UDP Checksum Complement in the One-Way Active Measurement Protocol (OWAMP) and Two-Way Active Measurement Protocol (TWAMP)
draft-ietf-ippm-checksum-trailer-06
Technical Summary
In many IP measurement protocols, timestamps are required to calculate
packet transfer delay, and these timestamps occupy fields above the IP
layer. When implementers prefer to avoid the delay of stack processing,
it is preferred to insert the timestamps as close to the network
interface as possible, but this also requires maintaining sanity
among checksums and other integrity checks. This memo defines one way
to assign an optional field at the end of the UDP payload of test packets
to complement the timestamp and populate that field to keep checksum accuracy.
Working Group Summary
There has been sufficient review during 2 years of development,
and the comments were both constructive and supportive of this simple idea.
The draft can serve a useful purpose for the industry.
Document Quality
One chip vendor has implemented the procedure in the draft from a hardware
perspective, and another chip vendor has indicated their plans (privately)
to do the same. There are no known HW and SW implementations with TWAMP or
OWAMP at this time.
As far as expert reviews, there was sufficient review from the community
of TWAMP experts.
Personnel
Al Morton is Shepherd, Spencer Dawkins is AD.