Multipoint Alternate Marking method for passive and hybrid performance monitoring
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This is an older version of an Internet-Draft that was ultimately published as RFC 8889.
|Authors||Giuseppe Fioccola , Mauro Cociglio , Amedeo Sapio , Riccardo Sisto|
|RFC stream||Internet Engineering Task Force (IETF)|
GENART Last Call review (of -06) Ready with Nits
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IPPM Working Group G. Fioccola, Ed. Internet-Draft Huawei Technologies Intended status: Experimental M. Cociglio Expires: May 9, 2019 Telecom Italia A. Sapio R. Sisto Politecnico di Torino November 5, 2018 Multipoint Alternate Marking method for passive and hybrid performance monitoring draft-ietf-ippm-multipoint-alt-mark-00 Abstract The Alternate Marking method, as presented in RFC 8321 [RFC8321], can be applied only to point-to-point flows because it assumes that all the packets of the flow measured on one node are measured again by a single second node. This document aims to generalize and expand this methodology to measure any kind of unicast flows, whose packets can follow several different paths in the network, in wider terms a multipoint-to-multipoint network. For this reason the technique here described is called Multipoint Alternate Marking. Some definitions here introduced extend the scope of RFC 5644 [RFC5644] in the context of alternate marking schema. Requirements Language 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]. 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." Fioccola, et al. Expires May 9, 2019 [Page 1] Internet-Draft Multipoint AM November 2018 This Internet-Draft will expire on May 9, 2019. Copyright Notice Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved. 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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Correlation with RFC5644 . . . . . . . . . . . . . . . . . . 4 3. Flow classification . . . . . . . . . . . . . . . . . . . . . 4 4. Multipoint Performance Measurement . . . . . . . . . . . . . 7 4.1. Monitoring Network . . . . . . . . . . . . . . . . . . . 7 5. Multipoint Packet Loss . . . . . . . . . . . . . . . . . . . 8 6. Network Clustering . . . . . . . . . . . . . . . . . . . . . 9 6.1. Algorithm for Cluster partition . . . . . . . . . . . . . 10 7. Timing Aspects . . . . . . . . . . . . . . . . . . . . . . . 12 8. Multipoint Delay and Delay Variation . . . . . . . . . . . . 14 8.1. Delay measurements on multipoint paths basis . . . . . . 14 8.1.1. Single Marking measurement . . . . . . . . . . . . . 14 8.2. Delay measurements on single packets basis . . . . . . . 14 8.2.1. Single and Double Marking measurement . . . . . . . . 14 8.2.2. Hashing selection method . . . . . . . . . . . . . . 15 9. An SDN enabled Performance Management . . . . . . . . . . . . 17 10. Examples of application . . . . . . . . . . . . . . . . . . . 17 11. Security Considerations . . . . . . . . . . . . . . . . . . . 18 12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 18 14. References . . . . . . . . . . . . . . . . . . . . . . . . . 18 14.1. Normative References . . . . . . . . . . . . . . . . . . 18 14.2. Informative References . . . . . . . . . . . . . . . . . 18 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19 Fioccola, et al. Expires May 9, 2019 [Page 2] Internet-Draft Multipoint AM November 2018 1. Introduction The alternate marking method, as presented until now, is applicable to a point-to-point path; so the extension proposed in this document explains the most general case of multipoint-to-multipoint path and enables flexible and adaptive performance measurements in a managed network. The Alternate Marking methodology described in RFC 8321 [RFC8321] has the property to synchronize measurements in different points maintaining the coherence of the counters. So it is possible to show what is happening in every marking period for each monitored flow. The monitoring parameters are the packet counter and timestamps of a flow for each marking period. There are some applications of the alternate marking method where there are a lot of monitored flows and nodes. Multipoint Alternate Marking aims to reduce these values and makes the performance monitoring more flexible in case a detailed analysis is not needed. For instance, by considering n measurement points and m monitored flows,the order of magnitude of the packet counters for each time interval is n*m*2 (1 per color). If both n and m are high values the packet counters increase a lot and