Network Working Group T. Dietz Internet-Draft NEC Europe Ltd. Intended status: Standards Track B. Claise Expires: January 15, 2009 P. Aitken Cisco Systems, Inc. F. Dressler University of Erlangen-Nuremberg G. Carle University of Tuebingen July 14, 2008 Information Model for Packet Sampling Exports 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 15, 2009. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 1] Internet-Draft PSAMP Information Model July 2008 Abstract This memo defines an information model for the Packet Sampling (PSAMP) protocol. It is used by the PSAMP protocol for encoding sampled packet data and information related to the Sampling process. As the PSAMP protocol is based on the IPFIX protocol, this information model is an extension to the IPFIX information model. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 2] Internet-Draft PSAMP Information Model July 2008 Conventions 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 RFC 2119 [RFC2119]. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. PSAMP Documents Overview . . . . . . . . . . . . . . . . . . . 6 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7 4. Relationship between PSAMP and IPFIX . . . . . . . . . . . . . 8 5. Properties of a PSAMP Information Element . . . . . . . . . . 9 6. Type Space . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7. Overloading Information Elements . . . . . . . . . . . . . . . 11 8. The PSAMP Information Elements . . . . . . . . . . . . . . . . 12 8.1. Identifiers (301-303) . . . . . . . . . . . . . . . . . . 12 8.1.1. selectionSequenceId . . . . . . . . . . . . . . . . . 13 8.1.2. selectorId . . . . . . . . . . . . . . . . . . . . . . 13 8.1.3. informationElementId . . . . . . . . . . . . . . . . . 13 8.2. Sampling Configuration (304-311) . . . . . . . . . . . . . 14 8.2.1. selectorAlgorithm . . . . . . . . . . . . . . . . . . 14 8.2.2. samplingPacketInterval . . . . . . . . . . . . . . . . 16 8.2.3. samplingPacketSpace . . . . . . . . . . . . . . . . . 16 8.2.4. samplingTimeInterval . . . . . . . . . . . . . . . . . 17 8.2.5. samplingTimeSpace . . . . . . . . . . . . . . . . . . 17 8.2.6. samplingSize . . . . . . . . . . . . . . . . . . . . . 18 8.2.7. samplingPopulation . . . . . . . . . . . . . . . . . . 18 8.2.8. samplingProbability . . . . . . . . . . . . . . . . . 19 8.3. Hash Configuration (326-334) . . . . . . . . . . . . . . . 19 8.3.1. digestHashValue . . . . . . . . . . . . . . . . . . . 19 8.3.2. hashIPPayloadOffset . . . . . . . . . . . . . . . . . 20 8.3.3. hashIPPayloadSize . . . . . . . . . . . . . . . . . . 20 8.3.4. hashOutputRangeMin . . . . . . . . . . . . . . . . . . 20 8.3.5. hashOutputRangeMax . . . . . . . . . . . . . . . . . . 21 8.3.6. hashSelectedRangeMin . . . . . . . . . . . . . . . . . 21 8.3.7. hashSelectedRangeMax . . . . . . . . . . . . . . . . . 21 8.3.8. hashDigestOutput . . . . . . . . . . . . . . . . . . . 22 8.3.9. hashInitialiserValue . . . . . . . . . . . . . . . . . 22 8.4. Time Stamps (322-325) . . . . . . . . . . . . . . . . . . 22 Dietz, et al. draft-ietf-psamp-info-09.txt [Page 3] Internet-Draft PSAMP Information Model July 2008 8.4.1. observationTimeSeconds . . . . . . . . . . . . . . . . 23 8.4.2. observationTimeMilliseconds . . . . . . . . . . . . . 23 8.4.3. observationTimeMicroseconds . . . . . . . . . . . . . 23 8.4.4. observationTimeNanoseconds . . . . . . . . . . . . . . 24 8.5. Packet Data (312-317) . . . . . . . . . . . . . . . . . . 24 8.5.1. dataLinkFrameSize . . . . . . . . . . . . . . . . . . 24 8.5.2. ipHeaderPacketSection . . . . . . . . . . . . . . . . 25 8.5.3. ipPayloadPacketSection . . . . . . . . . . . . . . . . 25 8.5.4. dataLinkFrameSection . . . . . . . . . . . . . . . . . 26 8.5.5. mplsLabelStackSection . . . . . . . . . . . . . . . . 27 8.5.6. mplsPayloadPacketSection . . . . . . . . . . . . . . . 27 8.6. Statistics (318-321) . . . . . . . . . . . . . . . . . . . 28 8.6.1. SelectorIdTotalPacketsObserved . . . . . . . . . . . . 28 8.6.2. SelectorIdTotalPacketsSelected . . . . . . . . . . . . 29 8.6.3. fixedError . . . . . . . . . . . . . . . . . . . . . . 29 8.6.4. relativeError . . . . . . . . . . . . . . . . . . . . 29 9. Security Considerations . . . . . . . . . . . . . . . . . . . 31 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32 10.1. Related Considerations . . . . . . . . . . . . . . . . . . 32 10.2. PSAMP Related Considerations . . . . . . . . . . . . . . . 32 11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 33 11.1. Normative References . . . . . . . . . . . . . . . . . . . 33 11.2. Informative References . . . . . . . . . . . . . . . . . . 33 Appendix A. Formal Specification of PSAMP Information Elements . 35 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 50 Intellectual Property and Copyright Statements . . . . . . . . . . 52 Dietz, et al. draft-ietf-psamp-info-09.txt [Page 4] Internet-Draft PSAMP Information Model July 2008 1. Introduction Packet Sampling techniques are required for various measurement scenarios. The Packet Sampling (PSAMP) protocol provides mechanisms for packet selection using different Filtering and Sampling techniques. A standardized way for the export and storage is required. The definition of the PSAMP information and data model is based on the IPFIX Information Model [RFC5102]. The PSAMP protocol document [I-D.ietf-psamp-protocol] specifies how to use the IPFIX protocol in the PSAMP context. This document examines the IPFIX Information Model [RFC5102] and extends it to meet the PSAMP requirements [RFC3917]. Therefore, the structure of this document is strongly based on the IPFIX document. It complements the PSAMP protocol specification by providing an appropriate PSAMP information model. The main part of this document, section 8, defines the list of Information Elements to be transmitted by the PSAMP protocol. Sections 5 and 6 describe the data types and Information Element properties used within this document and their relationship to the IPFIX information model. The main body of section 8 was generated from an XML document. The XML-based specification of the PSAMP Information Elements can be used for automatically checking syntactical correctness of the specification. Furthermore it can be used - in combination with the IPFIX information model - for automated code generation. The resulting code can be used in PSAMP protocol implementations to deal with processing PSAMP information elements. For that reason, the XML document that served as the source for section 8 is attached to this document in Appendix A. Note that although partially generated from the attached XML documents, the main body of this document is normative while the appendices are informational. