Network Working Group T. Graf Internet-Draft Swisscom Intended status: Standards Track B. Claise Expires: 9 January 2023 Huawei A. Huang Feng INSA-Lyon 8 July 2022 Export of Forwarding Path Delay in IPFIX draft-tgraf-opsawg-ipfix-inband-telemetry-00 Abstract This document introduces new IP Flow Information Export (IPFIX) information elements to expose the Inband Telemetry measured forwarding path delay in passport and postcard mode on the transit and decapsulation nodes. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 9 January 2023. Copyright Notice Copyright (c) 2022 IETF Trust and the persons identified as the document authors. All rights reserved. Graf, et al. Expires 9 January 2023 [Page 1] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. IP One-Way Delay Hybrid Type I Passive Registry Entries . . . 4 2.1. Summary . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1.1. ID (Identifier) . . . . . . . . . . . . . . . . . . . 4 2.1.2. Name . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1.3. Name . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1.4. URI . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Description . . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Change Controller . . . . . . . . . . . . . . . . . . . . 5 2.4. Version of Registry Format . . . . . . . . . . . . . . . 5 3. Metric Definition . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Reference Definition . . . . . . . . . . . . . . . . . . 5 3.2. Fixed Parameters . . . . . . . . . . . . . . . . . . . . 6 4. Method of Measurement . . . . . . . . . . . . . . . . . . . . 6 4.1. Reference Methods . . . . . . . . . . . . . . . . . . . . 6 4.2. Packet Stream Generation . . . . . . . . . . . . . . . . 6 4.3. Traffic Filtering (Observation) Details . . . . . . . . . 6 4.4. Sampling Distribution . . . . . . . . . . . . . . . . . . 6 4.5. Runtime Parameters and Data Format . . . . . . . . . . . 7 4.6. Roles . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5. Output . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.1. Type . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.2. Reference Definition . . . . . . . . . . . . . . . . . . 8 5.2.1. Mean . . . . . . . . . . . . . . . . . . . . . . . . 8 5.2.2. Min . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.2.3. Max . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.2.4. Sum . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.2.5. Metric Units . . . . . . . . . . . . . . . . . . . . 10 5.2.6. Calibration . . . . . . . . . . . . . . . . . . . . . 10 5.3. Administrative Items . . . . . . . . . . . . . . . . . . 10 5.3.1. Status . . . . . . . . . . . . . . . . . . . . . . . 10 5.3.2. Requester . . . . . . . . . . . . . . . . . . . . . . 10 5.3.3. Revision . . . . . . . . . . . . . . . . . . . . . . 10 5.3.4. Revision Date . . . . . . . . . . . . . . . . . . . . 11 5.4. Comments and Remarks . . . . . . . . . . . . . . . . . . 11 6. IPFIX Information Elements . . . . . . . . . . . . . . . . . 11 7. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Graf, et al. Expires 9 January 2023 [Page 2] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 8.1. PathDelayMeanDeltaMicroseconds . . . . . . . . . . . . . 13 8.2. PathDelayMeanDeltaNanoseconds . . . . . . . . . . . . . . 14 8.3. PathDelayMinDeltaMicroseconds . . . . . . . . . . . . . . 14 8.4. PathDelayMinDeltaNanoseconds . . . . . . . . . . . . . . 14 8.5. PathDelayMaxDeltaMicroseconds . . . . . . . . . . . . . . 14 8.6. PathDelayMaxDeltaNanoseconds . . . . . . . . . . . . . . 14 8.7. PathDelaySumDeltaMicroseconds . . . . . . . . . . . . . . 14 8.8. PathDelaySumDeltaNanoseconds . . . . . . . . . . . . . . 14 9. Operational Considerations . . . . . . . . . . . . . . . . . 15 9.1. Time Accuracy . . . . . . . . . . . . . . . . . . . . . . 15 9.2. Mean Delay . . . . . . . . . . . . . . . . . . . . . . . 15 9.3. IOAM Packet Time Stamps . . . . . . . . . . . . . . . . . 15 10. Security Considerations . . . . . . . . . . . . . . . . . . . 15 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 15 12.1. Normative References . . . . . . . . . . . . . . . . . . 15 12.2. Informative References . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 18 1. Introduction With Inband Telemetry, defined in In-situ OAM [I-D.ietf-ippm-ioam-deployment], Path Tracing [I-D.filsfils-spring-path-tracing] and In-situ Flow Information Telemetry [I-D.song-opsawg-ifit-framework], the path delay between two endpoints is measured by inserting a timestamp in the packet. Inband Telemetry can be distinguished between two modes. Passport mode where only the last hop in the forwarding path of the Inband Telemetry domain exposes all the metrics and postcard mode where the transit nodes also expose metrics. In both modes the forwarding path is exposed thus allowing to determine how much delay has been accumulated hop by hop. This document defines eight new IPFIX Information Elements (IEs) with their four corresponding entries in the performance metrics registry to expose the forwarding path delay on the transit and decapsulation nodes. The delay is measured by calculating the difference between the timestamp imposed with Inband Telemetry in the packet at the encapsulation node and the timestamp exported in the IPFIX flow record from the transit and decapsulation nodes. Depending on the IE, the lowest, highest or the sum of measured delay is being exported. Graf, et al. Expires 9 January 2023 [Page 3] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 2. IP One-Way Delay Hybrid Type I Passive Registry Entries This section specifies four Registry Entries for the Hybrid Type I Passive assessment of IP One-Way Delay. All column entries besides the ID, Name, Description, and Output Reference Method categories are the same; thus, this section defines four closely related Registry Entries. As a result, IANA has assigned corresponding URLs to each of the four Named Metrics. 2.1. Summary This category includes multiple indexes to the Registry Entry: the element ID and Metric Name. 2.1.1. ID (Identifier) 2.1.2. Name IANA has allocated the numeric Identifiers TBD1-4 for the four Named Metric Entries in this section 2.1.3. Name TBD1: OWDelay_HybridType1_Passive_IP_RFCTBD_Seconds_Mean TBD2: OWDelay_HybridType1_Passive_IP_RFCTBD_Seconds_Min TBD3: OWDelay_HybridType1_Passive_IP_RFCTBD_Seconds_Max TBD4: OWDelay_HybridType1_Passive_IP_RFCTBD_Seconds_Sum 2.1.4. URI URL: https://www.iana.org/assignments/performance-metrics/ OWDelay_HybridType1_Passive_IP_RFCTBD_Seconds_Mean URL: https://www.iana.org/assignments/performance-metrics/ OWDelay_HybridType1_Passive_IP_RFCTBD_Seconds_Min URL: https://www.iana.org/assignments/performance-metrics/ OWDelay_HybridType1_Passive_IP_RFCTBD_Seconds_Max URL: https://www.iana.org/assignments/performance-metrics/ OWDelay_HybridType1_Passive_IP_RFCTBD_Seconds_Sum Graf, et al. Expires 9 January 2023 [Page 4] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 2.2. Description This metric assesses the one-way delay of IP packets constituting a single connection, exchanged between two hosts. We consider the measurement of one-way delay based on a single Observation Point (OP) [RFC7011] somewhere in the network. The output is the one-way delay for all successfully exchanged packets expressed as the of their conditional delay distribution, where is one of: * Mean * Min * Max * Sum 2.3. Change Controller IETF 2.4. Version of Registry Format 1.0 3. Metric Definition This category includes columns to prompt the entry of all necessary details related to the metric definition, including the immutable document reference and values of input factors, called "Fixed Parameters". 3.1. Reference Definition Almes, G., Kalidindi, S., Zekauskas, M., and A. Morton, Ed., "A One- Way Delay Metric for IP Performance Metrics (IPPM)", STD 81, RFC 7679, DOI 10.17487/RFC7679, January 2016, . [RFC7679] Morton, A. and E. Stephan, "Spatial Composition of Metrics", RFC 6049, DOI 10.17487/RFC6049, January 2011, . [RFC6049] Section 3.4 of [RFC7679] provides the reference definition of the singleton (single value) one-way delay metric. Section 4.4 of [RFC7679] provides the reference definition expanded to cover a multi-value sample. Note that terms such as "singleton" and "sample" are defined in section 2 of [RFC2330]. Graf, et al. Expires 9 January 2023 [Page 5] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 With the OP [RFC7011] typically located between the hosts participating in the IP connection, the one-way delay metric requires one individual measurement between the OP and sourcing host, such that the Spatial Composition [RFC6049] of the measurements yields a one-way delay singleton. 