Multipoint Alternate Marking offers a tool to control these parameters. The approach presented in this document is applied only to unicast flows and not to multicast. BUM (Boradcast Unkown Unicast Multicast) traffic is not considered here, because traffic replication is not covered by the Multipoint Alternate Marking method. Alternate Marking method works by definition for multipoint to multipoint paths but the network clustering approach presented in this document is the formalization of how to implement this property and it allows a flexible and optimized performance measurement support. Without network clustering, it is possible to apply alternate marking only for all the network or per single flow. Instead, with network clustering, it is possible to use the network clusters partition at different levels to perform the needed degree of detail. In some circumstances it is possible to monitor a Multipoint Network by analyzing the Network Clustering, without examining in depth. In case of problems (packet loss is measured or the delay is too high) the filtering criteria could be specified more in order to perform a detailed analysis by using a different combination of clusters up to a per-flow measurement as described in RFC 8321 [RFC8321]. Fioccola, et al. Expires May 9, 2019 [Page 3] Internet-Draft Multipoint AM November 2018 An application could be the Software Defined Network (SDN) paradigm where the SDN Controllers are the brains of the network and can manage flow control to the switches and routers and, in the same way, can calibrate the performance measurements depending on the necessity. An SDN Controller Application can orchestrate how deep the network performance monitoring is setup. 2. Correlation with RFC5644 RFC 5644 [RFC5644] is limited to active measurements using a single source packet or stream, and observations of corresponding packets along the path (spatial), at one or more destinations (one-to-group), or both. Instead, the scope of this memo is to define multiparty metrics for passive and hybrid measurements in a group-to-group topology with multiple sources and destinations. RFC 5644 [RFC5644] introduces metric names that can be reused also here but have to be extended and rephrased to be applied to the alternate marking schema: a. the multiparty metrics are not only one-to-group metrics but can be also group-to-group metrics; b. the spatial metrics, used for measuring the performance of segments of a source to destination path, are applied here to group-to-group segments (called Clusters). 3. Flow classification An unicast flow is identified by all the packets having a set of common characteristics. This definition is inspired by RFC 7011 [RFC7011]. As an example, by considering a flow as all the packets sharing the same source IP address or the same destination IP address, it is easy to understand that the resulting pattern will not be a point-to-point connection, but a point-to-multipoint or multipoint-to-point connection. In general a flow can be defined by a set of selection rules used to match a subset of the packets processed by the network device. These rules specify a set of headers fields (Identification Fields) and the relative values that must be found in matching packets. The choice of the identification fields directly affects the type of paths that the flow would follow in the network. In fact, it is possible to relate a set of identification fields with the pattern of the resulting graphs, as listed in Figure 1. Fioccola, et al. Expires May 9, 2019 [Page 4] Internet-Draft Multipoint AM November 2018 A TCP 5-tuple usually identifies flows following either a single path or a point-to-point multipath (in case of load balancing). On the contrary, a single source address selects flows following a point-to- multipoint, while a multipoint-to-point can be the result of a matching on a single destination address. In case a selection rule and its reverse are used for bidirectional measurements, they can correspond to a point-to-multipoint in one direction and a multipoint-to-point in the opposite direction. In this way the flows to be monitored are selected into the monitoring points using packet selection rules, that can also change the pattern of the monitored network. The alternate marking method is applicable only to a single path (and partially to a one-to-one multipath), so the extension proposed in this document is suitable also for the most general case of multipoint-to-multipoint, which embraces all the other patterns of Figure 1. point-to-point single