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 5] Internet-Draft PSAMP Information Model July 2008 2. PSAMP Documents Overview [I-D.ietf-psamp-framework]: "A Framework for Packet Selection and Reporting", describes the PSAMP framework for network elements to select subsets of packets by statistical and other methods, and to export a stream of reports on the selected packets to a collector. [I-D.ietf-psamp-sample-tech]: "Sampling and Filtering Techniques for IP Packet Selection", describes the set of packet selection techniques supported by PSAMP. [I-D.ietf-psamp-protocol]: "Packet Sampling (PSAMP) Protocol Specifications" specifies the export of packet information from a PSAMP Exporting Process to a PSAMP Collecting Process. This document, "Information Model for Packet Sampling Exports", defines an information and data model for PSAMP. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 6] Internet-Draft PSAMP Information Model July 2008 3. Terminology IPFIX-specific terminology used in this document is defined in Section 2 of [RFC5101]. PSAMP-specific terminology used in this document is defined in Section 3.2 of [I-D.ietf-psamp-protocol]. As in [RFC5101] and [I-D.ietf-psamp-protocol], these IPFIX- and PSAMP- specific terms have the first letter of a word capitalized when used in this document. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 7] Internet-Draft PSAMP Information Model July 2008 4. Relationship between PSAMP and IPFIX As described in the PSAMP protocol [I-D.ietf-psamp-protocol] a PSAMP Report can be seen as a very special IPFIX Data Record. It represents an IPFIX Flow containing only a single packet. Therefore, the IPFIX information model can be used as a basis for PSAMP Reports. Nevertheless, there are properties required in PSAMP Reports which cannot be modelled using the current IPFIX information model. This document describes extensions to the IPFIX information model which allow the modelling of information and data required by PSAMP. Some of these extensions allow the export of what may be considered sensitive information. Refer to the Security Considerations section for a fuller discussion. Note that the export of sampled or filtered PSAMP Reports may not need all the Information Elements defined by the IPFIX information model [RFC5102], as discussed in sections 6.2 and 6.3 of the PSAMP Framework [I-D.ietf-psamp-framework]. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 8] Internet-Draft PSAMP Information Model July 2008 5. Properties of a PSAMP Information Element The PSAMP Information Elements are defined in accordance with sections 2.1 to 2.3 of the IPFIX Information Model [RFC5102] to which reference should be made for more information. Nevertheless, we strongly recommend defining the optional "units" property for every information element (if applicable). The Data Types defined in section 3.1 of the IPFIX Information Model [RFC5102] are also used for the PSAMP Information Elements. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 9] Internet-Draft PSAMP Information Model July 2008 6. Type Space The PSAMP Information Elements MUST be constructed from the basic abstract data types and data type semantics described in section 3 of the IPFIX Information Model [RFC5102]. To ensure consistency between IPFIX and PSAMP, the data types are not repeated in this document. The encoding of these data types is described in the IPFIX Protocol [RFC5101]. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 10] Internet-Draft PSAMP Information Model July 2008 7. Overloading Information Elements Information Elements SHOULD NOT be overloaded with multiple meanings or re-used for multiple purposes. Different Information Elements SHOULD be allocated for each requirement. In particular, further information SHALL be encoded in new Information Elements as necessary, and SHALL NOT be encoded in or inferred from the selection method. Although the presence of certain other Information Elements allows the selection method to be inferred, a separate Information Element is provided for the selectorAlgorithm to include as scope for the Selector Report Interpretation [I-D.ietf-psamp-protocol]. Even if the Information Elements are specified with a specific selection method (i.e. a specific value of selectorAlgorithm) in mind, these Information Elements are not restricted to the selection method and MAY be used for different selection methods in the future. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 11] Internet-Draft PSAMP Information Model July 2008 8. The PSAMP Information Elements This section describes the Information Elements used by the PSAMP protocol. For each Information Element specified in sections 8.1 - 8.6 below a unique identifier is allocated in accordance with section 4 of the IPFIX information model [RFC5102]. The assignments are controlled by IANA as an extension of the IPFIX Information Model. The Information Elements specified by the IPFIX information model [RFC5102] are used by the PSAMP protocol where applicable. To avoid inconsistencies between the IPFIX and the PSAMP information and data models, only those Information Elements that are not already described by the IPFIX information model are defined here. List of additional PSAMP Information Elements: +-----+--------------------------+-----+-------------------------------+ | ID | Name | ID | Name | +-----+--------------------------+-----+-------------------------------+ | 301 | selectionSequenceId | 318 | SelectorIdTotalPacketsObserved| | 302 | selectorId | 319 | SelectorIdTotalPacketsSelected| | 303 | informationElementId | 320 | fixedError | | 304 | selectorAlgorithm | 321 | relativeError | | 305 | samplingPacketInterval | 322 | observationTimeSeconds | | 306 | samplingPacketSpace | 323 | observationTimeMilliseconds | | 307 | samplingTimeInterval | 324 | observationTimeMicroseconds | | 308 | samplingTimeSpace | 325 | observationTimeNanoseconds | | 309 | samplingSize | 326 | digestHashValue | | 310 | samplingPopulation | 327 | hashIPPayloadOffset | | 311 | samplingProbability | 328 | hashIPPayloadSize | | 312 | dataLinkFrameSize | 329 | hashOutputRangeMin | | 313 | ipHeaderPacketSection | 330 | hashOutputRangeMax | | 314 | ipPayloadPacketSection | 331 | hashSelectedRangeMin | | 315 | dataLinkFrameSection | 332 | hashSelectedRangeMax | | 316 | mplsLabelStackSection | 333 | hashDigestOutput | | 317 | mplsPayloadPacketSection | 334 | hashInitialiserValue | +-----+--------------------------+-----+-------------------------------+ 8.1. Identifiers (301-303) Information Elements in this section serve as identifiers. All of them have an integral abstract data type and data type semantics "identifier". Dietz, et al. draft-ietf-psamp-info-09.txt [Page 12] Internet-Draft PSAMP Information Model July 2008 +-----+----------------------------+-----+----------------------------+ | ID | Name | ID | Name | +-----+----------------------------+-----+----------------------------+ | 301 | selectionSequenceId | 303 | informationElementId | | 302 | selectorId | | | +-----+----------------------------+-----+----------------------------+ 8.1.1. selectionSequenceId Description: From all the packets observed at an Observation Point, a subset of the packets is selected by a sequence of one or more Selectors. The selectionSequenceId is a unique value per Observation Domain, specifying the Observation Point and the sequence of Selectors through which the packets are selected. Abstract Data Type: unsigned64 Data Type Semantics: identifier ElementId: 301 Status: current 8.1.2. selectorId Description: The Selector ID is the unique ID identifying a Primitive Selector. Each Primitive Selector must have a unique ID in the Observation Domain. Abstract Data Type: unsigned16 Data Type Semantics: identifier ElementId: 302 Status: current 8.1.3. informationElementId Description: Dietz, et al. draft-ietf-psamp-info-09.txt [Page 13] Internet-Draft PSAMP Information Model July 2008 This Information Element contains the ID of another Information Element. Abstract Data Type: unsigned16 Data Type Semantics: identifier ElementId: 303 Status: current 8.2. Sampling Configuration (304-311) Information Elements in this section can be used for describing the sampling configuration of a Selection Process. +-----+----------------------------+-----+----------------------------+ | ID | Name | ID | Name | +-----+----------------------------+-----+----------------------------+ | 304 | selectorAlgorithm | 308 | samplingTimeSpace | | 305 | samplingPacketInterval | 309 | samplingSize | | 306 | samplingPacketSpace | 310 | samplingPopulation | | 307 | samplingTimeInterval | 311 | samplingProbability | +-----+----------------------------+-----+----------------------------+ 8.2.1. selectorAlgorithm Description: This Information Element identifies the packet selection algorithm (e.g., Filtering, Sampling) that are applied by the Selection Process. Most of these algorithms have parameters. Further Information Elements are needed for fully specifying packet selection with these algorithms and all their parameters. The algorithms listed below are defined in [I-D.ietf-psamp-sample- tech]. For their parameters, Information Elements are defined in the Information Model Document [I-D.ietf-psamp-info]. The names of these Information Elements are listed for each algorithm identifier. Further algorithm identifiers may be added to the list below. For specifying their parameters it might be necessary to define new Information Elements. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 14] Internet-Draft PSAMP Information Model July 2008 The following packet selection algorithms identifiers are defined in [I-D.ietf-psamp-info]: ID Algorithm ------------------------------------ 1 Systematic count-based Sampling Parameters: samplingPacketInterval samplingPacketSpace 2 Systematic time-based Sampling Parameters: samplingTimeInterval samplingTimeSpace 3 Random n-out-of-N Sampling Parameters: samplingSize samplingPopulation 4 Uniform probabilistic Sampling Parameter: samplingProbability 5 Property match Filtering There is a broad variety of parameters that could be used here but currently there are no agreed parameters specified. 6 Hash based Filtering using BOB 7 Hash based Filtering using IPSX 8 Hash based Filtering using CRC Parameters for IDs 6 - 8: hashInitialiserValue hashIPPayloadOffset hashIPPayloadSize hashSelectedRangeMin hashSelectedRangeMax hashOutputRangeMin hashOutputRangeMax New assignments for the PSAMP selection algorithms will be administered by IANA, and subject to Expert Review [RFC5226]. The group of experts must double check the Information Elements definitions with already defined Information Elements for completeness, accuracy and redundancy. Those experts will initially be drawn from the Working Group Chairs and document editors of the IPFIX and PSAMP Working Groups. The selectorAlgorithm registry is maintained by IANA and can be updated when specifications of the new algorithm(s) and any new Information Elements are provided. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 15] Internet-Draft PSAMP Information Model July 2008 Abstract Data Type: unsigned16 Data Type Semantics: identifier ElementId: 304 Status: current 8.2.2. samplingPacketInterval Description: This Information Element specifies the number of packets that are consecutively sampled. For example a value of 100 means that 100 consecutive packets are sampled. For example, this Information Element may be used to describe the configuration of a systematic count-based Sampling Selector. Abstract Data Type: unsigned32 Data Type Semantics: quantity ElementId: 305 Status: current Units: packets 8.2.3. samplingPacketSpace Description: This Information Element specifies the number of packets between two "samplingPacketInterval"s. A value of 100 means that the next interval starts 100 packets (which are not sampled) after the current "samplingPacketInterval" is over. For example, this Information Element may be used to describe the configuration of a systematic count-based Sampling Selector. Abstract Data Type: unsigned32 Data Type Semantics: quantity Dietz, et al. draft-ietf-psamp-info-09.txt [Page 16] Internet-Draft PSAMP Information Model July 2008 ElementId: 306 Status: current Units: packets 8.2.4. samplingTimeInterval Description: This Information Element specifies the time interval in microseconds during which all arriving packets are sampled. For example, this Information Element may be used to describe the configuration of a systematic time-based