Method, a computer program product, and a carrier for indicating one-way latency in a data network
AssigneeAccedian Networks Inc.
InventorsKjell Hansson, Olof Hagsand
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Abstract
Disclosed herein is a method, a computer program product, and a carrier for indicating one-way latency in a data network (N) between a first node (A) and a second node (B), wherein the data network (N) lacks continuous clock synchronization, comprising: a pre-synchronisation step, a measuring step, a post-synchronisation step, an interpolation step, and generating a latency profile. The present invention also relates to a computer program product incorporating the method, a carrier comprising the computer program product, and a method for indicating server functionality based on the first aspect.
Claims8
A method for determining one-way latency between a first computer node (A) having a first clock and a second computer node (B) having a second clock, comprising:
- pre-synchronizing said first clock of said first computer node (A) with said second clock of said second computer node (B),
- said pre-synchronizing further comprising obtaining a first clock difference value and a first absolute clock value;
- measuring a sending time and a receiving time associated with each measurement message within a plurality of measurement messages;
- post-synchronizing said first clock of said first computer node (A) with said second clock of said second computer node (B),
- said post-synchronizing further comprising obtaining a second clock difference value and a second absolute clock value;
- interpolating, comprising
- adjusting the sending time associated with each measurement message,
- said adjusting based on
- the sending time,
- the said first and second clock difference values, and
- the said first and second absolute clock values,
- further wherein said adjusting comprises calculating a ratebias,
- said calculating of ratebias comprising calculating a numberator=(CDIFF1−CDIFF0) wherein
- CDIFF1 is the second clock difference value, and
- CDIFF0 is the first clock difference value,
- calculating the one-way latency associated with a measurement message in the data network between said first computer node (A) and said second computer node (B) as the difference between
- the receiving time associated with the measurement message, and
- the adjusted sending time associated with the measurement message;
- and
- generating a latency profile.
A method for generating a one-way latency profile between a first computer node (A) having a first clock and a different second computer node (B) having a second clock, located in a data network without continuous clock synchronization, comprising:
- pre-synchronizing said first clock of said first computer node (A) with said second clock of said second computer node (B) to
- generate pre-synchronization values representing one or more absolute clock values and one or more clock difference values, and
- obtain a first absolute clock value and a first clock difference value from said one or more absolute clock values and one or more clock difference values,
- said pre-synchronizing carried out using a plurality of synchronization request and synchronization response messages;
- following said pre-synchronizing, collecting a predetermined number of time measurements, using a plurality of measurement messages;
- following said collecting, post-synchronizing said first clock of said first computer node (A) with said second clock of said second computer node (B) to
- generate post-synchronization values representing one or more absolute clock values and one or more clock difference values, and
- obtain a second absolute clock value and a second clock difference value from said one or more absolute clock values and one or more clock difference values,
- said post-synchronizing carried out using a plurality of synchronization request and synchronization response messages;
- interpolating said plurality of time measurements to create a predetermined number of latency measurements,
- said interpolating comprising adjusting said time measurements using said first and second absolute clock values and said first and second clock difference values,
- wherein said adjusting comprises calculating a ratebias;
- and
- said calculating of ratebias comprising calculating a numberator=(CDIFF1−CDIFF0) wherein
- CDIFF1 is the second clock difference value, and
- CDIFF0 is the first clock difference value,
- generating said one-way latency profile based on said latency measurements.
Dependencies are inferred from the claim text.