Subject: [ippm] Comments on ITU-T IP Performance Work Status

From: "Fardid, Reza" <[email-masked]>
Date: Wed, 9 Mar 2005 10:13:17 -0800

Hi Al,

A have a number of comments on the Y.1541 loss performance objectives,
existing and new:

1.	Is there an ITU-T implementation report, e.g., from SPs that are
relying on the current IPLR objective of 10^(-3) for performance
management ?
2.	Is the new loss objective of 10^(-5) recommended for all QoS
classes, similar to the current recommendation, which does not
differentiate between real-time and best-effort services ?
3.	Is the new loss objective of 10^(-5) derived from empirical
evidence or some other methodology ?

These questions are relevant in the context of performance management,
which may be beyond the scope of IPPM. If so, then I appreciate your
off-list response.

Regards,

Reza Fardid

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From: Al Morton <[email-masked]>
Date: Wed, 09 Mar 2005 15:27:54 -0500

Hi Reza,

Let's take this off the list, because of scope and the fact that

ippm needs to focus on several in-scope topics.  But I'll

supply some quick answers below so that we don't leave everyone

hanging.  We have discussed this topic briefly on ippm-list in the
past.

If you're interested in this discussion, let Reza and me know.

Al

At 01:13 PM 03/09/2005, Fardid, Reza wrote:

A have a
number of comments on the Y.1541 loss performance objectives, existing
and new:

Is there an ITU-T implementation report, e.g., from SPs that are
relying on the current IPLR objective of 10^(-3) for performance
management ?

There's no formal report, just confirmation from several SPs

that they have put the current objectives to
use.

Is the new loss objective of 10^(-5)
recommended for all QoS classes, similar to the current recommendation,
which does not differentiate between real-time and best-effort services
?

The current 6 classes (five with loss < 10^-3) have been declared
"stable".

There are two new provisional classes with <10^-5
loss.

Is the new loss objective of 10^(-5)
derived from empirical evidence or some other methodology ?

Yes, we looked at requirements for digital video transport

(at various quality levels and positions in the distribution

hierarchy), for high capacity applications that use TCP, and

for various digital/TDM service emulations on packet networks.

Some of the above require Forward Error Correction, in addition

to the <10^-5 loss, in order to meet their objectives.

These
questions are relevant in the context of performance management, which
may be beyond the scope of IPPM. If so, then I appreciate your off-list
response.