Sampling Selector. Abstract Data Type: dateTimeMicroseconds Data Type Semantics: quantity ElementId: 307 Status: current Units: microseconds 8.2.5. samplingTimeSpace Description: This Information Element specifies the time interval in microseconds between two "samplingTimeInterval"s. A value of 100 means that the next interval starts 100 microseconds (during which no packets are sampled) after the current "samplingTimeInterval" is over. For example, this Information Element may used to describe the configuration of a systematic time-based Sampling Selector. Abstract Data Type: dateTimeMicroseconds Data Type Semantics: quantity ElementId: 308 Dietz, et al. draft-ietf-psamp-info-09.txt [Page 17] Internet-Draft PSAMP Information Model July 2008 Status: current Units: microseconds 8.2.6. samplingSize Description: This Information Element specifies the number of elements taken from the parent Population for random Sampling algorithms. For example, this Information Element may be used to describe the configuration of a random n-out-of-N Sampling Selector. Abstract Data Type: unsigned32 Data Type Semantics: quantity ElementId: 309 Status: current Units: packets 8.2.7. samplingPopulation Description: This Information Element specifies the number of elements in the parent Population for random Sampling algorithms. For example, this Information Element may be used to describe the configuration of a random n-out-of-N Sampling Selector. Abstract Data Type: unsigned32 Data Type Semantics: quantity ElementId: 310 Status: current Units: packets Dietz, et al. draft-ietf-psamp-info-09.txt [Page 18] Internet-Draft PSAMP Information Model July 2008 8.2.8. samplingProbability Description: This Information Element specifies the probability that a packet is sampled, expressed as a value between 0 and 1. The probability is equal for every packet. A value of 0 means no packet was sampled since the probability is 0. For example, this Information Element may be used to describe the configuration of a uniform probabilistic Sampling Selector. Abstract Data Type: float64 Data Type Semantics: quantity ElementId: 311 Status: current 8.3. Hash Configuration (326-334) The following Information Elements can be used for describing the sampling configuration of a Selection Process. +-----+----------------------------+-----+----------------------------+ | ID | Name | ID | Name | +-----+----------------------------+-----+----------------------------+ | 326 | digestHashValue | 331 | hashSelectedRangeMin | | 327 | hashIPPayloadOffset | 332 | hashSelectedRangeMax | | 328 | hashIPPayloadSize | 333 | hashDigestOutput | | 329 | hashOutputRangeMin | 334 | hashInitialiserValue | | 330 | hashOutputRangeMax | | | +-----+----------------------------+-----+----------------------------+ 8.3.1. digestHashValue Description: This Information Element specifies the value from the digest hash function. Abstract Data Type: unsigned64 Data Type Semantics: quantity Dietz, et al. draft-ietf-psamp-info-09.txt [Page 19] Internet-Draft PSAMP Information Model July 2008 ElementId: 326 Status: current 8.3.2. hashIPPayloadOffset Description: This Information Element specifies the IP payload offset used by a hash based Selector. Abstract Data Type: unsigned64 Data Type Semantics: quantity ElementId: 327 Status: current 8.3.3. hashIPPayloadSize Description: This Information Element specifies the IP payload size used by a hash based Selector. Abstract Data Type: unsigned64 Data Type Semantics: quantity ElementId: 328 Status: current 8.3.4. hashOutputRangeMin Description: This Information Element specifies the value for the beginning of a hash function's potential output range. Abstract Data Type: unsigned64 Data Type Semantics: quantity Dietz, et al. draft-ietf-psamp-info-09.txt [Page 20] Internet-Draft PSAMP Information Model July 2008 ElementId: 329 Status: current 8.3.5. hashOutputRangeMax Description: This Information Element specifies the value for the end of a hash function's potential output range. Abstract Data Type: unsigned64 Data Type Semantics: quantity ElementId: 330 Status: current 8.3.6. hashSelectedRangeMin Description: This Information Element specifies the value for the beginning of a hash function's selected range. Abstract Data Type: unsigned64 Data Type Semantics: quantity ElementId: 331 Status: current 8.3.7. hashSelectedRangeMax Description: This Information Element specifies the value for the end of a hash function's selected range. Abstract Data Type: unsigned64 Data Type Semantics: quantity Dietz, et al. draft-ietf-psamp-info-09.txt [Page 21] Internet-Draft PSAMP Information Model July 2008 ElementId: 332 Status: current 8.3.8. hashDigestOutput Description: This Information Element contains a boolean value which is TRUE if the output from this hash Selector has been configured to be included in the packet report as a packet digest, else FALSE. Abstract Data Type: boolean Data Type Semantics: quantity ElementId: 333 Status: current 8.3.9. hashInitialiserValue Description: This Information Element specifies the initialiser value to the hash function. Abstract Data Type: unsigned64 Data Type Semantics: quantity ElementId: 334 Status: current 8.4. Time Stamps (322-325) The Information Elements listed below contain time stamps. They can be used for reporting the observation time of a single packet. +-----+----------------------------+-----+----------------------------+ | ID | Name | ID | Name | +-----+----------------------------+-----+----------------------------+ | 322 | observationTimeSeconds | 324 | observationTimeMicroseconds| | 323 | observationTimeMilliseconds| 325 | observationTimeNanoseconds | +-----+----------------------------+-----+----------------------------+ Dietz, et al. draft-ietf-psamp-info-09.txt [Page 22] Internet-Draft PSAMP Information Model July 2008 8.4.1. observationTimeSeconds Description: This Information Element specifies the absolute time in seconds of an observation. Abstract Data Type: dateTimeSeconds Data Type Semantics: quantity ElementId: 322 Status: current Units: seconds 8.4.2. observationTimeMilliseconds Description: This Information Element specifies the absolute time in milliseconds of an observation. Abstract Data Type: dateTimeMilliseconds Data Type Semantics: quantity ElementId: 323 Status: current Units: milliseconds 8.4.3. observationTimeMicroseconds Description: This Information Element specifies the absolute time in microseconds