| < draft-fioccola-rfc8889bis-00.txt | draft-fioccola-rfc8889bis-01.txt > | |||
|---|---|---|---|---|
| Network Working Group G. Fioccola, Ed. | Network Working Group G. Fioccola, Ed. | |||
| Internet-Draft Huawei Technologies | Internet-Draft Huawei Technologies | |||
| Obsoletes: 8889 (if approved) M. Cociglio | Obsoletes: 8889 (if approved) M. Cociglio | |||
| Intended status: Standards Track Telecom Italia | Intended status: Standards Track Telecom Italia | |||
| Expires: May 23, 2022 A. Sapio | Expires: June 12, 2022 A. Sapio | |||
| Intel Corporation | Intel Corporation | |||
| R. Sisto | R. Sisto | |||
| Politecnico di Torino | Politecnico di Torino | |||
| November 19, 2021 | T. Zhou | |||
| Huawei Technologies | ||||
| December 9, 2021 | ||||
| Multipoint Alternate-Marking Method | Multipoint Alternate-Marking Method | |||
| draft-fioccola-rfc8889bis-00 | draft-fioccola-rfc8889bis-01 | |||
| Abstract | Abstract | |||
| This document generalizes and expands Alternate-Marking methodology | This document generalizes and expands Alternate-Marking methodology | |||
| to measure any kind of unicast flow whose packets can follow several | to measure any kind of unicast flow whose packets can follow several | |||
| different paths in the network -- in wider terms, a multipoint-to- | different paths in the network -- in wider terms, a multipoint-to- | |||
| multipoint network. For this reason, the technique here described is | multipoint network. For this reason, the technique here described is | |||
| called "Multipoint Alternate Marking". This document obsoletes | called "Multipoint Alternate Marking". This document obsoletes | |||
| [RFC8889]. | [RFC8889]. | |||
| skipping to change at page 1, line 40 ¶ | skipping to change at page 1, line 42 ¶ | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at https://datatracker.ietf.org/drafts/current/. | Drafts is at https://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on May 23, 2022. | This Internet-Draft will expire on June 12, 2022. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2021 IETF Trust and the persons identified as the | Copyright (c) 2021 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (https://trustee.ietf.org/license-info) in effect on the date of | (https://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| carefully, as they describe your rights and restrictions with respect | carefully, as they describe your rights and restrictions with respect | |||
| to this document. Code Components extracted from this document must | to this document. Code Components extracted from this document must | |||
| include Simplified BSD License text as described in Section 4.e of | include Simplified BSD License text as described in Section 4.e of | |||
| the Trust Legal Provisions and are provided without warranty as | the Trust Legal Provisions and are provided without warranty as | |||
| described in the Simplified BSD License. | described in the Simplified BSD License. | |||
| Table of Contents | Table of Contents | |||
| 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 | |||
| 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 | 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4 | |||
| 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 | 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 | |||
| 2.1. Correlation with RFC 5644 . . . . . . . . . . . . . . . . 5 | 2.1. Correlation with RFC 5644 . . . . . . . . . . . . . . . . 5 | |||
| 3. Flow Classification . . . . . . . . . . . . . . . . . . . . . 6 | 3. Flow Classification . . . . . . . . . . . . . . . . . . . . . 6 | |||
| 4. Multipoint Performance Measurement . . . . . . . . . . . . . 8 | 4. Multipoint Performance Measurement . . . . . . . . . . . . . 9 | |||
| 4.1. Monitoring Network . . . . . . . . . . . . . . . . . . . 9 | 4.1. Monitoring Network . . . . . . . . . . . . . . . . . . . 9 | |||
| 5. Multipoint Packet Loss . . . . . . . . . . . . . . . . . . . 10 | 5. Multipoint Packet Loss . . . . . . . . . . . . . . . . . . . 10 | |||
| 6. Network Clustering . . . . . . . . . . . . . . . . . . . . . 11 | 6. Network Clustering . . . . . . . . . . . . . . . . . . . . . 11 | |||
| 6.1. Algorithm for Clusters Partition . . . . . . . . . . . . 12 | 6.1. Algorithm for Clusters Partition . . . . . . . . . . . . 12 | |||
| 7. Timing Aspects . . . . . . . . . . . . . . . . . . . . . . . 15 | 7. Timing Aspects . . . . . . . . . . . . . . . . . . . . . . . 16 | |||
| 8. Multipoint Delay and Delay Variation . . . . . . . . . . . . 17 | 8. Multipoint Delay and Delay Variation . . . . . . . . . . . . 18 | |||