3.2. Fixed Parameters Traffic Filters: IPv4 header values: DSCP: Set to 0 IPv6 header values: DSCP: Set to 0 Hop Count: Set to 255 Flow Label: Set to 0 Extension Headers: None 4. Method of Measurement This category includes columns for references to relevant sections of the RFC(s) and any supplemental information needed to ensure an unambiguous method for implementations. 4.1. Reference Methods The foundational methodology for this metric is defined in section 4 of [RFC7323] using the Timestamps option with modifications that allow application at a mid-path OP [RFC7011]. The Traffic Filter at the OP is configured to observe a single IP connection. 4.2. Packet Stream Generation N/A 4.3. Traffic Filtering (Observation) Details The Fixed Parameters above give a portion of the Traffic Filter. Other aspects will be supplied as Runtime Parameters (below). 4.4. Sampling Distribution This metric requires a partial sample of all packets that qualify according to the Traffic Filter criteria. Graf, et al. Expires 9 January 2023 [Page 6] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 4.5. Runtime Parameters and Data Format Runtime Parameters are input factors that must be determined, configured into the measurement system, and reported with the results for the context to be complete. Src: The IP address of the host in the host A Role (format ipv4-address-no-zone value for IPv4 or ipv6-address-no-zone value for IPv6; see section 4 of [RFC6991]. Dst: The IP address of the host in the host B Role (format ipv4-address-no-zone value for IPv4 or ipv6-address-no-zone value for IPv6; see section 4 of [RFC6991]. TTL or Hop Limit: Set at desired value. DSCP: Set at desired value. IPv6 Flow Label: Set at desired value. Timestamp: The timestamp when the packet is being received at IOAM encapsulation node. Format depends on Inband Telemetry implementation. For IOAM, Section 4.4.1 of [RFC9197] describes what kind of timestamps are supported. Section 4.4.2.3 and 4.4.2.4 describe where the timestamp is being inserted. For Path Tracing, Section 4.1 of [I-D.filsfils-spring-path-tracing] describes what kind of timestamps are supported. Section 9.2 describe the SRH path tracing TLV where the timestamp is being inserted. 4.6. Roles host A: Launches the IP packet to open the connection. The Role of "host A" is synonymous with the IP address used at host A. host B: Receives the IP packet to open the connection. The Role of "host B" is synonymous with the IP address used at host B. Encapsulation Node: Receives the IP packet to open the connection and encapsulates the timestamp into the packet. The Role of "Encapsulation Node" is synonymous with the timestamp inserted in the packet. Transit Node: Receives the IP packet to open the connection and measures the delay between the timestamp in the packet and the timestamp when the packet was received. Decapsulation Node: Receives the IP packet to open the connection Graf, et al. Expires 9 January 2023 [Page 7] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 and measures the delay between the timestamp in the packet and the timestamp when the packet was received and removes the IOAM header from the packet. 5. Output This category specifies all details of the output of measurements using the metric. 5.1. Type OWDelay Types are discussed in the subsections below. 5.2. Reference Definition For all output types: OWDelay_HybridType1_Passive_IP: The one-trip delay of one IP packet is a Singleton For each , Singleton one of the following subsections applies. 5.2.1. Mean The mean SHALL be calculated using the conditional distribution of all packets with a finite value of one-way delay (undefined delays are excluded) -- a single value, as follows: See section 4.1 of [RFC3393] for details on the conditional distribution to exclude undefined values of delay, and see section 5 of [RFC6703] for background on this analysis choice. See section 4.2.2 of [RFC6049] for details on calculating this statistic; see also section 4.2.3 of [RFC6049]. Mean: The time value of the result is expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 9 (see section 9.3 of [RFC6020]) with a resolution of 0.000000001 seconds (1.0 ns), and with lossless conversion to/from the 64-bit NTP timestamp as per section 6 of [RFC5905]. 