IPFIX Working Group A. Kobayashi, Ed. Internet-Draft NTT PF Lab. Intended status: Informational May 13, 2008 Expires: November 14, 2008 IPFIX Mediation: Problem Statement draft-ietf-ipfix-mediators-problem-statement-00 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 November 1, 2008. Kobayashi, et al. Expires November 1, 2008 [Page 1] Internet-Draft Mediation Problem Statement April 2008 Abstract Flow-based measurement is currently a popular method for traffic monitoring. To construct a measurement system, an IPFIX mediation device (IPFIX Mediator), which reroutes, filters, aggregates, or modifies Flow information, may help scalability and several other purposes. This document describes the applicability of an IPFIX Mediator and the problems that the IPFIX Mediator might encounter. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Flow-Based Mediation Devices: Examples of Applicability . . . 6 3.1. Inter-domain IPFIX Exporting . . . . . . . . . . . . . . . 6 3.2. Data Retention . . . . . . . . . . . . . . . . . . . . . . 6 3.3. Interoperability between Legacy Protocols and IPFIX . . . 6 3.4. Flow Distribution to Specific Collectors . . . . . . . . . 7 3.5. Aggregation and Harmonization of Metering Process Rules . 7 4. Approaches to Scalability . . . . . . . . . . . . . . . . . . 8 4.1. Adjusting Sampling Rates . . . . . . . . . . . . . . . . . 8 4.2. Exporting Aggregated Flows from Original Exporters . . . . 9 4.3. Hierarchical Model of Flow Aggregation . . . . . . . . . . 9 4.4. Flow-Based Collector Selection . . . . . . . . . . . . . . 9 4.5. Flow Selection Sampling . . . . . . . . . . . . . . . . . 10 4.6. Information Elements and Flow Keys Selection . . . . . . . 11 5. Problems with using IPFIX Mediators . . . . . . . . . . . . . 12 5.1. Loss of Observation Point Information . . . . . . . . . . 12 5.2. Loss of Base Time Information . . . . . . . . . . . . . . 13 5.3. Loss of Option Template Information . . . . . . . . . . . 13 5.4. Observation Domain ID and Template ID Management . . . . . 14 5.5. Transport Sessions Management . . . . . . . . . . . . . . 14 6. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . 15 7. Security Considerations . . . . . . . . . . . . . . . . . . . 17 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19 9.1. Normative References . . . . . . . . . . . . . . . . . . . 19 9.2. Informative References . . . . . . . . . . . . . . . . . . 19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20 Intellectual Property and Copyright Statements . . . . . . . . . . 22 Kobayashi, et al. Expires November 1, 2008 [Page 2] Internet-Draft Mediation Problem Statement April 2008 1. Introduction While the requirements for IPFIX defined in [RFC3917] mention an intermediate device between Exporters and Collectors, such as an IPFIX Proxy or an Concentrator, there is no document to define this intermediate device, termed IPFIX Mediator. This document presents several application examples, problems and weak points regarding the specification of IPFIX Mediators. In section 2, the terminologies and concepts used in this document are presented. In section 3, several application examples of IPFIX Mediators are listed. Especially, the more effective usage in large- scale networks is presented in section 4. It describes the approaches to scalability of a flow-based measurement system and some solutions regarding IPFIX Mediators. Finally, section 5 describes the issues regarding the implementation of an IPFIX Mediator. Kobayashi, et al. Expires November 1, 2008 [Page 3] Internet-Draft Mediation Problem Statement April 2008 2. Terminology The terminology used in this document is fully aligned with that defined in [RFC5101]. Other terms related to IPFIX Mediation are defined here. All these terms are capitalized in this document. IPFIX Mediator An IPFIX Mediator is a device that routes Flow Records or changes the Flow Records information. It hosts at least one Collecting Process and one Exporting Process. An IPFIX Mediator is formally defined to consist of one or more Collecting Processes, zero or more intermediate processes and one or more Exporting Processes. Figure A shows the relationship among these processes. .-------------------------------------------------. | .----------. .----------.| | .----------.| .------------. .----------.|| |.----------.|| .------------.| .