| 8.1. Delay Measurements on a Multipoint-Paths Basis . . . . . 18 | 8.1. Delay Measurements on a Multipoint-Paths Basis . . . . . 18 | |||
| 8.1.1. Single-Marking Measurement . . . . . . . . . . . . . 18 | 8.1.1. Single-Marking Measurement . . . . . . . . . . . . . 18 | |||
| 8.2. Delay Measurements on a Single-Packet Basis . . . . . . . 18 | 8.2. Delay Measurements on a Single-Packet Basis . . . . . . . 18 | |||
| 8.2.1. Single- and Double-Marking Measurement . . . . . . . 18 | 8.2.1. Single- and Double-Marking Measurement . . . . . . . 18 | |||
| 8.2.2. Hashing Selection Method . . . . . . . . . . . . . . 19 | 8.2.2. Hashing Selection Method . . . . . . . . . . . . . . 19 | |||
| 9. A Closed-Loop Performance-Management Approach . . . . . . . . 21 | 9. A Closed-Loop Performance-Management Approach . . . . . . . . 20 | |||
| 10. Security Considerations . . . . . . . . . . . . . . . . . . . 22 | 10. Security Considerations . . . . . . . . . . . . . . . . . . . 21 | |||
| 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 | 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 22 | |||
| 12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 | 12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 | |||
| 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23 | 13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 | |||
| 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 23 | 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 | |||
| 14.1. Normative References . . . . . . . . . . . . . . . . . . 23 | 14.1. Normative References . . . . . . . . . . . . . . . . . . 22 | |||
| 14.2. Informative References . . . . . . . . . . . . . . . . . 23 | 14.2. Informative References . . . . . . . . . . . . . . . . . 23 | |||
| Appendix A. Changes Log . . . . . . . . . . . . . . . . . . . . 25 | Appendix A. Changes Log . . . . . . . . . . . . . . . . . . . . 24 | |||
| Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 | Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 | |||
| 1. Introduction | 1. Introduction | |||
| The Alternate-Marking method, as described in | The Alternate-Marking method, as described in | |||
| [I-D.fioccola-rfc8321bis], is applicable to a point-to-point path. | [I-D.fioccola-rfc8321bis], is applicable to a point-to-point path. | |||
| The extension proposed in this document applies to the most general | The extension proposed in this document applies to the most general | |||
| case of multipoint-to-multipoint path and enables flexible and | case of multipoint-to-multipoint path and enables flexible and | |||
| adaptive performance measurements in a managed network. | adaptive performance measurements in a managed network. | |||
| The Alternate-Marking methodology described in | The Alternate-Marking methodology described in | |||
| skipping to change at page 3, line 35 ¶ | skipping to change at page 3, line 39 ¶ | |||
| parameters. | parameters. | |||
| The approach presented in this document is applied only to unicast | The approach presented in this document is applied only to unicast | |||
| flows and not to multicast. Broadcast, Unknown Unicast, and | flows and not to multicast. Broadcast, Unknown Unicast, and | |||
| Multicast (BUM) traffic is not considered here, because traffic | Multicast (BUM) traffic is not considered here, because traffic | |||
| replication is not covered by the Multipoint Alternate-Marking | replication is not covered by the Multipoint Alternate-Marking | |||
| method. Furthermore, it can be applicable to anycast flows, and | method. Furthermore, it can be applicable to anycast flows, and | |||
| Equal-Cost Multipath (ECMP) paths can also be easily monitored with | Equal-Cost Multipath (ECMP) paths can also be easily monitored with | |||
| this technique. | this technique. | |||
| In short, [I-D.fioccola-rfc8321bis] applies to point-to-point unicast | [I-D.fioccola-rfc8321bis] applies to point-to-point unicast flows and | |||
| flows and BUM traffic, while this document and its Clustered | BUM traffic. For BUM traffic, the basic method of | |||
| [I-D.fioccola-rfc8321bis] can easily be applied link by link and | ||||
| therefore split the multicast flow tree distribution into separate | ||||
| unicast point-to-point links. While this document and its Clustered | ||||
| Alternate-Marking method is valid for multipoint-to-multipoint | Alternate-Marking method is valid for multipoint-to-multipoint | |||
| unicast flows, anycast, and ECMP flows. | unicast flows, anycast, and ECMP flows. | |||