path +------+ +------+ +------+ ---<> R1 <>----<> R2 <>----<> R3 <>--- +------+ +------+ +------+ point-to-point multipath +------+ <> R2 <> / +------+ \ / \ +------+ / \ +------+ ---<> R1 <> <> R4 <>--- +------+ \ / +------+ \ / \ +------+ / <> R3 <> +------+ point-to-multipoint +------+ <> R4 <>--- / +------+ +------+ / <> R2 <> / +------+ \ +------+ / \ +------+ ---<> R1 <> <> R5 <>--- +------+ \ +------+ Fioccola, et al. Expires May 9, 2019 [Page 5] Internet-Draft Multipoint AM November 2018 \ +------+ <> R3 <> +------+ \ \ +------+ <> R6 <>--- +------+ multipoint-to-point +------+ ---<> R1 <> +------+ \ \ +------+ <> R4 <> / +------+ \ +------+ / \ +------+ ---<> R2 <> <> R4 <>--- +------+ / +------+ +------+ / <> R5 <> / +------+ +------+ / ---<> R3 <> +------+ multipoint-to-multipoint +------+ +------+ ---<> R1 <> <> R6 <>--- +------+ \ / +------+ \ +------+ / <> R4 <> +------+ \ +------+ \ +------+ ---<> R2 <> <> R7 <>--- +------+ \ / +------+ \ +------+ / <> R5 <> / +------+ \ +------+ / \ +------+ ---<> R3 <> <> R8 <>--- +------+ +------+ Figure 1: Flow classification Fioccola, et al. Expires May 9, 2019 [Page 6] Internet-Draft Multipoint AM November 2018 4. Multipoint Performance Measurement By Using the "traditional" alternate marking method only point-to- point paths can be monitored. To have an IP (TCP/UDP) flow that follows a point-to-point path we have to define, with a specific value, 5 identification fields (IP Source, IP Destination, Transport Protocol, Source Port, Destination Port). Multipoint Alternate Marking enables the performance measurement for multipoint flows selected by identification fields without any constraints (even the entire network production traffic). It is also possible to use multiple marking points for the same monitored flow. 4.1. Monitoring Network The Monitoring Network is deduced from the Production Network, by identifying the nodes of the graph that are the measurement points, and the links that are the connections between measurement points. There are some techniques that can help with the building of the monitoring network (as an example it is possible to mention [I-D.amf-ippm-route]). In general there are different options: the monitoring network can be obtained by considering all the possible paths for the traffic or also by checking the traffic sometimes and update the graph consequently. So a graph model of the monitoring network can be built according to the alternate marking method: the monitored interfaces and links are identified. Only the measurement points and links where the traffic has flowed have to be represented in the graph. The following figure shows a simple example of a Monitoring Network graph: Fioccola, et al. Expires May 9, 2019 [Page 7] Internet-Draft Multipoint AM November 2018 +------+ <> R6 <>--- / +------+ +------+ +------+ / <> R2 <>---<> R4 <> / +------+ \ +------+ \ / \ \ +------+ +------+ / +------+ \ +------+ <> R7 <>--- ---<> R1 <>---<> R3 <>---<> R5 <> +------+ +------+ \ +------+ \ +------+ \ \ \ \ +------+ \ \ <> R8 <>--- \ \ +------+ \ \ \ \ +------+ \ <> R9 <>--- \ +------+ \ \ +------+ <> R10 <>--- +------+ Figure 2: Monitoring Network Graph Each monitoring point is characterized by the packet counter that refers only to a marking period of the monitored flow. The same is applicable also for the delay but it will be described in the following sections. 5. Multipoint Packet Loss Since all the packets of the considered flow leaving the network have previously entered the network, the number of packets counted by all the input nodes is always greater or equal than the number of packets counted by all the output nodes. And in case of no packet loss occurring in the marking period, if all the input and output points of the network domain to be monitored are measurement points, the sum of the number of packets on all the ingress interfaces and on all the egress interfaces is the same. In this circumstance, if no packet loss occurs, the intermediate measurement points have only the task to split the measurement. It is possible to define the Network Packet Loss (for 1 flow, for 1 period): <<In a packet network, the number of lost packets is the Fioccola, et al. Expires May 9, 2019 [Page 8] Internet-Draft Multipoint AM November 2018 number of packets counted by the input nodes minus the number of packets counted by the output nodes>>. This is true for every packet flow in each marking period. The Monitored Network Packet Loss with n input nodes and m output nodes is given by: PL = (PI1 + PI2 +...+ PIn) - (PO1 + PO2 +...