rfc9571v5.txt   rfc9571.txt 
Internet Engineering Task Force (IETF) S. Bryant, Ed. Internet Engineering Task Force (IETF) S. Bryant, Ed.
Request for Comments: 9571 Futurewei Technologies Inc. Request for Comments: 9571 University of Surrey
Category: Standards Track G. Swallow Category: Standards Track G. Swallow
ISSN: 2070-1721 Southend Technical Center ISSN: 2070-1721 Independent
M. Chen M. Chen
Huawei Huawei
G. Fioccola G. Fioccola
Huawei Technologies Huawei Technologies
G. Mirsky G. Mirsky
ZTE Corp. ZTE Corp.
May 2024 May 2024
Extension of RFC 6374-Based Performance Measurement Using Synonymous Extension of RFC 6374-Based Performance Measurement Using Synonymous
Flow Labels Flow Labels
skipping to change at line 415 skipping to change at line 415
characteristics: characteristics:
1. Number of packets in the batch (n) 1. Number of packets in the batch (n)
2. Sum of delays in a batch (S) 2. Sum of delays in a batch (S)
3. Maximum delay 3. Maximum delay
4. Minimum delay 4. Minimum delay
5. Sum of squares of inter-packet delay (SS) 5. Sum of squares of inter-packet delay (SumS)
Characteristics 1 and 2 give the mean delay. Measuring the delay of Characteristics 1 and 2 give the mean delay. Measuring the delay of
each pair in the batch is discussed in Section 7.3. each pair in the batch is discussed in Section 7.3.
Characteristics 3 and 4 give the outliers. Characteristics 3 and 4 give the outliers.
Characteristics 1, 2, and 5 can be used to calculate the variance of Characteristics 1, 2, and 5 can be used to calculate the variance of
the inter-packet gap, hence the standard deviation giving a view of the inter-packet gap, hence the standard deviation giving a view of
the distribution of packet delays and hence the jitter. The equation the distribution of packet delays and hence the jitter. The equation
for the variance (var) is given by: for the variance (var) is given by:
var = (SS - S*S/n)/(n-1) var = (SumS - S*S/n)/(n-1)
There is some concern over the use of this algorithm for measuring There is some concern over the use of this algorithm for measuring
variance because SS and S*S/n can be similar numbers, particularly variance because SumS and S*S/n can be similar numbers, particularly
where variance is low. However, the method is acceptable because it where variance is low. However, the method is acceptable because it
does not require a division in the hardware. does not require a division in the hardware.
7.2.1. Multi-packet Delay Measurement Message Format 7.2.1. Multi-packet Delay Measurement Message Format
The packet format of a Multi-packet Delay Measurement message is The packet format of a Multi-packet Delay Measurement message is
shown below: shown below:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
skipping to change at line 900 skipping to change at line 900
Huawei Huawei
Email: lizhenbin@huawei.com Email: lizhenbin@huawei.com
Siva Sivabalan Siva Sivabalan
Ciena Corporation Ciena Corporation
Email: ssivabal@ciena.com Email: ssivabal@ciena.com
Authors' Addresses Authors' Addresses
Stewart Bryant (editor) Stewart Bryant (editor)
Futurewei Technologies Inc. University of Surrey
Email: sb@stewartbryant.com Email: sb@stewartbryant.com
George Swallow George Swallow
Southend Technical Center Independent
Email: swallow.ietf@gmail.com Email: swallow.ietf@gmail.com
Mach(Guoyi) Chen Mach(Guoyi) Chen
Huawei Huawei
Email: mach.chen@huawei.com Email: mach.chen@huawei.com
Giuseppe Fioccola Giuseppe Fioccola
Huawei Technologies Huawei Technologies
Email: giuseppe.fioccola@huawei.com Email: giuseppe.fioccola@huawei.com
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