| Therefore,the Alternate-Marking method can be extended to any kind of | Therefore, the Alternate-Marking method can be extended to any kind | |||
| multipoint-to-multipoint paths, and the network-clustering approach | of multipoint-to-multipoint paths, and the network-clustering | |||
| presented in this document is the formalization of how to implement | approach presented in this document is the formalization of how to | |||
| this property and allow a flexible and optimized performance | implement this property and allow a flexible and optimized | |||
| measurement support for network management in every situation. | performance measurement support for network management in every | |||
| situation. | ||||
| Without network clustering, it is possible to apply Alternate Marking | Without network clustering, it is possible to apply Alternate Marking | |||
| only for all the network or per single flow. Instead, with network | only for all the network or per single flow. Instead, with network | |||
| clustering, it is possible to use the partition of the network into | clustering, it is possible to use the partition of the network into | |||
| clusters at different levels in order to perform the needed degree of | clusters at different levels in order to perform the needed degree of | |||
| detail. In some circumstances, it is possible to monitor a | detail. In some circumstances, it is possible to monitor a | |||
| multipoint network by analyzing the network clustering, without | multipoint network by analyzing the network clustering, without | |||
| examining in depth. In case of problems (packet loss is measured or | examining in depth. In case of problems (packet loss is measured or | |||
| the delay is too high), the filtering criteria could be specified | the delay is too high), the filtering criteria could be specified | |||
| more in order to perform a detailed analysis by using a different | more in order to perform a detailed analysis by using a different | |||
| skipping to change at page 4, line 26 ¶ | skipping to change at page 4, line 33 ¶ | |||
| accurately the network performance monitoring is set up by applying | accurately the network performance monitoring is set up by applying | |||
| the Multipoint Alternate Marking as described in this document. | the Multipoint Alternate Marking as described in this document. | |||
| It is important to underline that, as an extension of | It is important to underline that, as an extension of | |||
| [I-D.fioccola-rfc8321bis], this is a methodology document, so the | [I-D.fioccola-rfc8321bis], this is a methodology document, so the | |||
| mechanism that can be used to transmit the counters and the | mechanism that can be used to transmit the counters and the | |||
| timestamps is out of scope here, and the implementation is open. | timestamps is out of scope here, and the implementation is open. | |||
| Several options are possible -- e.g., see "Enhanced Alternate Marking | Several options are possible -- e.g., see "Enhanced Alternate Marking | |||
| Method" [I-D.zhou-ippm-enhanced-alternate-marking]. | Method" [I-D.zhou-ippm-enhanced-alternate-marking]. | |||
| This document assumes that the blocks are created according to a | ||||
| fixed timer as per [I-D.fioccola-rfc8321bis]. The switching after a | ||||
| fixed number of packets is an additional possibility but it is out of | ||||
| scope here. | ||||
| Note that the fragmented packets case can be managed with the | Note that the fragmented packets case can be managed with the | |||
| Alternate-Marking methodology only if fragmentation happens outside | Alternate-Marking methodology. The same considerations of | |||
| the portion of the network that is monitored. This is always true | [I-D.fioccola-rfc8321bis] apply also in the case of Multipoint | |||
| for both [I-D.fioccola-rfc8321bis] and Multipoint Alternate Marking, | Alternate Marking. As defined in [I-D.fioccola-rfc8321bis] the | |||
| as explained here. | marking node MUST mark all the fragments except in the case of | |||
| fragmentation within the network domain, in that event it is | ||||
| suggested to mark only the first fragment. | ||||
| 1.1. Requirements Language | 1.1. Requirements Language | |||
| The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", | |||
| "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and | "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and | |||
| "OPTIONAL" in this document are to be interpreted as described in BCP | "OPTIONAL" in this document are to be interpreted as described in BCP | |||