+ POm) where: PL is the Network Packet Loss (number of lost packets) PIi is the Number of packets flowed through the i-th Input node in this period POj is the Number of packets flowed through the j-th Output node in this period The equation is applied on a per-time-interval basis. 6. Network Clustering The previous Equation can determine the number of packets lost globally in the monitored network, exploiting only the data provided by the counters in the input and output nodes. In addition it is also possible to leverage the data provided by the other counters in the network to converge on the smallest identifiable subnetworks where the losses occur. These subnetworks are named Clusters. A Cluster graph is a subnetwork of the entire Monitoring Network graph that still satisfies the packet loss equation where PL in this case is the number of packets lost in the Cluster. For this reason a Cluster should contain all the arcs emanating from its input nodes and all the arcs terminating at its output nodes. This ensures that we can count all the packets (and only those) exiting an input node again at the output node, whatever path they follow. In a completely monitored network (a network where every network interface is monitored), each network device corresponds to a Cluster and each physical link corresponds to two Clusters (one for each direction). Fioccola, et al. Expires May 9, 2019 [Page 9] Internet-Draft Multipoint AM November 2018 Clusters can have different sizes depending on flow filtering criteria adopted. Moreover, sometimes Clusters can be optionally simplified. For example when two monitored interfaces are divided by a single router (one is the input interface and the other is the output interface and the router has only these two interfaces), instead of counting exactly twice, upon entering and leaving, it is possible to consider a single measurement point (in this case we do not care of the internal packet loss of the router). 6.1. Algorithm for Cluster partition A simple algorithm can be applied in order to split our monitoring network into Clusters. It is a two-step algorithm: o Group the links where there is the same starting node; o Join the grouped links with at least one ending node in common. In our monitoring network graph example it is possible to identify the Clusters partition by applying this two-step algorithm. The first step identifies the following groups: 1. Group 1: (R1-R2), (R1-R3), (R1-R10) 2. Group 2: (R2-R4), (R2-R5) 3. Group 3: (R3-R5), (R3-R9) 4. Group 4: (R4-R6), (R4-R7) 5. Group 5: (R5-R8) And then, the second step builds the Clusters partition (in particular we can underline that Group 2 and Group 3 connect together, since R5 is in common): 1. Cluster 1: (R1-R2), (R1-R3), (R1-R10) 2. Cluster 2: (R2-R4), (R2-R5), (R3-R5), (R3-R9) 3. Cluster 3: (R4-R6), (R4-R7) 4. Cluster 4: (R5-R8) In the end the following 4 Clusters are obtained: Fioccola, et al. Expires May 9, 2019 [Page 10] Internet-Draft Multipoint AM November 2018 Cluster 1 +------+ <> R2 <>--- / +------+ / +------+ / +------+ ---<> R1 <>---<> R3 <>--- +------+ \ +------+ \ \ \ \ \ \ \ \ \ +------+ <> R10 <>--- +------+ Cluster 2 +------+ +------+ ---<> R2 <>---<> R4 <>--- +------+ \ +------+ \ +------+ \ +------+ ---<> R3 <>---<> R5 <>--- +------+ \ +------+ \ \ \ \ \ +------+ <> R9 <>--- +------+ Cluster 3 +------+ <> R6 <>--- / +------+ +------+ / ---<> R4 <> +------+ \ \ +------+ <> R7 <>--- +------+ Fioccola, et al. Expires May 9, 2019 [Page 11] Internet-Draft Multipoint AM November 2018 Cluster 4 +------+ ---<> R5 <> +------+ \ \ +------+ <> R8 <>--- +------+ Figure 3: Clusters example There are Clusters with more than 2 nodes and two-nodes Clusters. In the two-nodes Clusters the loss is on the link (Cluster 4). In more- than-2-nodes Clusters the loss is on the Cluster but we cannot know in which link (Cluster 1, 2, 3). In this way the calculation of packet loss can be made on Cluster basis. Note that CIR(Committed Information Rate) and EIR(Excess Information Rate) can also be deduced on Cluster basis. Obviously, by combining some Clusters in a new connected subnetwork (called Super Cluster) the Packet Loss Rule is still true. In this way in a very large network there is no need to configure detailed filter criteria to inspect the traffic. You can check multipoint network and only in case of problems you can go deep with a step-by-step cluster analysis, but only for the cluster or combination of clusters where the problem happens. 