IPFIX Working Group E. Boschi Internet-Draft Hitachi Europe Intended status: Standards Track B. Trammell Expires: December 29, 2007 CERT/NetSA L. Mark T. Zseby Fraunhofer FOKUS June 27, 2007 Extended Type Information for IPFIX Enterprise-Specific Information Elements draft-boschi-ipfix-extended-type-00.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on December 29, 2007. Copyright Notice Copyright (C) The IETF Trust (2007). Abstract This document describes an extension to IPFIX to provide type information for enterprise-specific Information Elements. This format is designed to facilitate interoperability and reusability Boschi, et al. Expires December 29, 2007 [Page 1] Internet-Draft IPFIX Extended Type Information June 2007 among a wide variety of applications and tools. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Type Information Extension . . . . . . . . . . . . . . . . . . 3 3.1. informationElementId . . . . . . . . . . . . . . . . . . . 4 3.2. informationElementSemanticType . . . . . . . . . . . . . . 4 3.3. informationElementStorageType . . . . . . . . . . . . . . 5 3.4. privateEnterpriseNumber . . . . . . . . . . . . . . . . . 6 3.5. Information Element Semantics Options Template . . . . . . 7 4. Security Considerations . . . . . . . . . . . . . . . . . . . 8 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 7.1. Normative References . . . . . . . . . . . . . . . . . . . 9 7.2. Informative References . . . . . . . . . . . . . . . . . . 9 Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 10 Appendix B. XML Specification of Extended Type Information Elements . . . . . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 Intellectual Property and Copyright Statements . . . . . . . . . . 17 Boschi, et al. Expires December 29, 2007 [Page 2] Internet-Draft IPFIX Extended Type Information June 2007 1. Introduction The IPFIX protocol specification allows the creation of enterprise- specific Information Elements to easily extend the protocol to meet requirements which aren't covered by the existing Information Model. However, there is no current mechanism to provide the data type for a given Information Element (e.g. enterprise-specific ones). In this situation, it will not be possible to use any existing analysis tool on IPFIX records containing enterprise-specific Information Elements, since the tools will not be able to decode these Information Elements. Having to do some sort of tool-specific configuration (or code modification) on every tool just to tell which type each used Information Element has is a huge amount of work for users and implementors of enterprise-specific Information Eelements. Many tools in fact only need to know the field's data type to work on them. This memo specifies a mechanism for users to provide the data type of an Information Elements in a standardized, automatable way. This memo specifies a mechanism for exporters to provide the data type and semantic information of enterprise-specific Information Elements within the exported data stream in a standardized and automatable way. We propose a mechanism, which makes use of IPFIX Options Records to allow the mapping from (enterpriseID,Information Element) pairs to corresponding data type and semantic information. Including the information inline allows more rapid processing of the data, and allows the flow stream (or file) to be partially self- describing. 2. Terminology Terms used in this document that are defined in the Terminology section of the IPFIX Protocol [I-D.ietf-ipfix-protocol] document are to be interpreted as defined there. 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]. 3. Type Information Extension IPFIX Templates contain ID and length values but lack type and semantic information. There is no standard method to get this information for enterprise-specific Information Elements. A Collecting Process receiving data described by a Template containing unknown enterprise-specific Information Elements can only treat those Boschi, et al. Expires December 29, 2007 [Page 3] Internet-Draft IPFIX Extended Type Information June 2007 data as octet arrays. To be fully self-describing, enterprise- specific Information Elements must be additionally described via IPFIX Options according to the Information Element Semantics Options Template defined below. In this section we first specify the necessary Information Elements for describing type information, and then the Information Element Semantics Options Template. 3.1. informationElementId Description: An information element ID, as would appear in an IPFIX Template Record. This element can be used to scope properties to a specific information element within a Template. This IE should be encoded with the Enterprise ID bit set to 0, regardless of whether the Enterprise ID bit is set in the template to which this IE refers. See the definition of privateEnterpriseNumber below for more on the use of this IE to describe vendor-specific IEs. Abstract Data Type: unsigned16 Data Type Semantics: identifier ElementId: TBD1 Status: Proposed Reference: Section 3.4.1 of the IPFIX Protocol draft 3.2. informationElementSemanticType Description: A description of the semantics of an IPFIX information element within a template. These correspond to the data type semantics defined in section 3.2 of the IPFIX Information Model [I-D.ietf-ipfix-info]; see that section for more information on the types described below. This field may take the following values; the special value 0x00 (none) is used to note that no semantics apply to the