5.2.2. Min The minimum SHALL be calculated using the conditional distribution of all packets with a finite value of one-way delay (undefined delays are excluded) -- a single value, as follows: Graf, et al. Expires 9 January 2023 [Page 8] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 See section 4.1 of [RFC3393] for details on the conditional distribution to exclude undefined values of delay, and see section 5 of [RFC6703] for background on this analysis choice. See section 4.3.2 of [RFC6049] for details on calculating this statistic; see also section 4.3.3 of [RFC6049]. Min: The time value of the result is expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 9 (see section 9.3 of [RFC6020]) with a resolution of 0.000000001 seconds (1.0 ns), and with lossless conversion to/from the 64-bit NTP timestamp as per section 6 of [RFC5905]. 5.2.3. Max The maximum SHALL be calculated using the conditional distribution of all packets with a finite value of one-way delay (undefined delays are excluded) -- a single value, as follows: See section 4.1 of [RFC3393] for details on the conditional distribution to exclude undefined values of delay, and see section 5 of [RFC6703] for background on this analysis choice. See section 4.3.2 of [RFC6049] for a closely related method for calculating this statistic; see also section 4.3.3 of [RFC6049]. The formula is as follows: Max = (FiniteDelay[j]) such that for some index, j, where 1 <= j <= N FiniteDelay[j] >= FiniteDelay[n] for all n Max: The time value of the result is expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 9 (see section 9.3 of [RFC6020]) with a resolution of 0.000000001 seconds (1.0 ns), and with lossless conversion to/from the 64-bit NTP timestamp as per section 6 of [RFC5905]. 5.2.4. Sum The sum SHALL be calculated using the conditional distribution of all packets with a finite value of one-way delay (undefined delays are excluded) -- a single value, as follows: See section 4.1 of [RFC3393] for details on the conditional distribution to exclude undefined values of delay, and see section 5 of [RFC6703] for background on this analysis choice. Graf, et al. Expires 9 January 2023 [Page 9] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 See section 4.3.5 of [RFC6049] for details on calculating this statistic. However in this case FiniteDelay or MaxDelay MAY be used. Sum: The time value of the result is expressed in units of seconds, as a positive value of type decimal64 with fraction digits = 9 (see section 9.3 of [RFC6020]) with a resolution of 0.000000001 seconds (1.0 ns), and with lossless conversion to/from the 64-bit NTP timestamp as per section 6 of [RFC5905]. 5.2.5. Metric Units The of one-way delay is expressed in seconds, where is one of: * Mean * Min * Max * Sum The one-way delay of the IP connection singleton is expressed in seconds. 5.2.6. Calibration Passive Measurements at an OP could be calibrated against an Active Measurement at host A where the Active Measurement represents the ground truth. 5.3. Administrative Items 5.3.1. Status Current 5.3.2. Requester This RFC 5.3.3. Revision 1.0 Graf, et al. Expires 9 January 2023 [Page 10] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 5.3.4. Revision Date RFC Date 5.4. Comments and Remarks None 6. IPFIX Information Elements This section defines and describes the new IPFIX IEs. PathDelayMeanDeltaMicroseconds 16-bit unsigned integer that identifies the mean path delay. PathDelayMeanDeltaNanoseconds 32-bit unsigned integer that identifies the mean path delay. PathDelayMinDeltaMicroseconds 16-bit unsigned integer that identifies the lowest path delay. PathDelayMinDeltaNanoseconds 32-bit unsigned integer that identifies the lowest path delay. PathDelayMaxDeltaMicroseconds 16-bit unsigned integer that identifies the highest path delay. PathDelayMaxDeltaNanoseconds 32-bit unsigned integer that identifies the highest path delay. PathDelaySumDeltaMicroseconds 32-bit unsigned integer that identifies the sum of the path delay. PathDelaySumDeltaNanoseconds 64-bit unsigned integer that identifies the sum of the path delay. 