draft-ietf-ippm-alt-mark-03.txt   draft-ietf-ippm-alt-mark-04.txt 
Network Working Group G. Fioccola, Ed. Network Working Group G. Fioccola, Ed.
Internet-Draft A. Capello, Ed. Internet-Draft A. Capello, Ed.
Intended status: Experimental M. Cociglio Intended status: Experimental M. Cociglio
Expires: August 12, 2017 L. Castaldelli Expires: September 2, 2017 L. Castaldelli
Telecom Italia Telecom Italia
M. Chen, Ed. M. Chen, Ed.
L. Zheng, Ed. L. Zheng, Ed.
Huawei Technologies Huawei Technologies
G. Mirsky, Ed. G. Mirsky, Ed.
ZTE ZTE
T. Mizrahi, Ed. T. Mizrahi, Ed.
Marvell Marvell
February 8, 2017 March 1, 2017
Alternate Marking method for passive performance monitoring Alternate Marking method for passive performance monitoring
draft-ietf-ippm-alt-mark-03 draft-ietf-ippm-alt-mark-04
Abstract Abstract
This document describes a passive method to perform packet loss, This document describes a passive method to perform packet loss,
delay and jitter measurements on live traffic. This method is based delay and jitter measurements on live traffic. This method is based
on Alternate Marking (Coloring) technique. A report on the on Alternate Marking (Coloring) technique. A report on the
operational experiment done at Telecom Italia is explained in order operational experiment done at Telecom Italia is explained in order
to give an example and show the method applicability. This technique to give an example and show the method applicability. This technique
can be applied in various situations as detailed in this document. can be applied in various situations as detailed in this document.
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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 http://datatracker.ietf.org/drafts/current/. Drafts is at http://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 August 12, 2017. This Internet-Draft will expire on September 2, 2017.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 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
(http://trustee.ietf.org/license-info) in effect on the date of (http://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
skipping to change at page 13, line 6 skipping to change at page 13, line 6
also possible to measure the two-way mean delay (round-trip delay). also possible to measure the two-way mean delay (round-trip delay).
3.2.2. Double marking methodology 3.2.2. Double marking methodology
The Single marking methodology for one-way delay measurement is The Single marking methodology for one-way delay measurement is
sensitive to out of order reception of packets. The first approach sensitive to out of order reception of packets. The first approach
to overcome this problem is described before and is based on the to overcome this problem is described before and is based on the
concept of mean delay. But the limitation of mean delay is that it concept of mean delay. But the limitation of mean delay is that it
doesn't give information about the delay values distribution for the doesn't give information about the delay values distribution for the
duration of the block. Additionally it may be useful to have not duration of the block. Additionally it may be useful to have not
only the mean delay but also the minimum and maximum delay values only the mean delay but also the minimum, maximum and median delay
and, in wider terms, to know more about the statistic distribution of values and, in wider terms, to know more about the statistic
delay values. So in order to have more information about the delay distribution of delay values. So in order to have more information
and to overcome out of order issues, a different approach can be about the delay and to overcome out of order issues, a different
introduced: it is based on double marking methodology. approach can be introduced: it is based on double marking
methodology.
Basically, the idea is to use the first marking to create the Basically, the idea is to use the first marking to create the
alternate flow and, within this colored flow, a second marking to alternate flow and, within this colored flow, a second marking to
select the packets for measuring delay/jitter. The first marking is select the packets for measuring delay/jitter. The first marking is
needed for packet loss and mean delay measurement. The second needed for packet loss and mean delay measurement. The second
marking creates a new set of marked packets that are fully identified marking creates a new set of marked packets that are fully identified
over the network, so that a network device can store the timestamps over the network, so that a network device can store the timestamps
of these packets; these timestamps can be compared with the of these packets; these timestamps can be compared with the
timestamps of the same packets on a second router to compute packet timestamps of the same packets on a second router to compute packet
delay values for each packet. The number of measurements can be delay values for each packet. The number of measurements can be
easily increased by changing the frequency of the second marking. easily increased by changing the frequency of the second marking.
But the frequency of the second marking must be not too high in order But the frequency of the second marking must be not too high in order
to avoid out of order issues. Between packets with the second to avoid out of order issues. Between packets with the second
marking there should be a security time gap (e.g. this gap could be, marking there should be a security time gap (e.g. this gap could be,
at the minimum, the mean network delay calculated with the previous at the minimum, the mean network delay calculated with the previous
methodology) to avoid out of order issues and also to have a number methodology) to avoid out of order issues and also to have a number
of measurement packets that is rate independent. If a second marking of measurement packets that is rate independent. If a second marking
packet is lost, the delay measurement for the considered block is packet is lost, the delay measurement for the considered block is
corrupted and should be discarded. corrupted and should be discarded.
Mean delay is calculated on all the packets of a batch and is a Mean delay is calculated on all the packets of a sample and is a
simple computation to be performed for single marking method. In simple computation to be performed for single marking method. In
some cases mean delay measure could not be enough when more delay some cases the mean delay measure is not sufficient to characterize
extent data are needed (e.g. minimum, maximum, variance and median the sample, and more statistics of delay extent data are needed, e.g.
delay values for each block). To overcome this drawback the idea is percentiles, variance and median delay values. The conventional
to couple the mean delay measure for the entire batch with double range (maximum-minimum) should be avoided for several reasons,
including stability of the maximum delay due to the influence by
outliers. RFC 5481 [RFC5481] section 6.5 highlights how the 99.9th
percentile of delay and delay variation is more helpful to
performance planners. To overcome this drawback the idea is to
couple the mean delay measure for the entire batch with double
marking method, where a subset of batch packets are selected for marking method, where a subset of batch packets are selected for
extensive delay calculation by using a second marking. In this way extensive delay calculation by using a second marking. In this way
it is possible to measure the minimum, the maximum, the variance and it is possible to perform a detailed analysis on these double marked
the median in order to perform a detailed analysis on these double packets. Please note that there are classic algorithms for median
marked packets. Please note that there are classic algorithms for and variance calculation, but are out of the scope of this document.
median and variance calculation, but are out of the scope of this The comparison between the mean delay for the entire batch and the
document. The comparison between the mean delay for the entire batch mean delay on these double marked packets gives an useful information
and the mean delay on these double marked packets gives an useful since it is possible to understand if the double marking measurements
information since it is possible to understand if the double marking are actually representative of the delay trends.
measurements are actually representative of the delay trends.