field; it cannot be manipulated by a Collecting Process or File Reader that does not understand it a priori. Boschi, et al. Expires December 29, 2007 [Page 4] Internet-Draft IPFIX Extended Type Information June 2007 +-------+--------------+ | Value | Description | +-------+--------------+ | 0x00 | none | | 0x01 | quantity | | 0x02 | totalCounter | | 0x03 | deltaCounter | | 0x04 | identifier | | 0x05 | flags | +-------+--------------+ Abstract Data Type: unsigned8 ElementId: TBD2 Status: Proposed 3.3. informationElementStorageType Description: A description of the storage type of an IPFIX information element within a template. These correspond to the abstract data types defined in section 3.1 of the IPFIX Information Model [I-D.ietf-ipfix-info]; see that section for more information on the types described below. This field may take the following values: Boschi, et al. Expires December 29, 2007 [Page 5] Internet-Draft IPFIX Extended Type Information June 2007 +-------+----------------------+ | Value | Description | +-------+----------------------+ | 0x00 | octetArray | | 0x01 | unsigned8 | | 0x02 | unsigned16 | | 0x03 | unsigned32 | | 0x04 | unsigned64 | | 0x05 | signed8 | | 0x06 | signed16 | | 0x07 | signed32 | | 0x08 | signed64 | | 0x09 | float32 | | 0x0A | float64 | | 0x0B | boolean | | 0x0C | macAddress | | 0x0D | string | | 0x0E | dateTimeSeconds | | 0x0F | dateTimeMilliseconds | | 0x10 | dateTimeMicroseconds | | 0x11 | dateTimeNanoseconds | | 0x12 | ipv4Address | | 0x13 | ipv6Address | +-------+----------------------+ Abstract Data Type: unsigned8 ElementId: TBD3 Status: Proposed Reference: Section 3.1 of the IPFIX Information Model 3.4. privateEnterpriseNumber Description: A private enterprise number used to scope an information element ID, as would appear in an IPFIX Template Record. This element can be used to scope properties to a specific information element within a Template. If the Enterprise ID bit of the corresponding Information Element is cleared (has the value 0), this IE should be set to 0. The presence of a non- zero value in this IE implies that the Enterprise ID bit of the corresponding Information Element is set (has the value 1). Abstract Data Type: unsigned32 Boschi, et al. Expires December 29, 2007 [Page 6] Internet-Draft IPFIX Extended Type Information June 2007 Data Type Semantics: identifier ElementId: TBD4 Status: Proposed Reference: Section 3.4.1 of the IPFIX Protocol draft 3.5. Information Element Semantics Options Template The Information Element Semantics Options Template specifies the structure of a Data Record for attaching semantic and storage type information to Enterprise Specific Information Elements in specified Template Records. Data Records described by this template are referred to as Information Element semantics records. In deployments in which interoperability across vendor implementations of IPFIX is important, an Exporting Process exporting data using Templates containing enterprise-specific Information Elements SHOULD export an Information Element semantics record for each enterprise-specific Information Element it exports. Collecting Processes MAY use these semantics records to improve handling of unknown enterprise-specific Information Elements. Exporting Processes using enterprise-specific Information Elements to implement proprietary features MAY omit semantics records for those Information ELements. Information Element semantics records MUST be handled by Collecting Processes as scoped to the Transport Session in which they are sent; this facility is not intended to provide a method for the permanent definition of Information Elements. Similarly, for security reasons, storage and semantics types for a given Information Element MUST NOT be re-defined by Information Element semantics records. Once an Information Element semantics record has been exported for a given Information Element within a given Transport Session, all subsequent semantics records for that Information Element MUST be identical. If conflicting semantic or type information is received in multiple semantics records by a Collecting Process, the Collecting Process MUST reset the Transport Session. Information Element semantics records MUST NOT be used to define semantics for IANA registered Information Elements (private enterprise number (PEN) 0) or for PENs with a special meaning within the IPFIX Protocol (e.g., the Reverse PEN from Bidirectional Flow Export using IPFIX [I-D.ietf-ipfix-biflow]). Boschi, et al. Expires December 29, 2007 [Page 7] Internet-Draft IPFIX Extended Type Information June 2007 The template SHOULD contain the following Information Elements as defined in the IPFIX Information Model [I-D.ietf-ipfix-info] and above: +--------------------------------+----------------------------------+ | IE | Description | +--------------------------------+----------------------------------+ | informationElementID | The Information Element | | | identifier of the Information | | | Element within the specified | | | Template this record describes. | | | This Information Element MUST be | | | defined as a Scope Field. | | privateEnterpriseNumber | The Private Enterprise number of | | | the Information Element within | | | the specified Template this | | | record describes. This | | | Information Element MUST be | | | defined as a Scope Field. | | informationElementStorageType | The storage type of the | | | specified Information Element. | | informationElementSemanticType | The semantic type of the | | | specified Information Element. | +--------------------------------+----------------------------------+ 4. Security Considerations The same security considerations as for the IPFIX Protocol [I-D.ietf-ipfix-protocol] apply. 