| 14 [RFC2119] [RFC8174] when, and only when, they appear in all | 14 [RFC2119] [RFC8174] when, and only when, they appear in all | |||
| capitals, as shown here. | capitals, as shown here. | |||
| 2. Terminology | 2. Terminology | |||
| skipping to change at page 10, line 30 ¶ | skipping to change at page 10, line 30 ¶ | |||
| \ <> R9 <>--- | \ <> R9 <>--- | |||
| \ +------+ | \ +------+ | |||
| \ | \ | |||
| \ +------+ | \ +------+ | |||
| <> R10 <>--- | <> R10 <>--- | |||
| +------+ | +------+ | |||
| Figure 2: Monitoring Network Graph | Figure 2: Monitoring Network Graph | |||
| Each monitoring point is characterized by the packet counter that | Each monitoring point is characterized by the packet counter that | |||
| refers only to a marking period of the monitored flow. | refers only to a marking period of the monitored flow. Also, it is | |||
| assumed that there be a monitoring point at all possible egress | ||||
| points of the multipoint monitored network. | ||||
| The same is also applicable for the delay, but it will be described | The same is also applicable for the delay, but it will be described | |||
| in the following sections. | in the following sections. | |||
| 5. Multipoint Packet Loss | 5. Multipoint Packet Loss | |||
| Since all the packets of the considered flow leaving the network have | Since all the packets of the considered flow leaving the network have | |||
| previously entered the network, the number of packets counted by all | previously entered the network, the number of packets counted by all | |||
| the input nodes is always greater than, or equal to, the number of | the input nodes is always greater than, or equal to, the number of | |||
| packets counted by all the output nodes. Noninitial fragments are | packets counted by all the output nodes. Noninitial fragments are | |||
| skipping to change at page 16, line 39 ¶ | skipping to change at page 16, line 47 ¶ | |||
| When we expand to multipoint-to-multipoint flows, we have to consider | When we expand to multipoint-to-multipoint flows, we have to consider | |||
| that all source nodes mark the traffic, and this adds more | that all source nodes mark the traffic, and this adds more | |||
| complexity. | complexity. | |||
| Regarding the timing aspects of the methodology, | Regarding the timing aspects of the methodology, | |||
| [I-D.fioccola-rfc8321bis] already describes two contributions that | [I-D.fioccola-rfc8321bis] already describes two contributions that | |||
| are taken into account: the clock error between network devices and | are taken into account: the clock error between network devices and | |||
| the network delay between measurement points. | the network delay between measurement points. | |||
| But we should now consider an additional contribution. Since all | Since there are more marking nodes in a multipoint environment, all | |||
| source nodes mark the traffic, the source measurement intervals can | source nodes mark the traffic based on synchronized clock time but | |||
| be of different lengths and with different offsets, and this mismatch | the marking periods can be of different lengths and with different | |||
| m can be added to d, as shown in Figure 5. | offsets. This is because there can be an additional contribution to | |||
| consider since different nodes are marking the traffic and the | ||||
| batches get mixed in a multipoint flow. For example, a marking node | ||||
| may apply the marking with a delay because it is overloaded while the | ||||
| other marking nodes are not. To take into account this possible | ||||
| additional gap between the sources it is introduced a mismatch m that | ||||
| can be added to d, as shown in Figure 5. | ||||
| ...BBBBBBBBB | AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA | BBBBBBBBB... | ...BBBBBBBBB | AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA | BBBBBBBBB... | |||
| |<======================================>| | |<======================================>| | |||
| | L | | | L | | |||
| ...=========>|<==================><==================>|<==========... | ...=========>|<==================><==================>|<==========... | |||
| | L/2 L/2 | | | L/2 L/2 | | |||
| |<=><===>| |<===><=>| | |<=><===>| |<===><=>| | |||
| m d | | d m | m d | | d m | |||
| |<====================>| | |<====================>| | |||
| available counting interval | available counting interval | |||
| skipping to change at page 17, line 38 ¶ | skipping to change at page 17, line 44 ¶ | |||
| L - 2m - 2d > 0. | L - 2m - 2d > 0. | |||