of an observation. Abstract Data Type: dateTimeMicroseconds Data Type Semantics: quantity Dietz, et al. draft-ietf-psamp-info-09.txt [Page 23] Internet-Draft PSAMP Information Model July 2008 ElementId: 324 Status: current Units: microseconds 8.4.4. observationTimeNanoseconds Description: This Information Element specifies the absolute time in nanoseconds of an observation. Abstract Data Type: dateTimeNanoseconds Data Type Semantics: quantity ElementId: 325 Status: current Units: nanoseconds 8.5. Packet Data (312-317) The following Information Elements are all used for reporting raw content of a packet. The only exception is dataLinkFrameSize that reports the size of the related data link frame. All other Information Elements contain sections of the raw packet. +-----+----------------------------+-----+----------------------------+ | ID | Name | ID | Name | +-----+----------------------------+-----+----------------------------+ | 312 | dataLinkFrameSize | 315 | dataLinkFrameSection | | 313 | ipHeaderPacketSection | 316 | mplsLabelStackSection | | 314 | ipPayloadPacketSection | 317 | mplsPayloadPacketSection | +-----+----------------------------+-----+----------------------------+ 8.5.1. dataLinkFrameSize Description: This Information Element specifies the size of the sampled data link frame, and SHOULD be checked before analysing higher layer protocols. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 24] Internet-Draft PSAMP Information Model July 2008 The data link layer is defined in [ISO_IEC.7498-1_1994]. Abstract Data Type: unsigned32 Data Type Semantics: quantity ElementId: 312 Status: current 8.5.2. ipHeaderPacketSection Description: This Information Element, which may have a variable length, carries a series of octets from the start of the IP header of a sampled packet. With sufficient length, this element also reports octets from the IP payload, subject to [RFC2804]. See the Security Considerations section. The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. Abstract Data Type: octetArray Data Type Semantics: quantity ElementId: 313 Status: current 8.5.3. ipPayloadPacketSection Description: This Information Element, which may have a variable length, carries a series of octets from the start of the IP payload of a sampled packet. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 25] Internet-Draft PSAMP Information Model July 2008 The IPv4 payload is that part of the packet which follows the IPv4 header and any options, which [RFC0791] refers to as "data" or "data octets". e.g., see the examples in [RFC0791] APPENDIX A. The IPv6 payload is the rest of the packet following the 40 octet IPv6 header. Note that any extension headers present are considered part of the payload. See [RFC2460] for the IPv6 specification. The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. Abstract Data Type: octetArray Data Type Semantics: quantity ElementId: 314 Status: current 8.5.4. dataLinkFrameSection Description: This Information Element, which may have a variable length, carries the first n octets from the data link frame of a sampled packet. The data link layer is defined in [ISO_IEC.7498-1_1994]. The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. Abstract Data Type: octetArray Data Type Semantics: quantity Dietz, et al. draft-ietf-psamp-info-09.txt [Page 26] Internet-Draft PSAMP Information Model July 2008 ElementId: 315 Status: current 8.5.5. mplsLabelStackSection Description: This Information Element, which may have a variable length, carries the first n octets from the MPLS label stack of a sampled packet. With sufficient length, this element also reports octets from the MPLS payload, subject to [RFC2804]. See the Security Considerations section. See [RFC3031] for the specification of MPLS packets. See [RFC3032] for the specification of the MPLS label stack. The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. Abstract Data Type: octetArray Data Type Semantics: quantity ElementId: 316 Status: current 8.5.6. mplsPayloadPacketSection Description: This Information Element, which may have a variable length, carries the first n octets from the MPLS payload of a sampled packet, being data that follows immediately after the MPLS label stack. See [RFC3031] for the specification of MPLS packets. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 27] Internet-Draft PSAMP Information Model July 2008 See [RFC3032] for the specification of the MPLS label stack. The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. Abstract Data Type: octetArray Data Type Semantics: quantity ElementId: 317 Status: current 8.6. Statistics (318-321) Information Elements in this section can be used for reporting statistics from the Metering Process. +-----+-------------------------------+-----+--------------------------+ | ID | Name | ID | Name | +-----+-------------------------------+-----+--------------------------+ | 318 | SelectorIdTotalPacketsObserved| 320 | fixedError | | 319 | SelectorIdTotalPacketsSelected| 321 | relativeError | +-----+-------------------------------+-----+--------------------------+ 8.6.1. SelectorIdTotalPacketsObserved Description: This Information Element specifies the total number of packets observed by a Selector, for a specific value of SelectorId. Abstract Data Type: unsigned64 Data Type Semantics: totalCounter ElementId: 318 Status: current Units: packets Dietz, et al. draft-ietf-psamp-info-09.txt [Page 28] Internet-Draft PSAMP Information Model July 2008 8.6.2. SelectorIdTotalPacketsSelected Description: This Information Element specifies the total number of packets selected by a Selector, for a specific value of SelectorId. Abstract Data Type: unsigned64 Data Type Semantics: totalCounter ElementId: 319 Status: current Units: packets 8.6.3. fixedError Description: This Information Element specifies the maximum possible positive or negative error interval of the reported value for a given Information Element. Abstract Data Type: float64 Data Type Semantics: quantity ElementId: 320 Status: current Units: The units of the Information Element for which the error is specified. 