5. IANA Considerations This document specifies the creation of four new IPFIX Information Elements as described in sections 4.1 through 4.4. IANA has assigned the IPFIX Information Element number TBD1 in the IPFIX Information Element registry for the informationElementId Information Element; the IPFIX Information Element number TBD2 in the IPFIX Information Element registry for the informationElementSemanticType Information Element; the IPFIX Information Element number TBD3 in the IPFIX Information Element registry for the informationElementStorageType Information Element; and the IPFIX Information Element number TBD4 in the IPFIX Information Element registry for the privateEnterpriseNumber Information Element. [NOTE for IANA: The text TBD1 should be replaced with the assigned informationElementId Information Element number where it appears in Boschi, et al. Expires December 29, 2007 [Page 8] Internet-Draft IPFIX Extended Type Information June 2007 this document. The text TBD2 should be replaced with the assigned informationElementSemanticType Information Element number where it appears in this document. The text TBD3 should be replaced with the assigned informationElementStorageType Information Element number where it appears in this document. The text TBD4 should be replaced with the assigned privateEnterpriseNumber Information Element number where it appears in this document.] In addition, IANA has created an Information Element Semantic Type subregistry for the values defined for the informationElementSemanticType Information Element in section 4.2. A specification is required to add entries to this subregistry; new values and their meaning must be documented in an RFC or other permanent and readily available reference. [NOTE for IANA: Please create a new Information Element Semantic Type subregistry as specified in the paragraph above, with initial values taken from section 4.2 of this document.] 6. Acknowledgements Thanks to David Moore for first raising this issue to the IPFIX mailing list. 7. References 7.1. Normative References [I-D.ietf-ipfix-protocol] Claise, B., "Specification of the IPFIX Protocol for the Exchange", draft-ietf-ipfix-protocol-24 (work in progress), November 2006. [I-D.ietf-ipfix-info] Quittek, J., "Information Model for IP Flow Information Export", draft-ietf-ipfix-info-15 (work in progress), February 2007. 7.2. Informative References [I-D.ietf-ipfix-biflow] Trammell, B. and E. Boschi, "Bidirectional Flow Export using IPFIX", draft-ietf-ipfix-biflow-05 (work in progress), June 2007. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Boschi, et al. Expires December 29, 2007 [Page 9] Internet-Draft IPFIX Extended Type Information June 2007 Requirement Levels", BCP 14, RFC 2119, March 1997. Appendix A. Examples The following example illustrates how the type information extension mechanism defined in this document may be used to describe the semantics of enterprise-specific Information Elements. The Information Elements used in this example are as follows: o initialTCPFlags, CERT (PEN 6871) private IE 14, 1 octet, the TCP flags on the first TCP packet in the flow. o unionTCPFlags, CERT (PEN 6871) private IE 15, 1 octet, the union of the TCP flags on all packets after the first TCP packet in the flow. An Exporting Process exporting flows containing these Information Elements might use a Template like the following: Boschi, et al. Expires December 29, 2007 [Page 10] Internet-Draft IPFIX Extended Type Information June 2007 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 2 | Length = 52 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 256 | Field Count = 9 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| flowStartSeconds 150 | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| sourceIPv4Address 8 | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| destinationIPv4Address 12 | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| sourceTransportPort 7 | Field Length = 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| destinationTransportPort 11 | Field Length = 2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| octetTotalCount 85 | Field Length = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| (initialTCPFlags) 14 | Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PEN 6871 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| (unionTCPFlags) 15 | Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PEN 6871 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| protocolIdentifier 4 | Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: Template with Enterprise-Specific IEs However, a Collecting Process receiving Data Sets described by this Template can only treat the enterprise-specific Information Elements as opaque octets; specifically, there is no hint to the collector that they contain flag informartion. To use the type information extension mechanism to address this problem, the Exporting Process would first export the Information Element Semantics Options Template described in section 4.5, above: Boschi, et al. Expires December 29, 2007 [Page 11] Internet-Draft IPFIX Extended Type Information June 2007 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 3 | Length = 26 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Template ID = 257 | Field Count = 4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Scope Field