| This formula needs to be verified for each measurement point on the | This formula needs to be verified for each measurement point on the | |||
| multipoint path, where m is misalignment between the marking source | multipoint path, where m is misalignment between the marking source | |||
| routers, while d, already introduced in [I-D.fioccola-rfc8321bis], | routers, while d, already introduced in [I-D.fioccola-rfc8321bis], | |||
| takes into account clock error and network delay between network | takes into account clock error and network delay between network | |||
| nodes. Therefore, the mismatch between measurement intervals must | nodes. Therefore, the mismatch between measurement intervals must | |||
| satisfy this condition. | satisfy this condition. | |||
| Also, it is worth highlighting that the formula above is exactly the | ||||
| same of [I-D.fioccola-rfc8321bis] if m=0, indeed in case of a point- | ||||
| to-point flow there is only one marking node and m=0. | ||||
| Note that the timing considerations are valid for both packet loss | Note that the timing considerations are valid for both packet loss | |||
| and delay measurements. | and delay measurements. | |||
| 8. Multipoint Delay and Delay Variation | 8. Multipoint Delay and Delay Variation | |||
| The same line of reasoning can be applied to delay and delay | The same line of reasoning can be applied to delay and delay | |||
| variation. Similarly to the delay measurements defined in | variation. Similarly to the delay measurements defined in | |||
| [I-D.fioccola-rfc8321bis], the marking batches anchor the samples to | [I-D.fioccola-rfc8321bis], the marking batches anchor the samples to | |||
| a particular period, and this is the time reference that can be used. | a particular period, and this is the time reference that can be used. | |||
| It is important to highlight that both delay and delay-variation | It is important to highlight that both delay and delay-variation | |||
| skipping to change at page 19, line 28 ¶ | skipping to change at page 19, line 41 ¶ | |||
| 8.2.2. Hashing Selection Method | 8.2.2. Hashing Selection Method | |||
| RFCs 5474 [RFC5474] and 5475 [RFC5475] introduce sampling and | RFCs 5474 [RFC5474] and 5475 [RFC5475] introduce sampling and | |||
| filtering techniques for IP packet selection. | filtering techniques for IP packet selection. | |||
| The hash-based selection methodologies for delay measurement can work | The hash-based selection methodologies for delay measurement can work | |||
| in a multipoint-to-multipoint path and MAY be used either coupled to | in a multipoint-to-multipoint path and MAY be used either coupled to | |||
| mean delay or stand-alone. | mean delay or stand-alone. | |||
| [I-D.mizrahi-ippm-compact-alternate-marking] introduces how to use | [I-D.mizrahi-ippm-marking] introduces how to use the hash method (RFC | |||
| the hash method (RFC 5474 [RFC5474] and RFC 5475 [RFC5475]) combined | 5474 [RFC5474] and RFC 5475 [RFC5475]) combined with the Alternate- | |||
| with the Alternate-Marking method for point-to-point flows. It is | Marking method for point-to-point flows. It is also called Mixed | |||
| also called Mixed Hashed Marking: the coupling of a marking method | Hashed Marking: the coupling of a marking method and hashing | |||
| and hashing technique is very useful, because the marking batches | technique is very useful, because the marking batches anchor the | |||
| anchor the samples selected with hashing, and this simplifies the | samples selected with hashing, and this simplifies the correlation of | |||
| correlation of the hashing packets along the path. | the hashing packets along the path. | |||
| It is possible to use a basic-hash or a dynamic-hash method. One of | It is possible to use a basic-hash or a dynamic-hash method. One of | |||
| the challenges of the basic approach is that the frequency of the | the challenges of the basic approach is that the frequency of the | |||
| sampled packets may vary considerably. For this reason, the dynamic | sampled packets may vary considerably. For this reason, the dynamic | |||
| approach has been introduced for point-to-point flows in order to | approach has been introduced for point-to-point flows in order to | |||
| have the desired and almost fixed number of samples for each | have the desired and almost fixed number of samples for each | |||
| measurement period. Using the hash-based sampling, the number of | measurement period. Using the hash-based sampling, the number of | |||