8.6.4. relativeError Description: This Information Element specifies the maximum possible positive or negative error ratio for a given Information Element. Abstract Data Type: float64 Dietz, et al. draft-ietf-psamp-info-09.txt [Page 29] Internet-Draft PSAMP Information Model July 2008 Data Type Semantics: quantity ElementId: 321 Status: current Dietz, et al. draft-ietf-psamp-info-09.txt [Page 30] Internet-Draft PSAMP Information Model July 2008 9. Security Considerations The PSAMP information model itself does not directly introduce security issues. Rather it defines a set of attributes which may for privacy or business issues be considered sensitive information. For example, exporting values of header fields may make attacks possible for the receiver of this information, which would otherwise only be possible for direct observers of the reported Flows along the data path. Specifically, the Information Elements pertaining to packet sections MUST target no more than the packet header, some subsequent bytes of the packet, and encapsulating headers if present. Full packet capture of arbitrary packet streams is explicitly out of scope, per [RFC2804]. The underlying protocol used to exchange the information described here must therefore apply appropriate procedures to guarantee the integrity and confidentiality of the exported information. Such protocols are defined in separate documents, specifically the IPFIX protocol document [RFC5101]. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 31] Internet-Draft PSAMP Information Model July 2008 10. IANA Considerations The PSAMP Information Model, as set out in this document, has two sets of assigned numbers. Considerations for assigning them are discussed in this section, using the example policies as set out in the "Guidelines for IANA Considerations" document [RFC5226] 10.1. Related Considerations As the PSAMP protocol uses the IPFIX protocol, refer to the IANA considerations section in [RFC5102] for the assignments of numbers used in the protocol and for the numbers used in the information model. 10.2. PSAMP Related Considerations This document specifies an initial set of PSAMP Information Elements fulfilling the needs specified in [I-D.ietf-psamp-sample-tech], as an extension to the IPFIX Information Elements [RFC5102]. Note that the PSAMP Information Element IDs were initially started at the value 301, in order to leave a gap for any ongoing IPFIX work requiring new Information Elements. It is expected that this gap in the Information Element numbering will be filled in by IANA with new IPFIX Information Elements. Each new selection method MUST be assigned a unique value for the selectorAlgorithm Information Element. Initial contents of this registry are found section 8.2.4. Its configuration parameter(s), along with the way to report it/them with an Options Template, MUST be clearly specified. New assignments for the PSAMP selection method will be administered by IANA and subject to Expert Review [RFC5226]. The group of experts must double check the Information Elements definitions with already defined Information Elements for completeness, accuracy and redundancy. Those experts will initially be drawn from the Working Group Chairs and document editors of the IPFIX and PSAMP Working Groups. The selectorAlgorithm registry is maintained by IANA and can be updated as long as specifications of the new method(s) and any new Information Elements are provided. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 32] Internet-Draft PSAMP Information Model July 2008 11. References 11.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008. [RFC5101] Claise, B., "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of IP Traffic Flow Information", RFC 5101, January 2008. [RFC5102] Quittek, J., Bryant, S., Claise, B., Aitken, P., and J. Meyer, "Information Model for IP Flow Information Export", RFC 5102, January 2008. [ISO_IEC.7498-1_1994] International Organization for Standardization, "Information technology -- Open Systems Interconnection -- Basic Reference Model: The Basic Mode", ISO Standard 7498- 1:1994, June 1996. [I-D.ietf-psamp-info] Dietz, T., Claise, B., Aitken, P., Dressler, F., and G. Carle, "Information Model for Packet Sampling Exports", draft-ietf-psamp-info-08 (work in progress), February 2008. [I-D.ietf-psamp-sample-tech] Zseby, T., "Sampling and Filtering Techniques for IP Packet Selection", draft-ietf-psamp-sample-tech-11 (work in progress), July 2008. [I-D.ietf-psamp-protocol] Claise, B., "Packet Sampling (PSAMP) Protocol Specifications", draft-ietf-psamp-protocol-09 (work in progress), December 2007. 11.2. Informative References [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1981. [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 33] Internet-Draft PSAMP Information Model July 2008 [RFC2629] Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629, June 1999. [RFC2804] IAB and IESG, "IETF Policy on Wiretapping", RFC 2804, May 2000. [RFC3031] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol Label Switching Architecture", RFC 3031, January 2001. [RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y., Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack Encoding", RFC 3032, January 2001. [RFC3917] Quittek, J., Zseby, T., Claise, B., and S. Zander, "Requirements for IP Flow Information Export (IPFIX)", RFC 3917, October 2004. [I-D.ietf-ipfix-architecture] Sadasivan, G., "Architecture for IP Flow Information Export", draft-ietf-ipfix-architecture-12 (work in progress), September 2006. [I-D.ietf-psamp-framework] Chiou, D., Claise, B., Duffield, N., Greenberg, A., Grossglauser, M., Rexford, J., and S. Goldberg, "A Framework for Packet Selection and Reporting", draft-ietf-psamp-framework-13 (work in progress), June 2008. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 34] Internet-Draft PSAMP Information Model July 2008 Appendix A. Formal Specification of PSAMP Information Elements This appendix contains a formal description of the PSAMP information model XML document. Note that this appendix is of informational nature, while the text in section Section 8 generated from this appendix is normative. Using a formal and machine readable syntax for the information model enables the creation of PSAMP aware tools which can automatically adapt to extensions to the information model, by simply reading updated information model specifications. The wide availability of XML aware tools and libraries for client devices is a primary consideration for this choice. In particular libraries for parsing XML documents are readily available. Also mechanisms such as the Extensible Stylesheet Language (XSL) allow for transforming a source XML document into other documents. This draft was