Count = 2 |0| priv.EnterpriseNumber TBD4 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 4 |0| informationElementId TBD1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 2 |0| inf.El.StorageType TBD3 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 1 |0| inf.El.SemanticType TBD2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Field Length = 1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2: Example Information Element Semantics Options Template Then, the Exporting Process would then export two records described by the Example Information Element Semantics Options Template to describe the enterprise-specific Information Elements: 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Set ID = 257 | Length = 20 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PEN 6871 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IE 14 |0x01 unsigned8 |0x05 flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PEN 6871 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IE 15 |0x01 unsigned8 |0x05 flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Type Information Extension Example Appendix B. XML Specification of Extended Type Information Elements This appendix contains a machine-readable description of the Information Elements defined in this document, coded in XML. Note that this appendix is of informational nature, while the text in section 3 is normative. Boschi, et al. Expires December 29, 2007 [Page 12] Internet-Draft IPFIX Extended Type Information June 2007 The format in which this specification is given is described by the XML Schema in Appendix B of the IPFIX Information Model [I-D.ietf-ipfix-info]. An information element ID, as would appear in an IPFIX Template Record. This element can be used to scope properties to a specific information element within a Template. This IE should be encoded with the Enterprise ID bit set to 0, regardless of whether the Enterprise ID bit is set in the template to which this IE refers. See the definition of privateEnterpriseNumber below for more on the use of this IE to describe vendor-specific IEs. A description of the semantics of an IPFIX information element within a template. These correspond to the data type semantics defined in section 3.2 of the IPFIX Information Model; see that section for more information on the types described below. This field may take the following values; the special value 0x00 (none) is used to note that no semantics apply to the field; it cannot be manipulated by a Collecting Process or File Reader that does not understand it a priori. +-------+--------------+ | Value | Description | +-------+--------------+ | 0x00 | none | | 0x01 | quantity | | 0x02 | totalCounter | Boschi, et al. Expires December 29, 2007 [Page 13] Internet-Draft IPFIX Extended Type Information June 2007 | 0x03 | deltaCounter | | 0x04 | identifier | | 0x05 | flags | +-------+--------------+ A description of the storage type of an IPFIX information element within a template. These correspond to the abstract data types defined in section 3.1 of the IPFIX Information Model; see that section for more information on the types described below. This field may take the following values: +-------+----------------------+ | Value | Description | +-------+----------------------+ | 0x00 | octetArray | | 0x01 | unsigned8 | | 0x02 | unsigned16 | | 0x03 | unsigned32 | | 0x04 | unsigned64 | | 0x05 | signed8 | | 0x06 | signed16 | | 0x07 | signed32 | | 0x08 | signed64 | | 0x09 | float32 | | 0x0A | float64 | | 0x0B | boolean | | 0x0C | macAddress | | 0x0D | string | | 0x0E | dateTimeSeconds | | 0x0F | dateTimeMilliseconds | | 0x10 | dateTimeMicroseconds | | 0x11 | dateTimeNanoseconds | | 0x12 | ipv4Address | | 0x13 | ipv6Address | +-------+----------------------+ Boschi, et al. Expires December 29, 2007 [Page 14] Internet-Draft IPFIX Extended Type Information June 2007 A private enterprise number used to scope an information element ID, as would appear in an IPFIX Template Record. This element can be used to scope properties to a specific information element within a Template. If the Enterprise ID bit of the corresponding Information Element is cleared (has the value 0), this IE should be set to 0. The presence of a non-zero value in this IE implies that the Enterprise ID bit of the corresponding Information Element is set (has the value 1). Authors' Addresses Elisa Boschi Hitachi Europe SAS Immeuble Le Theleme 1503 Route les Dolines 06560 Valbonne France Phone: +33 4 89874100 Email: elisa.boschi@hitachi-eu.com Brian H. Trammell CERT Network Situational Awareness Software Engineering Institute 4500 Fifth Avenue Pittsburgh, Pennsylvania 15213 United States Phone: +1 412 268 9748 Email: bht@cert.org Boschi, et al. Expires December 29, 2007 [Page 15] Internet-Draft IPFIX Extended Type Information June 2007 Lutz Mark Fraunhofer Institute for Open Communication Systems Kaiserin-Augusta-Allee 31 10589 Berlin Germany Phone: +49 30 3463 7306 Email: lutz.mark@fokus.fraunhofer.de Tanja Zseby Fraunhofer Institute for Open Communication Systems Kaiserin-Augusta-Allee 31 10589 Berlin Germany Phone: +49 30 3463 7153 Email: tanja.zseby@fokus.fraunhofer.de Boschi, et al. Expires December 29, 2007 [Page 16] Internet-Draft IPFIX Extended Type Information June 2007 Full Copyright Statement Copyright (C) The IETF Trust (2007). 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. Acknowledgment Funding for the RFC Editor function is provided by the IETF Administrative Support Activity (IASA). Boschi, et al. Expires December 29, 2007 [Page 17]