----------.||| IPFIX ||Collecting||| |Intermediate|| |Exporting ||||IPFIX ----->||Processes ||'-->|Proceses ||-->|Processes ||'|-----> || |' |(optional) |' | |' | |'----------' '------------' '----------' | '-------------------------------------------------' Figure A: Basic IPFIX Mediator Model. Basically, IPFIX Mediators have two types of mediation functions, as follows. * IPFIX Protocol Mediation This type of IPFIX Mediator forwards input Flow Records to Collectors. IPFIX Protocol Mediation does not change information, but simply relays the Flow Records from receiving IPFIX Transport Sessions to exporting IPFIX Transport Sessions. Examples are an IPFIX Proxy and an IPFIX protocol converter, both described in [RFC3917], as well as an IPFIX Distributor. * IPFIX Flow Mediation This type of IPFIX Mediator creates new sets of Flow Records from input Flow Records. The Flow Mediation consists of a set of functions that include Flow aggregation, selection, or modification. The modification of Flow Records includes changing the value of specified Information Elements, or changing the Template and record structure. Examples are an Kobayashi, et al. Expires November 1, 2008 [Page 4] Internet-Draft Mediation Problem Statement April 2008 IPFIX Concentrator, which are described in [RFC3917], and an IPFIX Masquerading Proxy. Being a stand-alone device is not necessary, as these functions can be included in the Exporter, such as router or switch. Original Exporter An Original Exporter is an Exporter which hosts Observation Points where IP packets can be directly observed, as opposed to an IPFIX Mediator, which hosts an Exporting Process, but doesn't have any Observation Point. IPFIX Proxy An IPFIX Proxy acts as a proxy for an Original Exporter, which hosts Observation Points. It may receive Flow Records and send them to one or multiple Collectors. IPFIX Concentrator An IPFIX Concentrator receives Flow Records, aggregates them, then exports the aggregated Flow Records. IPFIX Distributor An IPFIX Distributor classifies the input Flow Records based on their contents. Depending on their classification, such as IPv4 and IPv6, it exports them to one or more of several different Collectors, replicating input Flow Records, if necessary. IPFIX Masquerading Proxy An IPFIX Masquerading Proxy screens out a part of data of input Flow Records according to configured policies. It can thus, for example, hide the network topology information or customers' IP addresses. Kobayashi, et al. Expires November 1, 2008 [Page 5] Internet-Draft Mediation Problem Statement April 2008 3. Flow-Based Mediation Devices: Examples of Applicability 3.1. Inter-domain IPFIX Exporting Inter-domain IPFIX Exporting can be used to measure traffic for wide- area traffic engineering, or to analyze the behavior of Internet traffic. In cases like this, network operators need to adhere to privacy policies and prevent from spreading confidential information. Using an IPFIX Masquerading Proxy allows them to operate on Flow Records safely by anonymizing and filtering them. 3.2. Data Retention Data retention refers to the storage of data records by service providers and commercial organizations. According the European Commission directives, service providers are required to retain both IP and voice traffic data, in wireline and wireless networks, generated by end users while using SPs services. The goal of data retention is to ensure that call detail records and flow records are available if necessary for the purpose of detection, investigation, and prosecution of serious crimes. The European Commission directives define the following data retention services: o Fixed telephony (includes fixed voice, voicemail, and conference and data calls) o Mobile telephony (includes mobile voice, voicemail, conference and data calls, SMS, and MMS) o Internet telephony (includes every multimedia session associated with IP multimedia services) o Internet e-mail o Internet access By monitoring Flow Records, IPFIX can fulfill these requirement of Internet access services. 