7. Use Cases The measured forwarding path delay can be aggregated with Flow Aggregation as defined in [RFC7015] to the following device and control-plane dimensions to determine: * With node id and egressInterface(IE14), on which node which logical egress interfaces have been contributing to how much delay. Graf, et al. Expires 9 January 2023 [Page 11] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 * With node id and egressPhysicalInterface(253), on which node which physical egress interfaces have been contributing to how much delay. * With ipNextHopIPv4Address(IE15) or ipNextHopIPv6Address(IE62), the forwarding path to which next-hop IP contributed to how much delay. * With mplsTopLabelIPv4Address(IE47) or srhActiveSegmentIPv6 from [I-D.tgraf-opsawg-ipfix-srv6-srh], the forwarding path to which MPLS top label IPv4 address or SRv6 active segment contributed to how much delay. * BGP communities are often used for setting a path priority or service selection. With bgpDestinationExtendedCommunityList(488) or bgpDestinationCommunityList(485) or bgpDestinationLargeCommunityList(491) which group of prefixes accumulated at which node how much delay. * With destinationIPv4Address(13), destinationTransportPort(11), protocolIdentifier (4) and sourceIPv4Address(IE8), the forwarding path delay on each node from each IPv4 source address to a specific application in the network. 8. IANA Considerations This document requests IANA to create new IEs (see table 1) and assign the following initial code points. Graf, et al. Expires 9 January 2023 [Page 12] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 +-------+--------------------------------+ |Element| Name | | ID | | +-------+--------------------------------+ | TBD5 | PathDelayMeanDeltaMicroseconds | | | | +-------+--------------------------------+ | TBD6 | PathDelayMeanDeltaNanoseconds | | | | +-------+--------------------------------+ | TBD7 | PathDelayMinDeltaMicroseconds | | | | +-------+--------------------------------+ | TBD8 | PathDelayMinDeltaNanoseconds | | | | +-------+--------------------------------+ | TBD9 | PathDelayMaxDeltaMicroseconds | | | | +-------+--------------------------------+ | TBD10 | PathDelayMaxDeltaNanoseconds | | | | +-------+--------------------------------+ | TBD11 | PathDelaySumDeltaMicroseconds | | | | +-------+--------------------------------+ | TBD12 | PathDelaySumDeltaNanoseconds | | | | +-------+--------------------------------+ Table 1: Creates IEs in the "IPFIX Information Elements" registry Note to the RFC-Editor: * Please replace TBD5 - TBD12 with the values allocated by IANA * Please replace the [RFC-to-be] with the RFC number assigned to this document 8.1. PathDelayMeanDeltaMicroseconds Name: PathDelayMeanDeltaMicroseconds ElementID: TBD5 Description: This Information Element identifies the mean path delay in microseconds. Abstract Data Type: unsigned16 Data Type Semantics: OctedDelta Reference: [RFC-to-be], xxx Graf, et al. Expires 9 January 2023 [Page 13] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 8.2. PathDelayMeanDeltaNanoseconds Name: PathDelayMeanDeltaNanoseconds ElementID: TBD6 Description: This Information Element identifies the mean path delay in nanoseconds. Abstract Data Type: unsigned32 Data Type Semantics: OctedDelta Reference: [RFC-to-be], xxx 8.3. PathDelayMinDeltaMicroseconds Name: PathDelayMinDeltaMicroseconds ElementID: TBD7 Description: This Information Element identifies the lowest path delay in microseconds. Abstract Data Type: unsigned16 Data Type Semantics: OctedDelta Reference: [RFC-to-be], xxx 8.4. PathDelayMinDeltaNanoseconds Name: PathDelayMinDeltaNanoseconds ElementID: TBD8 Description: This Information Element identifies the lowest path delay in nanoseconds. Abstract Data Type: unsigned32 Data Type Semantics: OctedDelta Reference: [RFC-to-be], xxx 8.5. PathDelayMaxDeltaMicroseconds Name: PathDelayMaxDeltaMicroseconds ElementID: TBD9 Description: This Information Element identifies the highest path delay in microseconds. Abstract Data Type: unsigned16 Data Type Semantics: OctedDelta Reference: [RFC-to-be], xxx 8.6. PathDelayMaxDeltaNanoseconds Name: PathDelayMaxDeltaNanoseconds ElementID: TBD10 Description: This Information Element identifies the highest path delay in nanoseconds. Abstract Data Type: unsigned32 Data Type Semantics: OctedDelta Reference: [RFC-to-be], xxx 8.7. PathDelaySumDeltaMicroseconds Name: PathDelaySumDeltaMicroseconds ElementID: TBD11 Description: This Information Element identifies the sum of the path delay in microseconds. Abstract Data Type: unsigned32 Data Type Semantics: OctedDelta Reference: [RFC-to-be], xxx 8.8. PathDelaySumDeltaNanoseconds Name: PathDelaySumDeltaNanoseconds ElementID: TBD12 Description: This Information Element identifies the sum of the path delay in nanoseconds. Abstract Data Type: unsigned64 Data Type Semantics: OctedDelta Reference: [RFC-to-be], xxx Graf, et al. Expires 9 January 2023 [Page 14] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 9. Operational Considerations 9.1. Time Accuracy The same recommendation as defined in section 4.5 of [RFC5153] for IPFIX applies in terms of clock precision to this document as well. 9.2. Mean Delay The mean (average) path delay can be calculated by dividing the PathDelaySumDeltaMicroseconds(TBD5) or PathDelaySumDeltaNanoseconds(TBD6) by the packetDeltaCount(2) at the IPFIX data collection. 