7. Timing Aspects The mark switching approach based on a fixed timer is considered in this document. So, if we analyze a multipoint-to-multipoint path with more than one marking node, it is important to recognize the reference measurement interval. In general the measurement interval for describing the results is the interval of the marking node that is more aligned with the start of the measurement, as reported in the following figure. Fioccola, et al. Expires May 9, 2019 [Page 12] Internet-Draft Multipoint AM November 2018 time -> start stop T(R1) |-------------| T(R2) |-------------| T(R3) |------------| Figure 4: Measurement Interval T(R1) is the measurement interval and this is essential in order to be compatible and make comparison with other active/passive/hybrid Packet Loss metrics. That is why, when we expand to multipoint-to-multipoint flows, we have to consider that all source nodes mark the traffic. Regarding the timing aspects of the methodology, RFC 8321 [RFC8321] already describes two contributions that are taken into account: the clock error between network devices and the network delay between measurement points. But we should now consider an additional contribution. Since all source nodes mark the traffic, the source measurement intervals can be of different lengths and with different offsets and this mismatch m can be added to d, as shown in figure. ...BBBBBBBBB | AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA | BBBBBBBBB... |<======================================>| | L | ...=========>|<==================><==================>|<==========... | L/2 L/2 | |<=><===>| |<===><=>| m d | | d m |<====================>| available counting interval Figure 5: Timing Aspects for Multipoint paths So the misalignment between the marking source routers gives an additional constraint and the value of m is added to d (that already includes clock error and network delay). In the end, the condition that must be satisfied to enable the method to function properly is that the available counting interval must be > 0, and that means: L - 2m - 2d > 0 for each measurement point on the multipoint path. Therefore, the mismatch between measurement intervals must satisfy this condition. Fioccola, et al. Expires May 9, 2019 [Page 13] Internet-Draft Multipoint AM November 2018 8. Multipoint Delay and Delay Variation The same line of reasoning can be applied to Delay and Delay Variation. It is important to highlight that both delay and delay variation measurements make sense in a multipoint path. The Delay Variation is calculated by considering the same packets selected for measuring the Delay. In general, it is possible to perform delay and delay variation measurements on multipoint paths basis or on single packets basis: o Delay measurements on multipoint paths basis means that the delay value is representative of an entire multipoint path (e.g. whole multipoint network, a cluster or a combination of clusters). o Delay measurements on single packets basis means that you can use multipoint path just to easily couple packets between inputs and output nodes of a multipoint path, as it is described in the following sections. 8.1. Delay measurements on multipoint paths basis 8.1.1. Single Marking measurement Mean delay and mean delay variation measurements can also be generalized to the case of multipoint flows. It is possible to compute the average one-way delay of packets, in one block, in a cluster or in the entire monitored network. The average latency can be measured as the difference between the weighted averages of the mean timestamps of the sets of output and input nodes. 8.2. Delay measurements on single packets basis 8.2.1. Single and Double Marking measurement Delay and delay variation measurements relative to only one picked packet per period (both single and double marked) can be performed in the Multipoint scenario with some limitations: Single marking based on the first/last packet of the interval would not work, because it would not be possible to agree on the first packet of the interval. Double marking or multiplexed marking would work, but each measurement would only give information about the delay of a single path. However, by repeating the measurement multiple Fioccola, et al. Expires May 9, 2019 [Page 14] Internet-Draft Multipoint AM November 2018 times, it is possible to get information about all the paths in the multipoint flow. This can be done in case of point-to- multipoint path but it is more difficult to achieve in case of multipoint-to-multipoint path because of the multiple source routers. if we would perform a delay