3.3. Interoperability between Legacy Protocols and IPFIX During the migration process from legacy protocols such as NetFlow [RFC3954] to IPFIX, both NetFlow and IPFIX Exporters will need to co- exist in the same network. An IPFIX Mediator which converts a legacy protocol to IPFIX will allow operators to continue measuring Flows from legacy Exporters, even after introducing IPFIX Collectors. Kobayashi, et al. Expires November 1, 2008 [Page 6] Internet-Draft Mediation Problem Statement April 2008 3.4. Flow Distribution to Specific Collectors Recently, several networks seem to have shifted towards Integrated Networks, such as the Internet and MPLS, which includes IPv4, IPv6, and VPN traffic. Flow Records of these types need to be analyzed separately and from different perspectives. However, handling them separately without improving the capability of the Collector is difficult. If the Original Exporter can not classify specific Flow Records based on their contents and distribute them, the Collector has to be able to handle all kinds of unclassified Flow Records. Aside from the Original Exporter, IPFIX Distributors assisting Flow distribution would be necessary. Each individual Collector can analyze the distributed Flow Records based on the nature of each network. 3.5. Aggregation and Harmonization of Metering Process Rules Because of a Collector's performance limit, adjusting metering process rules, such as sampling rate, the active/inactive timeout, and the Flow Key [RFC5101], is necessary. Also, IPFIX Concentrators could adjust the load of the measurement system by aggregating input Flow Records within a given time interval. By changing the Flow Key and time outs, the granularity of the Flows increases, and the number of Flow Records decreases. This function is especially important in large scale networks, which require scalable measurement systems. Kobayashi, et al. Expires November 1, 2008 [Page 7] Internet-Draft Mediation Problem Statement April 2008 4. Approaches to Scalability Usually, network operators measure traffic at several Observation Points for a specific purpose, typically sampling packets with rates ranging from 1/10,000 to 1/100. This value depends on several factors, such as the capacity of the management network, the available storage and speed of the Collector, and the load on the routers/switches. Currently, network providers extensively use flow-based measurements. The number of Observation Points in the networks can even be increased to improve the effectiveness of these methods. In the near future, we anticipate that the advanced features of IPFIX, such as the monitoring of wide-area traffic matrices and QoS performance, will accelerate IPFIX utilization. On the other hand, the increasing amount of traffic brought about by broadband users might have an impact on measurement parameters, such as the sampling rate or granularity of Flows. Generally, large-scale networks already have multiple 10 Gb/s links, their total traffic exceeding 100 Gb/s. In the near future, broadband users' traffic will increase by approximately 50% per year according to [TRAFGRW]. When operators monitor traffic of 500 Gb/s with a sampling rate of 1/1000, the amount of exported Flow Records from Exporters could exceed 50 kFlows/s. This value is beyond the ability of a single Collector. It should be noted that the current sampling rate might become infeasible for Exporters within the next five years. To avert this, network operators can consider several solutions. This section explains how operators can cope with such a huge amount of Flow Records using available IPFIX solutions. 4.1. Adjusting Sampling Rates Adjusting the sampling rate reduces the amount of Flow Records, and a flow-based measurement system can thus easily adapt to the ability of the Collecting and Exporting Processes. However, in that case, Flows with small traffic volumes could easily get lost. If traffic incidents happened, network operators would no longer be able to investigate traffic behavior. While traffic volumes on networks continue to increase, network operators will not be able to maintain the sampling rates currently used. In the near future, flow-based measurement systems possibly will not be able to detect traffic anomalies which can currently be detected. Kobayashi, et al. Expires November 1, 2008 [Page 8] Internet-Draft Mediation Problem Statement April 2008 4.2. Exporting Aggregated Flows from Original Exporters The simplest types of Flows are those comprised of all packets having a fixed five tuple of protocol, source and destination IP addresses, and source and destination port numbers. On the other hand, choosing