9.3. IOAM Packet Time Stamps For IOAM, Section 4.4.1 of [RFC9197] describes what kind of timestamps are supported. Section 4.4.2.3 and 4.4.2.4 describe where the timestamp is being inserted. For Path Tracing, Section 4.1 of [I-D.filsfils-spring-path-tracing] describes what kind of timestamps are supported. Section 9.2 describe the SRH path tracing TLV where the timestamp is being inserted. 10. Security Considerations There are no significant extra security considerations regarding the allocation of these new IPFIX IEs compared to [RFC7012]. 11. Acknowledgements The authors would like to thank xxx for their review and valuable comments. 12. References 12.1. Normative References [RFC7012] Claise, B., Ed. and B. Trammell, Ed., "Information Model for IP Flow Information Export (IPFIX)", RFC 7012, DOI 10.17487/RFC7012, September 2013, . 12.2. Informative References Graf, et al. Expires 9 January 2023 [Page 15] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 [I-D.filsfils-spring-path-tracing] Filsfils, C., Abdelsalam, A., Garvia, P. C., Yufit, M., Graf, T., Su, Y., Matsushima, S., and M. Valentine, "Path Tracing in SRv6 networks", Work in Progress, Internet- Draft, draft-filsfils-spring-path-tracing-01, 30 May 2022, . [I-D.ietf-ippm-ioam-deployment] Brockners, F., Bhandari, S., Bernier, D., and T. Mizrahi, "In-situ OAM Deployment", Work in Progress, Internet- Draft, draft-ietf-ippm-ioam-deployment-01, 11 April 2022, . [I-D.song-opsawg-ifit-framework] Song, H., Qin, F., Chen, H., Jin, J., and J. Shin, "A Framework for In-situ Flow Information Telemetry", Work in Progress, Internet-Draft, draft-song-opsawg-ifit- framework-17, 22 February 2022, . [I-D.tgraf-opsawg-ipfix-srv6-srh] Graf, T., Claise, B., and P. Francois, "Export of Segment Routing IPv6 Information in IP Flow Information Export (IPFIX)", Work in Progress, Internet-Draft, draft-tgraf- opsawg-ipfix-srv6-srh-04, 28 June 2022, . [RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, "Framework for IP Performance Metrics", RFC 2330, DOI 10.17487/RFC2330, May 1998, . [RFC3393] Demichelis, C. and P. Chimento, "IP Packet Delay Variation Metric for IP Performance Metrics (IPPM)", RFC 3393, DOI 10.17487/RFC3393, November 2002, . [RFC5153] Boschi, E., Mark, L., Quittek, J., Stiemerling, M., and P. Aitken, "IP Flow Information Export (IPFIX) Implementation Guidelines", RFC 5153, DOI 10.17487/RFC5153, April 2008, . Graf, et al. Expires 9 January 2023 [Page 16] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [RFC6049] Morton, A. and E. Stephan, "Spatial Composition of Metrics", RFC 6049, DOI 10.17487/RFC6049, January 2011, . [RFC6703] Morton, A., Ramachandran, G., and G. Maguluri, "Reporting IP Network Performance Metrics: Different Points of View", RFC 6703, DOI 10.17487/RFC6703, August 2012, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . [RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken, "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information", STD 77, RFC 7011, DOI 10.17487/RFC7011, September 2013, . [RFC7015] Trammell, B., Wagner, A., and B. Claise, "Flow Aggregation for the IP Flow Information Export (IPFIX) Protocol", RFC 7015, DOI 10.17487/RFC7015, September 2013, . [RFC7323] Borman, D., Braden, B., Jacobson, V., and R. Scheffenegger, Ed., "TCP Extensions for High Performance", RFC 7323, DOI 10.17487/RFC7323, September 2014, . [RFC7679] Almes, G., Kalidindi, S., Zekauskas, M., and A. Morton, Ed., "A One-Way Delay Metric for IP Performance Metrics (IPPM)", STD 81, RFC 7679, DOI 10.17487/RFC7679, January 2016, . [RFC9197] Brockners, F., Ed., Bhandari, S., Ed., and T. Mizrahi, Ed., "Data Fields for In Situ Operations, Administration, and Maintenance (IOAM)", RFC 9197, DOI 10.17487/RFC9197, May 2022, . Graf, et al. Expires 9 January 2023 [Page 17] Internet-Draft Export of Forwarding Path Delay in IPFIX July 2022 Authors' Addresses Thomas Graf Swisscom Binzring 17 CH-8045 Zurich Switzerland Email: thomas.graf@swisscom.com Benoit Claise Huawei Email: benoit.claise@huawei.com Alex Huang Feng INSA-Lyon Lyon France Email: alex.huang-feng@insa-lyon.fr Graf, et al. Expires 9 January 2023 [Page 18]