authored in XML and transformed according to [RFC2629]. It should be noted that the use of XML in exporters, collectors or other tools is not mandatory for the deployment of PSAMP. In particular, exporting processes do not produce or consume XML as part of their operation. It is expected that PSAMP collectors MAY take advantage of the machine readability of the information model vs. hardcoding their behavior or inventing proprietary means for accommodating extensions. Using XML-based specifications does not currently address possible IANA implications associated with XML Namespace URIs. The use of Namespaces as an extension mechanism implies that an IANA registered Namespace URI should be available and that directory names below this base URI be assigned for relevant IETF specifications. The authors are not aware of this mechanism today. From all the packets observed at an Observation Point, a subset of the packets is selected by a sequence of one or more Selectors. The selectionSequenceId is a unique value per Observation Domain, specifying the Observation Point and the sequence of Selectors through which the packets are selected. The Selector ID is the unique ID identifying a Primitive Selector. Each Primitive Selector must have a unique ID in the Observation Domain. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 37] Internet-Draft PSAMP Information Model July 2008 This Information Element contains the ID of another Information Element. This Information Element identifies the packet selection algorithm (e.g., Filtering, Sampling) that are applied by the Selection Process. Most of these algorithms have parameters. Further Information Elements are needed for fully specifying packet selection with these algorithms and all their parameters. The algorithms listed below are defined in [I-D.ietf-psamp-sample-tech]. For their parameters, Information Elements are defined in the Information Model Document [I-D.ietf-psamp-info]. The names of these Information Elements are listed for each algorithm identifier. Further algorithm identifiers may be added to the list below. For specifying their parameters it might be necessary to define new Information Elements. The following packet selection algorithms identifiers are defined in [I-D.ietf-psamp-info]: ID Algorithm ------------------------------------ 1 Systematic count-based Sampling Parameters: samplingPacketInterval samplingPacketSpace 2 Systematic time-based Sampling Parameters: Dietz, et al. draft-ietf-psamp-info-09.txt [Page 38] Internet-Draft PSAMP Information Model July 2008 samplingTimeInterval samplingTimeSpace 3 Random n-out-of-N Sampling Parameters: samplingSize samplingPopulation 4 Uniform probabilistic Sampling Parameter: samplingProbability 5 Property match Filtering There is a broad variety of parameters that could be used here but currently there are no agreed parameters specified. 6 Hash based Filtering using BOB 7 Hash based Filtering using IPSX 8 Hash based Filtering using CRC Parameters for IDs 6 - 8: hashInitialiserValue hashIPPayloadOffset hashIPPayloadSize hashSelectedRangeMin hashSelectedRangeMax hashOutputRangeMin hashOutputRangeMax New assignments for the PSAMP selection algorithms will be administered by IANA, and subject to Expert Review [RFC5226]. The group of experts must double check the Information Elements definitions with already defined Information Elements for completeness, accuracy and redundancy. Those experts will initially be drawn from the Working Group Chairs and document editors of the IPFIX and PSAMP Working Groups. The selectorAlgorithm registry is maintained by IANA and can be updated when specifications of the new algorithm(s) and any new Information Elements are provided. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 39] Internet-Draft PSAMP Information Model July 2008 This Information Element specifies the number of packets that are consecutively sampled. For example a value of 100 means that 100 consecutive packets are sampled. For example, this Information Element may be used to describe the configuration of a systematic count-based Sampling Selector. packets This Information Element specifies the number of packets between two "samplingPacketInterval"s. A value of 100 means that the next interval starts 100 packets (which are not sampled) after the current "samplingPacketInterval" is over. For example, this Information Element may be used to describe the configuration of a systematic count-based Sampling Selector. packets This Information Element specifies the time interval in microseconds during which all arriving packets are sampled. For example, this Information Element may be used to describe the configuration of a systematic time-based Sampling Selector. microseconds Dietz, et al. draft-ietf-psamp-info-09.txt [Page 40] Internet-Draft PSAMP Information Model July 2008 This Information Element specifies the time interval in microseconds between two "samplingTimeInterval"s. A value of 100 means that the next interval starts 100 microseconds (during which no packets are sampled) after the current "samplingTimeInterval" is over. For example, this Information Element may used to describe the configuration of a systematic time-based Sampling Selector. microseconds This Information Element specifies the number of elements taken from the parent Population for random Sampling algorithms. For example, this Information Element may be used to describe the configuration of a random n-out-of-N Sampling Selector. packets This Information Element specifies the number of elements in the parent Population for random Sampling algorithms. For example, this Information Element may be used to describe the configuration of a random n-out-of-N Sampling Selector. packets Dietz, et al. draft-ietf-psamp-info-09.txt [Page 41] Internet-Draft PSAMP Information Model July 2008 This Information Element specifies the probability that a packet is sampled, expressed as a value between 0 and 1. The probability is equal for every packet. A value of 0 means no packet was sampled since the probability is 0. For example, this Information Element may be used to describe the configuration of a uniform probabilistic Sampling Selector. This Information Element specifies the size of the sampled data link frame, and SHOULD be checked before analysing higher layer protocols. The data link layer is defined in [ISO_IEC.7498-1_1994]. This Information Element, which may