a shorter Flow Key, such as a three tuple or two tuple, or a single Flow Key, such as a network prefix, peering AS number, or BGP Next- Hop, creates more aggregated Flow Records. This solution is especially useful for measurements of traffic exchange in an entire network domain and for easy adjustments to the performance of a Collector. However, in-depth monitoring of traffic behavior is no longer possible, as it is with the five tuple. Another approach involves the router, which has several different caches. Each cache is optimized for a specific application, so it has its own series of Flow Keys and its contents are sent to a specific Collector. There is a Collector for security, another for capacity planning, and so on. The content and granularity of the Flow satisfies the requirements of each Collector. 4.3. Hierarchical Model of Flow Aggregation In large-scale networks, creating a hierarchical aggregation system by using IPFIX Concentrators can prove to be very useful. Collecting the aggregated Flow Records exported by IPFIX Concentrators from whole networks enables measuring of the traffic behavior of entire networks. In addition, if IPFIX Concentrators store the received Flow Records, and then the stored Flow Records are allowed to be retrieved by other devices, this architecture might actually become a most useful distributed-collection system. As described in [I-D.dressler-ipfix-aggregation], in the case of a measurement system consisting of both aggregating and non-aggregating Exporters, an IPFIX Concentrator can assist the latter by aggregating received Flow Records to any granularity. 4.4. Flow-Based Collector Selection In general, a distributive system allows the work of the Collectors to be divided. Classifying Flow Records based on the value of specified Information Elements can prove to be very useful for achieving scalability. In the simplest case, Original Exporters export all Flow Records without requiring any additional functions. An IPFIX Distributor classifies Flow Records based on the value of specified Information Elements and exports the classified Flow Records to individual Collectors. This is called Flow-Based Collector Selection. In particular, in an integrated network situation, the nature of each Kobayashi, et al. Expires November 1, 2008 [Page 9] Internet-Draft Mediation Problem Statement April 2008 network is different, although several kinds of networks, such as VPNs and the Internet, share a physical network. This function allows individual Collectors related to each network to analyze traffic behavior for their own specific purposes. An IPFIX Distributor could, for example, distribute Flow Records based on the value of RD (Route Distinguisher), ingress IF, peering AS number, or BGP next hop, all of which identify the customer. As shown in the following figure, the IPFIX Distributor distributes Flow Records based on RD. This system allows each customer's traffic to be inspected independently. .---------. |Traffic | .---->|Collector|<==>Customer#A | |#1 | | '---------' RD=100:1 .-----------. | .--------. |IPFIX |----' .---------. |IPFIX | |Distributor| RD=100:2 |Traffic | |router#1|------->| |--------->|Collector|<==>Customer#B | | | | |#2 | '--------' | |----. '---------' '-----------' | RD=100:3 | .---------. | |Traffic | '---->|Collector|<==>Customer#C |#3 | '---------' Figure B: Flow-Based Collector Selection. There currently is no description of a flow-based collector selection function in IPFIX. In the current implementation, many Exporters send all Flow Records to multiple Collectors and those Collectors drop uninteresting Flow Records to reduce their load. This wastes network resources. 4.5. Flow Selection Sampling The Flow selection sampling method is described in [I-D.peluso-flowselection] in detail. Generally, the distribution of the number of packets per Flow seems to be heavy-tailed. Most types of Flow Records are likely to be small Flows consisting of a small number of packets. The flow-based measurement system, in particular the Collecting Process and Exporting Process, is burdened with a huge Kobayashi, et al. Expires November 1, 2008 [Page 10] Internet-Draft Mediation Problem Statement April 2008 number of these small Flows. If statistics information of small Flows is exported as merging data by applying a policy or threshold, the burden on measurement system is reduced. In addition, if this function is in the IPFIX Mediator, it is beneficial for enhancing the scalability. 