3.3. Delay variation measurement 3.3. Delay variation measurement
Similarly to one-way delay measurement (both for single marking and Similarly to one-way delay measurement (both for single marking and
double marking), the method can also be used to measure the inter- double marking), the method can also be used to measure the inter-
arrival jitter. We refer to the definition in RFC 3393 [RFC3393]. arrival jitter. We refer to the definition in RFC 3393 [RFC3393].
The alternation of colors, for single marking method, can be used as The alternation of colors, for single marking method, can be used as
a time reference to measure delay variations. In case of double a time reference to measure delay variations. In case of double
marking, the time reference is given by the second marked packets. marking, the time reference is given by the second marked packets.
Considering the example depicted in Figure 2, R1 stores a timestamp Considering the example depicted in Figure 2, R1 stores a timestamp
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[I-D.ietf-bier-pmmm-oam] [I-D.ietf-bier-pmmm-oam]
Mirsky, G., Zheng, L., Chen, M., and G. Fioccola, Mirsky, G., Zheng, L., Chen, M., and G. Fioccola,
"Performance Measurement (PM) with Marking Method in Bit "Performance Measurement (PM) with Marking Method in Bit
Index Explicit Replication (BIER) Layer", draft-ietf-bier- Index Explicit Replication (BIER) Layer", draft-ietf-bier-
pmmm-oam-01 (work in progress), January 2017. pmmm-oam-01 (work in progress), January 2017.
[I-D.ietf-mpls-flow-ident] [I-D.ietf-mpls-flow-ident]
Bryant, S., Pignataro, C., Chen, M., Li, Z., and G. Bryant, S., Pignataro, C., Chen, M., Li, Z., and G.
Mirsky, "MPLS Flow Identification Considerations", draft- Mirsky, "MPLS Flow Identification Considerations", draft-
ietf-mpls-flow-ident-03 (work in progress), January 2017. ietf-mpls-flow-ident-04 (work in progress), February 2017.
[I-D.ooamdt-rtgwg-oam-gap-analysis] [I-D.ooamdt-rtgwg-oam-gap-analysis]
Mirsky, G., Nordmark, E., Pignataro, C., Kumar, N., Kumar, Mirsky, G., Nordmark, E., Pignataro, C., Kumar, N., Kumar,
D., Chen, M., Yizhou, L., Mozes, D., Networks, J., and I. D., Chen, M., Yizhou, L., Mozes, D., Networks, J., and I.
Bagdonas, "Operations, Administration and Maintenance Bagdonas, "Operations, Administration and Maintenance
(OAM) for Overlay Networks: Gap Analysis", draft-ooamdt- (OAM) for Overlay Networks: Gap Analysis", draft-ooamdt-
rtgwg-oam-gap-analysis-02 (work in progress), July 2016. rtgwg-oam-gap-analysis-02 (work in progress), July 2016.
[I-D.ooamdt-rtgwg-ooam-requirement] [I-D.ooamdt-rtgwg-ooam-requirement]
Kumar, N., Pignataro, C., Kumar, D., Mirsky, G., Chen, M., Kumar, N., Pignataro, C., Kumar, D., Mirsky, G., Chen, M.,
Nordmark, E., Networks, J., and D. Mozes, "Overlay OAM Nordmark, E., Networks, J., and D. Mozes, "Overlay OAM
Requirements", draft-ooamdt-rtgwg-ooam-requirement-02 Requirements", draft-ooamdt-rtgwg-ooam-requirement-02
(work in progress), January 2017. (work in progress), January 2017.
[I-D.tempia-opsawg-p3m] [I-D.tempia-opsawg-p3m]
Capello, A., Cociglio, M., Castaldelli, L., and A. Bonda, Capello, A., Cociglio, M., Castaldelli, L., and A. Bonda,
"A packet based method for passive performance "A packet based method for passive performance
monitoring", draft-tempia-opsawg-p3m-04 (work in monitoring", draft-tempia-opsawg-p3m-04 (work in
progress), February 2014. progress), February 2014.
[RFC5481] Morton, A. and B. Claise, "Packet Delay Variation
Applicability Statement", RFC 5481, DOI 10.17487/RFC5481,
March 2009, <http://www.rfc-editor.org/info/rfc5481>.
[RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay [RFC6374] Frost, D. and S. Bryant, "Packet Loss and Delay
Measurement for MPLS Networks", RFC 6374, Measurement for MPLS Networks", RFC 6374,
DOI 10.17487/RFC6374, September 2011, DOI 10.17487/RFC6374, September 2011,
<http://www.rfc-editor.org/info/rfc6374>. <http://www.rfc-editor.org/info/rfc6374>.
[RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New [RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New
Performance Metric Development", BCP 170, RFC 6390, Performance Metric Development", BCP 170, RFC 6390,
DOI 10.17487/RFC6390, October 2011, DOI 10.17487/RFC6390, October 2011,
<http://www.rfc-editor.org/info/rfc6390>. <http://www.rfc-editor.org/info/rfc6390>.
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