Liaison statement
The UDP Speed Test Protocol (UDPSTP) for One-Way IP Capacity Metric Measurement

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State Posted
Submitted Date 2026-05-26
From Groups bmwg, ippm
From Contact Mohamed Boucadair <mohamed.boucadair@orange.com>
To Group ITU-T-SG-12
To Contacts tsbsg12@itu.int
martin.adolph@itu.int
Cc Mohamed Boucadair <mohamed.boucadair@orange.com>
Mahesh Jethanandani <mjethanandani@gmail.com>
Ruediger Geib <Ruediger.Geib@telekom.de>
Scott Mansfield <Scott.Mansfield@Ericsson.com>
IP Performance Measurement Discussion List <ippm@ietf.org>
Thomas Graf <thomas.graf@swisscom.com>
Marcus Ihlar <marcus.ihlar@ericsson.com>
Response Contact Sarah Banks <sbanks@encrypted.net>
Giuseppe Fioccola <giuseppe.fioccola@huawei.com>
Marcus Ihlar <marcus.ihlar@ericsson.com>
Thomas Graf <thomas.graf@swisscom.com>
Technical Contact Ruediger Geib <Ruediger.Geib@telekom.de>
Purpose For information
Attachments (None)
Body 
The IP Performance Measurement (IPPM) Working Group is pleased to inform ITU-T
SG 12 about the publication of its work on “The UDP Speed Test Protocol
(UDPSTP) for One-Way IP Capacity Metric Measurement” as RFC 9946 (published in
Standards Track). The publication of this RFC is the latest achievement of the
effort to harmonize IP-Layer Capacity Metric and Method across standardization,
started by Al Morton.

Please note that RFC 9946 references ITU-T Recommendation Y.1540 on "Internet
protocol data communication service – IP packet transfer and availability
performance parameters" which is quoted as “providing the default [load rate
adjustment] algorithm [B] of UDPSTP”.

The IPPM Working Group appreciates the good coordination with ITU-T SG 12
related to IP Capacity Metric Measurement, in particular. Future coordinated
efforts between our two organizations on areas of joint interest are welcome.