4.6. Information Elements and Flow Keys Selection Originally, the Flow Keys [RFC5101] on the routers were defined by a fixed seven tuple of packet fields. However, one way to scale the system is to be able to specify the Template Records for specific needs. This extra flexibility in the Metering Process allows administrators to specify their own set of Flow Keys and extra Information Elements in the Template Record. On one hand, this optimizes the Metering Process, because only Flows of interest are looked at. On the other hand, it optimizes the Exporting Process, because only the information of interest is exported. Finally, this reduces load of the Collecting Process as less Flow Records are handled, and Flow Record filtering and aggregating are required. Kobayashi, et al. Expires November 1, 2008 [Page 11] Internet-Draft Mediation Problem Statement April 2008 5. Problems with using IPFIX Mediators As described in the previous section, less demanding sampling rates make small flows invisible, while aggregated Flow Records make elements, e.g. port numbers or IP addresses, invisible. Even if traffic grows, network operators would like to maintain the same sampling rate and granularity of flows as much as possible. A hierarchical structure and flow-based Collector selection are useful for creating a scalable collection system. These solutions can be implemented by using IPFIX Mediators, such as IPFIX Concentrators and IPFIX Distributors. In this section, we focus on the problems related to the use of IPFIX Mediators. 5.1. Loss of Observation Point Information Both the Exporter IP address indicated by the source IP address of the IPFIX session as well as the Observation Domain ID included in the IPFIX header are likely to be lost in the mediation process performed by an IPFIX Mediator. This IP address and Observation Domain ID indicate the Observation Point information from the viewpoint of the entire network domain. Such information is necessary for guaranteeing the continuity of the work of the top level Collector. Even if an IPFIX Mediator could, with some new mechanism, notify Collectors of this Observation Point information, older Collectors might not accept it. These Collectors would then wrongly assume that the IP address of the IPFIX Mediator is that of the Original Exporter. The Collector, however, needs to recognize the precise Observation Point whether Flow Records go through an IPFIX Mediator or not. Kobayashi, et al. Expires November 1, 2008 [Page 12] Internet-Draft Mediation Problem Statement April 2008 In the following figure, a Collector could identify 2 Exporters with IP addresses of 10.1.1.3 and 10.1.1.2, respectively. The Collector, however, needs to somehow recognize Router#1 and Router#2, which are the Original Exporters. Defined notification methods that can be interpreted by Collectors and Mediators are thus necessary. .--------. .--------. |IPFIX | |IPFIX | |Router#1|--------->|Mediator|---+ | | | | | '--------' '--------' | .---------. IP:10.1.1.1 IP:10.1.1.3 '----->| | ODID:10 ODID:0 |Collector| +----->| | .--------. | '---------' |IPFIX | | |Router#2|-----------------------' | | '--------' IP:10.1.1.2 ODID:20 Figure C: Loss of Observation Point Information. 5.2. Loss of Base Time Information The Export Time field included in the IPFIX header indicates the base time for Flow Records. In IPFIX Information Elements, described in [RFC5102], there are delta time fields that indicate the time difference from the value of the Export Time field. If the Flow Records include any delta time fields and the IPFIX Mediator overwrites the Export Time field when sending IPFIX messages, the delta time fields become meaningless and, because Collectors can not recognize this situation, wrong time values are propagated. 