA Phone: +1 302 831 8622 Email: conrad@acm.org Dreibholz, et al. Expires January 12, 2009 [Page 10] Internet-Draft RSerPool Applicability for IPFIX July 2008 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. 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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. 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. Dreibholz, et al. Expires January 12, 2009 [Page 11]