have a variable length, carries a series of octets from the start of the IP header of a sampled packet. With sufficient length, this element also reports octets from the IP payload, subject to [RFC2804]. See the Security Considerations section. The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, Dietz, et al. draft-ietf-psamp-info-09.txt [Page 42] Internet-Draft PSAMP Information Model July 2008 then a new Template MUST be used. This Information Element, which may have a variable length, carries a series of octets from the start of the IP payload of a sampled packet. The IPv4 payload is that part of the packet which follows the IPv4 header and any options, which [RFC0791] refers to as "data" or "data octets". e.g., see the examples in [RFC0791] APPENDIX A. The IPv6 payload is the rest of the packet following the 40 octet IPv6 header. Note that any extension headers present are considered part of the payload. See [RFC2460] for the IPv6 specification. The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. This Information Element, which may have a variable length, carries the first n octets from the data link frame of a sampled packet. The data link layer is defined in [ISO_IEC.7498-1_1994]. The size of the exported section may be constrained due to limitations in the IPFIX protocol. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 43] Internet-Draft PSAMP Information Model July 2008 The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. This Information Element, which may have a variable length, carries the first n octets from the MPLS label stack of a sampled packet. With sufficient length, this element also reports octets from the MPLS payload, subject to [RFC2804]. See the Security Considerations section. See [RFC3031] for the specification of MPLS packets. See [RFC3032] for the specification of the MPLS label stack. The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. This Information Element, which may have a variable length, carries the first n octets from the MPLS payload of a sampled packet, being data that follows immediately after the MPLS label stack. See [RFC3031] for the specification of MPLS packets. See [RFC3032] for the specification of the MPLS label stack. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 44] Internet-Draft PSAMP Information Model July 2008 The size of the exported section may be constrained due to limitations in the IPFIX protocol. The data for this field MUST NOT be padded. If insufficient octets are available for the length specified in the Template, then a new Template MUST be used. This Information Element specifies the total number of packets observed by a Selector, for a specific value of SelectorId. packets This Information Element specifies the total number of packets selected by a Selector, for a specific value of SelectorId. packets This Information Element specifies the maximum possible positive or negative error interval of the reported value for a given Information Element. The units of the Information Element for which the error is specified. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 45] Internet-Draft PSAMP Information Model July 2008 This Information Element specifies the maximum possible positive or negative error ratio for a given Information Element. This Information Element specifies the absolute time in seconds of an observation. seconds This Information Element specifies the absolute time in milliseconds of an observation. milliseconds This Information Element specifies the absolute time in microseconds of an observation. microseconds Dietz, et al. draft-ietf-psamp-info-09.txt [Page 46] Internet-Draft PSAMP Information Model July 2008 This Information Element specifies the absolute time in nanoseconds of an observation. nanoseconds This Information Element specifies the value from the digest hash function. This Information Element specifies the IP payload offset used by a hash based Selector. This Information Element specifies the IP payload size used by a hash based Selector. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 47] Internet-Draft PSAMP Information Model July 2008 This Information Element specifies the value for the beginning of a hash function's potential output range. This Information Element specifies the value for the end of a hash function's potential output range. This Information Element specifies the value for the beginning of a hash function's selected range. This Information Element specifies the value for the end of a hash function's selected range. This Information Element contains a boolean value which is TRUE if the output from this hash Selector has been configured to be Dietz, et al. draft-ietf-psamp-info-09.txt [Page 48] Internet-Draft PSAMP Information Model July 2008 included in the packet report as a packet digest, else FALSE. This Information Element specifies the initialiser value to the hash function. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 49] Internet-Draft PSAMP Information Model July 2008 Authors' Addresses Thomas Dietz NEC Europe Ltd. NEC Laboratories Europe Network Research Division Kurfuersten-Anlage 36 Heidelberg 69115 Germany Phone: +49 6221 4342-128 Email: Thomas.Dietz@nw.neclab.eu URI: http://www.nw.neclab.eu/ Benoit Claise Cisco Systems, Inc. De Kleetlaan 6a b1 Degem 1813 Belgium Phone: +32 2 704 5622 Email: bclaise@cisco.com Paul Aitken Cisco Systems, Inc. 96 Commercial Quay Edinburgh EH6 6LX Scotland Phone: +44 131 561 3616 Email: paitken@cisco.com URI: http://www.cisco.com/ Falko Dressler University of Erlangen-Nuremberg Dept. of Computer Sciences Martensstr. 3 Erlangen 91058 Germany Phone: +49 9131 85-27914 Email: dressler@informatik.uni-erlangen.de URI: http://www7.informatik.uni-erlangen.de/~dressler Dietz, et al. draft-ietf-psamp-info-09.txt [Page 50] Internet-Draft PSAMP Information Model July 2008 Georg Carle University of Tuebingen Wilhelm-Schickard-Institute for Computer Science Auf der Morgenstelle 10C Tuebingen 71076 Germany Phone: +49 7071 29-70505 Email: carle@informatik.uni-tuebingen.de URI: http://net.informatik.uni-tuebingen.de/~carle/ Dietz, et al. draft-ietf-psamp-info-09.txt [Page 51] Internet-Draft PSAMP Information Model July 2008 Full Copyright Statement Copyright (C) The IETF Trust (2008). 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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. Dietz, et al. draft-ietf-psamp-info-09.txt [Page 52]