measurement for more than one picked packet in the same marking period and, especially, if we want to get delay mesurements on multipoint-to-multipoint basis, both single and double marking method are not useful in the Multipoint scenario, since they would not be representative of the entire flow. The packets can follow different paths with various delays and in general it can be very difficult to recognize marked packets in a multipoint- to-multipoint path especially in case they are more than one per period. A desirable option is to monitor simultaneously all the paths of a multipoint path in the same marking period and, for this purpose, hashing can be used as reported in the next Section. 8.2.2. Hashing selection method RFC 5474 [RFC5474] and RFC 5475 [RFC5475] introduce sampling and filtering techniques for IP Packet Selection. The hash-based selection methodologies for delay measurement can work in a multipoint-to-multipoint path and can be used both coupled to mean delay or stand alone. [I-D.mizrahi-ippm-compact-alternate-marking] introduces how to use the Hash method combined with alternate marking method for point-to- point flows. It is also called Mixed Hashed Marking: the coupling of marking method and hashing technique is very useful because the marking batches anchor the samples selected with hashing and this simplifies the correlation of the hashing packets along the path. 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 sampled packets may vary considerably. For this reason the dynamic approach has been introduced for point-to-point flow in order to have the desired and almost fixed number of samples for each measurement period. In the hash-based sampling, alternate marking is used to create periods, so that hash-based samples are divided into batches, allowing to anchor the selected samples to their period. Moreover in the dynamic hash-based sampling, by dynamically adapting the length of the hash value, the number of samples is bounded in each marking period. This can be realized by choosing the maximum number of samples (NMAX) to be catched in a marking period. The algorithm Fioccola, et al. Expires May 9, 2019 [Page 15] Internet-Draft Multipoint AM November 2018 starts with only few hash bits, that permit to select a greater percentage of packets (e.g. with 0 bit 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 don't 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 behaviour is similar to point-to point flow. In particular, in the context of multipoint-to- multipoint flow, the dynamic hash could be the solution to perform delay measurements on specific packets and to overcome 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 both for point- to-point and for multipoint-to-multipoint flow. Then the longest hash used by MPs is deduced and it is applied to couple timestamps of same packets of 2 MPs of a point-to-point path or of 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 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 catched packet using the hash (in particular the "unused part of the hash" that should be different for each packet). In summary, the basic hash is logically similar to the double marking method, and in case of point-to-point path double marking and basic hash selection are equivalent. The dynamic approach scales the number of measurements per interval, and it would seem that double marking would also work well if we reduced the interval length, but this can be done only for point-to-point path and not for multipoint path, where we cannot couple the picked packets in a multipoint paths. So, in general, if we want to get delay mesurements on multipoint-to-multipoint path basis 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. Fioccola, et al. Expires May 9, 2019 [Page 16] Internet-Draft Multipoint AM November 2018 9. An SDN enabled Performance Management The Multipoint Alternate Marking framework that is introduced in this document adds flexibility to PM because it can reduce the order of magnitude of the packet counters. This allows an SDN Orchestrator to supervise, control and manage PM in large networks. The monitoring network can be considered as a whole or can be split in Clusters, that are the smallest subnetworks (group-to-group segments), maintaining the packet loss property for each subnetwork. They can also be combined in new connected subnetworks at different levels depending on the detail we want to achieve. An SDN Controller can calibrate Performance Measurements. It can start without examining in depth. In case of necessity (packet loss is measured or the delay is too high), the filtering criteria could be immediately specified more in order to perform a partition of the network by using Clusters and/or different combinations of Clusters. In this way the problem can be localized in a specific Cluster or in a single combination of Clusters and a more detailed analysis can be performed step-by-step by successive approximation up to a point-to- point flow detailed analysis. In addition an SDN Controller could also collect the measurement history. 