| samples may vary a lot because it depends on the packet rate that is | samples may vary a lot because it depends on the packet rate that is | |||
| variable. The dynamic approach helps to have an almost fixed number | variable. The dynamic approach helps to have an almost fixed number | |||
| of samples for each marking period, and this is a better option for | of samples for each marking period, and this is a better option for | |||
| making regular measurements over time. In the hash-based sampling, | making regular measurements over time. In the hash-based sampling, | |||
| Alternate Marking is used to create periods, so that hash-based | Alternate Marking is used to create periods, so that hash-based | |||
| samples are divided into batches, which allows anchoring the selected | samples are divided into batches, which allows anchoring the selected | |||
| samples to their period. Moreover, in the dynamic hash-based | samples to their period. Moreover, in the dynamic hash-based | |||
| sampling, by dynamically adapting the length of the hash value, the | sampling, by dynamically adapting the length of the hash value, the | |||
| number of samples is bounded in each marking period. This can be | number of samples is bounded in each marking period. | |||
| realized by choosing the maximum number of samples (NMAX) to be | ||||
| caught in a marking period. The algorithm starts with only a few | ||||
| hash bits, which permits selecting a greater percentage of packets | ||||
| (e.g., with 0 bits of hash all the packets are sampled, with 1 bit of | ||||
| hash half of the packets are sampled, and so on). When the number of | ||||
| selected packets reaches NMAX, a hashing bit is added. As a | ||||
| consequence, the sampling proceeds at half of the original rate, and | ||||
| also the packets already selected that do not match the new hash are | ||||
| discarded. This step can be repeated iteratively. It is assumed | ||||
| that each sample includes the timestamp (used for delay measurement) | ||||
| and the hash value, allowing the management system to match the | ||||
| samples received from the two measurement points. The dynamic | ||||
| process statistically converges at the end of a marking period, and | ||||
| the final number of selected samples is between NMAX/2 and NMAX. | ||||
| Therefore, the dynamic approach paces the sampling rate, allowing to | ||||
| bound the number of sampled packets per sampling period. | ||||
| In a multipoint environment, the behavior is similar to a point-to- | ||||
| point flow. In particular, in the context of a multipoint-to- | ||||
| multipoint flow, the dynamic hash could be the solution for | ||||
| performing delay measurements on specific packets and overcoming the | ||||
| single- and double-marking limitations. | ||||
| The management system receives the samples, including the timestamps | ||||
| and the hash value, from all the MPs, and this happens for both | ||||
| point-to-point and multipoint-to-multipoint flows. Then, the longest | ||||
| hash used by the MPs is deduced and applied to couple timestamps from | ||||
| either the same packets of 2 MPs of a point-to-point path, or the | ||||
| input and output MPs of a cluster (or a super cluster or the entire | ||||
| network). But some considerations are needed: if there isn't packet | ||||
| loss, the set of input samples is always equal to the set of output | ||||
| samples. In the case of packet loss, the set of output samples can | ||||
| be a subset of input samples, but the method still works because, at | ||||
| the end, it is easy to couple the input and output timestamps of each | ||||
| caught packet using the hash (in particular, the "unused part of the | ||||
| hash" that should be different for each packet). | ||||
| Therefore, the basic hash is logically similar to the double-marking | In a multipoint environment, the hashing selection MAY be the | |||
| method, and in the case of a point-to-point path, double-marking and | solution for performing delay measurements on specific packets and | |||
| basic-hash selection are equivalent. The dynamic approach scales the | overcoming the single- and double-marking limitations. | |||
| number of measurements per interval. It would seem that double | ||||
| marking would also work well if we reduced the interval length, but | ||||
| this can be done only for a point-to-point path and not for a | ||||
| multipoint path, where we cannot couple the picked packets in a | ||||
| multipoint path. So, in general, if we want to get delay | ||||