5.3. Loss of Option Template Information In some cases, depending on the implementation of the IPFIX Mediators, the information that is reported by the Option Templates could also be lost. If, for example, the sampling rate is not communicated to the Collectors, a Collector would miscalculate the traffic volume. This might bring crucial problems. Even if an IPFIX Mediator were to simply relay received Option Template Information, the value of its scope fields would become meaningless in the context of a different session. It should be noted that the minimal information to be communicated by an IPFIX Mediator needs to be defined. Kobayashi, et al. Expires November 1, 2008 [Page 13] Internet-Draft Mediation Problem Statement April 2008 5.4. Observation Domain ID and Template ID Management The Observation Domain ID is locally unique to the Exporting Process in an IPFIX Mediator, just like the Template ID is unique on the basis of the Observation Domain ID. These renewed identifiers should be managed using the Transport Session Information of the Collecting Process. If IPFIX Mediators could not manage the relations among these identifiers and the received Transport Session Information, the Mediators would, for example, relay wrong values for the scope fields of the Option Template and for a "Template Withdraw Message". In most cases, a Collector would not be able to interpret the Template ID of a "Template Withdraw Message" and the scope fields of an Option Template. The Collector would then shut down the IPFIX Session. 5.5. Transport Sessions Management How an IPFIX Mediator maintains relationships between the Transport Sessions of Collecting Processes and of Exporting Processes depends on its implementation. If multiple Transport Sessions of the Collecting Process are relayed to single Transport Session of the Exporting Process and the IPFIX Mediators shuts down the Transport Session of the Exporting Process, Flow Records on other Transport Sessions of the Collecting Processes would not be relayed at all. In the case of resetting a session of the Collecting Process, the behavior of the IPFIX Mediator needs to be defined. .--------. |IPFIX | |Router#1|----+ | | | '--------' X .--------. | .--------. .---------. |IPFIX | '---->|IPFIX | | | |Router#2|--------->|Mediator|----X---->|Collector| | | +---->| | | | '--------' | '--------' '---------' .--------. | |IPFIX | | |Router#3|----' | | '--------' Figure D: Relaying from Multiple Transport Sessions to Single Transport Session. Kobayashi, et al. Expires November 1, 2008 [Page 14] Internet-Draft Mediation Problem Statement April 2008 6. Conclusion This document has covered a multitude of problems related to the flow-based measurement system in IPFIX Mediation and described the applicability of IPFIX Mediators. In particular, section 4 listed several solutions to cope with huge traffic volumes. These problems can not be solved by simply adjusting the sampling rate and/or granularity of the Flow Records. The use of IPFIX Mediators, on the other hand, seems to be a means for constructing large-scale collection systems to achieve scalability. In addition, network operators can explore solutions by utilizing the advanced features of Exporters and Collectors. To assist the ability of the Exporters and Collectors, it should be noted that there are various IPFIX Mediators for the network providers to select from. Examples of the applicability of IPFIX Mediators are as follows. o Regarding Inter-domain IPFIX Exporting, IPFIX Mediators help network operators to anonymize or filter Flows, preventing privacy violations. o Regarding data retention, IPFIX Mediators enhance the storage of the measurement system. o Regarding interoperability, IPFIX Mediators provide interoperability between legacy protocols and IPFIX, even during the migration period to IPFIX. o Regarding the flow-based collector selection function, in integrated networks, which mix MPLS VPN and IPv4/IPv6, this could be utilized more frequently. More sophisticated implementation methods would enhance the effectiveness. o Regarding scalability in large-scale networks, IPFIX Mediators help to achieve high sample rates and fine-grained Flow analysis even as networks grow. As intermediate functions, Flow selection sampling or aggregation are beneficial. As a result, the benefits of IPFIX Mediation become apparent. However, there are still some open issues. o With the use of IPFIX Mediators, both Observation Point and IPFIX header information, such as the Exporter IP address, Observation Domain ID, and Export Time field, might be lost. This data should therefore be communicated between the Original Exporter and Collector via the IPFIX Mediator. o With the use of IPFIX Mediators, data advertised by Option Templates from the