10. Examples of application There are three application fields where it may be useful to take into consideration the Multipoint Alternate Marking: o VPN: The IP traffic is selected on IP source basis in both directions. At the end point WAN interface all the output traffic is counted in a single flow. The input traffic is composed by all the other flows aggregated for source address. So, by considering n end-points, the monitored flows are n (each flow with 1 ingress point and (n-1) egress points) instead of n*(n-1) flows (each flow, with 1 ingress point and 1 egress point); o Mobile Backhaul: LTE traffic is selected, in the Up direction, by the EnodeB source address and, in Down direction, by the EnodeB destination address because the packets are sent from the Mobile Packet Core to the EnodeB. So the monitored flow is only one per EnodeB in both directions; o OTT(Over The Top) services: The traffic is selected, in the Down direction by the source addresses of the packets sent by OTT Servers. In the opposite direction (Up) by the destination IP Fioccola, et al. Expires May 9, 2019 [Page 17] Internet-Draft Multipoint AM November 2018 addresses of the same Servers. So the monitoring is based on a single flow per OTT Servers in both directions. 11. Security Considerations This document specifies a method to perform measurements that does not directly affect Internet security nor applications that run on the Internet. However, implementation of this method must be mindful of security and privacy concerns, as explained in RFC 8321 [RFC8321]. 12. Acknowledgements The authors would like to thank Al Morton, Tal Mizrahi, Rachel Huang for the precious contribution. 13. IANA Considerations tbc 14. References 14.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/info/rfc2119>. [RFC5644] Stephan, E., Liang, L., and A. Morton, "IP Performance Metrics (IPPM): Spatial and Multicast", RFC 5644, DOI 10.17487/RFC5644, October 2009, <https://www.rfc-editor.org/info/rfc5644>. [RFC8321] Fioccola, G., Ed., Capello, A., Cociglio, M., Castaldelli, L., Chen, M., Zheng, L., Mirsky, G., and T. Mizrahi, "Alternate-Marking Method for Passive and Hybrid Performance Monitoring", RFC 8321, DOI 10.17487/RFC8321, January 2018, <https://www.rfc-editor.org/info/rfc8321>. 14.2. Informative References [I-D.amf-ippm-route] Alvarez-Hamelin, J., Morton, A., and J. Fabini, "Advanced Unidirectional Route Assessment", draft-amf-ippm-route-01 (work in progress), October 2017. Fioccola, et al. Expires May 9, 2019 [Page 18] Internet-Draft Multipoint AM November 2018 [I-D.mizrahi-ippm-compact-alternate-marking] Mizrahi, T., Arad, C., Fioccola, G., Cociglio, M., Chen, M., Zheng, L., and G. Mirsky, "Compact Alternate Marking Methods for Passive and Hybrid Performance Monitoring", draft-mizrahi-ippm-compact-alternate-marking-03 (work in progress), October 2018. [RFC5474] Duffield, N., Ed., Chiou, D., Claise, B., Greenberg, A., Grossglauser, M., and J. Rexford, "A Framework for Packet Selection and Reporting", RFC 5474, DOI 10.17487/RFC5474, March 2009, <https://www.rfc-editor.org/info/rfc5474>. [RFC5475] Zseby, T., Molina, M., Duffield, N., Niccolini, S., and F. Raspall, "Sampling and Filtering Techniques for IP Packet Selection", RFC 5475, DOI 10.17487/RFC5475, March 2009, <https://www.rfc-editor.org/info/rfc5475>. [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, <https://www.rfc-editor.org/info/rfc7011>. Authors' Addresses Giuseppe Fioccola (editor) Huawei Technologies Riesstrasse, 25 Munich 80992 Germany Email: firstname.lastname@example.org Mauro Cociglio Telecom Italia Via Reiss Romoli, 274 Torino 10148 Italy Email: email@example.com Fioccola, et al. Expires May 9, 2019 [Page 19] Internet-Draft Multipoint AM November 2018 Amedeo Sapio Politecnico di Torino Corso Duca degli Abruzzi, 24 Torino 10129 Italy Email: firstname.lastname@example.org Riccardo Sisto Politecnico di Torino Corso Duca degli Abruzzi, 24 Torino 10129 Italy Email: email@example.com Fioccola, et al. Expires May 9, 2019 [Page 20]