| measurements on the basis of a multipoint-to-multipoint path, and | ||||
| want to select more than one packet per period, double marking cannot | ||||
| be used because we could not be able to couple the picked packets | ||||
| between input and output nodes. On the other hand, we can do that by | ||||
| using hashing selection. | ||||
| 9. A Closed-Loop Performance-Management Approach | 9. A Closed-Loop Performance-Management Approach | |||
| The Multipoint Alternate-Marking framework that is introduced in this | The Multipoint Alternate-Marking framework that is introduced in this | |||
| document adds flexibility to Performance Management (PM), because it | document adds flexibility to Performance Management (PM), because it | |||
| can reduce the order of magnitude of the packet counters. This | can reduce the order of magnitude of the packet counters. This | |||
| allows an SDN orchestrator to supervise, control, and manage PM in | allows an SDN orchestrator to supervise, control, and manage PM in | |||
| large networks. | large networks. | |||
| The monitoring network can be considered as a whole or split into | The monitoring network can be considered as a whole or split into | |||
| skipping to change at page 22, line 42 ¶ | skipping to change at page 22, line 11 ¶ | |||
| Internet. However, implementation of this method must be mindful of | Internet. However, implementation of this method must be mindful of | |||
| security and privacy concerns, as explained in | security and privacy concerns, as explained in | |||
| [I-D.fioccola-rfc8321bis]. | [I-D.fioccola-rfc8321bis]. | |||
| 11. IANA Considerations | 11. IANA Considerations | |||
| This document has no IANA actions. | This document has no IANA actions. | |||
| 12. Contributors | 12. Contributors | |||
| Tianran Zhou | ||||
| Huawei Technologies | ||||
| Email: zhoutianran@huawei.com | ||||
| Greg Mirsky | Greg Mirsky | |||
| Ericsson | Ericsson | |||
| Email: gregimirsky@gmail.com | Email: gregimirsky@gmail.com | |||
| Tal Mizrahi | Tal Mizrahi | |||
| Huawei Technologies | Huawei Technologies | |||
| Email: tal.mizrahi.phd@gmail.com | Email: tal.mizrahi.phd@gmail.com | |||
| Xiao Min | Xiao Min | |||
| ZTE Corp. | ZTE Corp. | |||
| skipping to change at page 23, line 19 ¶ | skipping to change at page 22, line 32 ¶ | |||
| 13. Acknowledgements | 13. Acknowledgements | |||
| The authors would like to thank Martin Duke and Tommy Pauly for their | The authors would like to thank Martin Duke and Tommy Pauly for their | |||
| assistance and their detailed and precious reviews. | assistance and their detailed and precious reviews. | |||
| 14. References | 14. References | |||
| 14.1. Normative References | 14.1. Normative References | |||
| [I-D.fioccola-rfc8321bis] | ||||
| Fioccola, G., Cociglio, M., Mirsky, G., and T. Mizrahi, | ||||
| "Alternate-Marking Method", draft-fioccola-rfc8321bis-00 | ||||
| (work in progress), November 2021. | ||||
| [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate | |||
| Requirement Levels", BCP 14, RFC 2119, | Requirement Levels", BCP 14, RFC 2119, | |||
| DOI 10.17487/RFC2119, March 1997, | DOI 10.17487/RFC2119, March 1997, | |||
| <https://www.rfc-editor.org/info/rfc2119>. | <https://www.rfc-editor.org/info/rfc2119>. | |||
| [RFC5474] Duffield, N., Ed., Chiou, D., Claise, B., Greenberg, A., | [RFC5474] Duffield, N., Ed., Chiou, D., Claise, B., Greenberg, A., | |||
| Grossglauser, M., and J. Rexford, "A Framework for Packet | Grossglauser, M., and J. Rexford, "A Framework for Packet | |||
| Selection and Reporting", RFC 5474, DOI 10.17487/RFC5474, | Selection and Reporting", RFC 5474, DOI 10.17487/RFC5474, | |||
| March 2009, <https://www.rfc-editor.org/info/rfc5474>. | March 2009, <https://www.rfc-editor.org/info/rfc5474>. | |||
| skipping to change at page 23, line 45 ¶ | skipping to change at page 23, line 16 ¶ | |||
| Metrics (IPPM): Spatial and Multicast", RFC 5644, | Metrics (IPPM): Spatial and Multicast", RFC 5644, | |||
| DOI 10.17487/RFC5644, October 2009, | DOI 10.17487/RFC5644, October 2009, | |||
| <https://www.rfc-editor.org/info/rfc5644>. | <https://www.rfc-editor.org/info/rfc5644>. | |||
| [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC | [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC | |||
| 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, | 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, | |||
| May 2017, <https://www.rfc-editor.org/info/rfc8174>. | May 2017, <https://www.rfc-editor.org/info/rfc8174>. | |||