Original Exporter, such as the sampling rate Kobayashi, et al. Expires November 1, 2008 [Page 15] Internet-Draft Mediation Problem Statement April 2008 and sampling algorithm used, might be lost. If a Collector is not informed of current sampling rates, traffic information might become worthless. o IPFIX Mediators are required to manage Transport Sessions, Template IDs, and Observation Domain IDs. Otherwise, anomalous IPFIX messages could be created. These problems stem from the fact that no standards regarding IPFIX Mediation have been set. In particular, the minimum set of information which should be communicated between the Original Exporter and Collector, interworking between different IPFIX Transport Sessions, and the internal components of IPFIX Mediators should be standardized. Kobayashi, et al. Expires November 1, 2008 [Page 16] Internet-Draft Mediation Problem Statement April 2008 7. Security Considerations A flow-based measurement system might lead to privacy violations, such as the export of Flow Records to an outside address, if the system is not confined to the large-scale network under observation. General security issues of the IPFIX protocol are covered by the security considerations section in [RFC5101]. Security MUST be considered if different networks exchange Flow information. As the security of the exchange relies mostly on the protocol used, UDP does not seem appropriate for the exchange of information between networks. Kobayashi, et al. Expires November 1, 2008 [Page 17] Internet-Draft Mediation Problem Statement April 2008 8. IANA Considerations This document has no actions for IANA. Kobayashi, et al. Expires November 1, 2008 [Page 18] Internet-Draft Mediation Problem Statement April 2008 9. References 9.1. Normative References [RFC3917] Quittek, J., Zseby, T., Claise, B., and S. Zander, "Requirements for IP Flow Information Export(IPFIX)", October 2004. [RFC3954] Claise, B., "Cisco Systems NetFlow Services Export Version 9", October 2004. [RFC5101] Claise, B., "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information", January 2008. [RFC5102] Quittek, J., Bryant, S., Claise, B., Aitken, P., and J. Meyer, "Information Model for IP Flow Information Export", January 2008. 9.2. Informative References [I-D.dressler-ipfix-aggregation] Dressler, F., Sommer, C., Munz, G., and A. Kobayashi, "IPFIX Aggregation", draft-dressler-ipfix-aggregation-04.txt (work in progress) , November 2007. [I-D.peluso-flowselection] Peluso, L., Zseby, T., D'Antonio, S., and M. Molina, "Flow selection Techniques", draft-peluso-flowselection-tech-01.txt (work in progress) , November 2007. [TRAFGRW] Cho, K., Fukuda, K., Esaki, H., and A. Kato, "The Impact and Implications of the Growth in Residential User-to-User Traffic", SIGCOMM2006, pp. 207-218, Pisa, Italy, September 2006. , October 2006. Kobayashi, et al. Expires November 1, 2008 [Page 19] Internet-Draft Mediation Problem Statement April 2008 Authors' Addresses Atsushi Kobayashi NTT Information Sharing Platform Laboratories 3-9-11 Midori-cho Musashino-shi, Tokyo 180-8585 Japan Phone: +81-422-59-3978 Email: akoba@nttv6.net Haruhiko Nishida NTT Information Sharing Platform Laboratories 3-9-11 Midori-cho Musashino-shi, Tokyo 180-8585 Japan Phone: +81-422-59-3978 Email: nishida.haruhiko@lab.ntt.co.jp Christoph Sommer University of Erlangen-Nuremberg Department of Computer Science 7 Martensstr. 3 Erlangen 91058 Germany Phone: +49 9131 85-27993 Email: christoph.sommer@informatik.uni-erlangen.de URI: http://www7.informatik.uni-erlangen.de/~sommer/ Falko Dressler University of Erlangen-Nuremberg Department of Computer Science 7 Martensstr. 3 Erlangen 91058 Germany Phone: +49 9131 85-27914 Email: dressler@informatik.uni-erlangen.de URI: http://www7.informatik.uni-erlangen.de/~dressler/ Kobayashi, et al. Expires November 1, 2008 [Page 20] Internet-Draft Mediation Problem Statement April 2008 Emile Stephan France Telecom 2 avenue Pierre Marzin Lannion F-22307 France Phone: +33 2 96 05 18 52 Email: emile.stephan@orange-ftgroup.com Benoit Claise Cisco Systems De Kleetlaan 6a b1 Diegem 1831 Belgium Phone: +32 2 704 5622 Email: bclaise@cisco.com Kobayashi, et al. Expires November 1, 2008 [Page 21] Internet-Draft Mediation Problem Statement April 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. Kobayashi, et al. Expires November 1, 2008 [Page 22]