| 14.2. Informative References | 14.2. Informative References | |||
| [I-D.fioccola-rfc8321bis] | ||||
| Fioccola, G., Cociglio, M., Mirsky, G., and T. Mizrahi, | ||||
| "Alternate-Marking Method", draft-fioccola-rfc8321bis-00 | ||||
| (work in progress), November 2021. | ||||
| [I-D.ietf-ippm-route] | [I-D.ietf-ippm-route] | |||
| Alvarez-Hamelin, J. I., Morton, A., Fabini, J., Pignataro, | Alvarez-Hamelin, J. I., Morton, A., Fabini, J., Pignataro, | |||
| C., and R. Geib, "Advanced Unidirectional Route Assessment | C., and R. Geib, "Advanced Unidirectional Route Assessment | |||
| (AURA)", draft-ietf-ippm-route-10 (work in progress), | (AURA)", draft-ietf-ippm-route-10 (work in progress), | |||
| August 2020. | August 2020. | |||
| [I-D.mizrahi-ippm-compact-alternate-marking] | [I-D.mizrahi-ippm-marking] | |||
| Mizrahi, T., Arad, C., Fioccola, G., Cociglio, M., Chen, | Mizrahi, T., Fioccola, G., Cociglio, M., Chen, M., and G. | |||
| M., Zheng, L., and G. Mirsky, "Compact Alternate Marking | Mirsky, "Marking Methods for Performance Measurement", | |||
| Methods for Passive and Hybrid Performance Monitoring", | draft-mizrahi-ippm-marking-00 (work in progress), October | |||
| draft-mizrahi-ippm-compact-alternate-marking-05 (work in | 2021. | |||
| progress), July 2019. | ||||
| [I-D.song-opsawg-ifit-framework] | [I-D.song-opsawg-ifit-framework] | |||
| Song, H., Qin, F., Chen, H., Jin, J., and J. Shin, "In- | Song, H., Qin, F., Chen, H., Jin, J., and J. Shin, "In- | |||
| situ Flow Information Telemetry", draft-song-opsawg-ifit- | situ Flow Information Telemetry", draft-song-opsawg-ifit- | |||
| framework-16 (work in progress), October 2021. | framework-16 (work in progress), October 2021. | |||
| [I-D.zhou-ippm-enhanced-alternate-marking] | [I-D.zhou-ippm-enhanced-alternate-marking] | |||
| Zhou, T., Fioccola, G., Liu, Y., Lee, S., Cociglio, M., | Zhou, T., Fioccola, G., Liu, Y., Lee, S., Cociglio, M., | |||
| and W. Li, "Enhanced Alternate Marking Method", draft- | and W. Li, "Enhanced Alternate Marking Method", draft- | |||
| zhou-ippm-enhanced-alternate-marking-07 (work in | zhou-ippm-enhanced-alternate-marking-07 (work in | |||
| skipping to change at page 25, line 13 ¶ | skipping to change at page 24, line 19 ¶ | |||
| <https://www.rfc-editor.org/info/rfc8889>. | <https://www.rfc-editor.org/info/rfc8889>. | |||
| Appendix A. Changes Log | Appendix A. Changes Log | |||
| Changes from RFC 8889 include: | Changes from RFC 8889 include: | |||
| o Minor editorial changes | o Minor editorial changes | |||
| o Removed section on "Examples of application" | o Removed section on "Examples of application" | |||
| Changes in v-(01) include: | ||||
| o Considerations on BUM traffic | ||||
| o Reference to RFC8321bis for the fragmentation part | ||||
| o Revised section on "Delay Measurements on a Single-Packet Basis" | ||||
| o Revised section on "Timing Aspects" | ||||
| Authors' Addresses | Authors' Addresses | |||
| Giuseppe Fioccola (editor) | Giuseppe Fioccola (editor) | |||
| Huawei Technologies | Huawei Technologies | |||
| Riesstrasse, 25 | Riesstrasse, 25 | |||
| Munich 80992 | Munich 80992 | |||
| Germany | Germany | |||
| Email: giuseppe.fioccola@huawei.com | Email: giuseppe.fioccola@huawei.com | |||
| skipping to change at page 25, line 30 ¶ | skipping to change at page 25, line 4 ¶ | |||
| Email: giuseppe.fioccola@huawei.com | Email: giuseppe.fioccola@huawei.com | |||
| Mauro Cociglio | Mauro Cociglio | |||
| Telecom Italia | Telecom Italia | |||
| Via Reiss Romoli, 274 | Via Reiss Romoli, 274 | |||
| Torino 10148 | Torino 10148 | |||
| Italy | Italy | |||
| Email: mauro.cociglio@telecomitalia.it | Email: mauro.cociglio@telecomitalia.it | |||
| Amedeo Sapio | Amedeo Sapio | |||
| Intel Corporation | Intel Corporation | |||
| 4750 Patrick Henry Dr. | 4750 Patrick Henry Dr. | |||
| Santa Clara, CA 95054 | Santa Clara, CA 95054 | |||
| USA | USA | |||
| Email: amedeo.sapio@intel.com | Email: amedeo.sapio@intel.com | |||
| Riccardo Sisto | Riccardo Sisto | |||
| Politecnico di Torino | Politecnico di Torino | |||
| Corso Duca degli Abruzzi, 24 | Corso Duca degli Abruzzi, 24 | |||
| Torino 10129 | Torino 10129 | |||
| Italy | Italy | |||
| Email: riccardo.sisto@polito.it | Email: riccardo.sisto@polito.it | |||
| Tianran Zhou | ||||
| Huawei Technologies | ||||
| 156 Beiqing Rd. | ||||
| Beijing 100095 | ||||
| China | ||||
| Email: zhoutianran@huawei.com | ||||
| End of changes. 27 change blocks. | ||||
| 104 lines changed or deleted | 87 lines changed or added | |||
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