Subject: RE: [ippm] 'bursty loss' metrics

From: [email-masked]
Date: Wed, 5 Dec 2001 16:24:19 +0200

Hello,
 
you could also take a look at ETSI EP TIPHON document TS 101 329-5 at
http://www.etsi.org/tiphon <http://www.etsi.org/tiphon> . Effect of
burstiness and means of measuring that have been addressed there.
 
    Vilho

-----Original Message-----
From: ext Haim Zlotokrilov [mailto:[email-masked]]
Sent: 05 December 2001 15:51
To: [email-masked]'
Subject: [ippm] 'bursty loss' metrics

Hi 
I'm doing a research about IP QoS for VoIP application, especially regarding
the influence of bursty vs. random packet  loss and its effect on perceived
quality.

Therefore I'm interested in definitions of 'loss burstiness'. Are there any
ideas other than those mentioned in "One-way Loss Pattern Sample Metrics"? 

The 'm out of n' metrics was mentioned, but not in details. Can anyone
explain more about this metrics? 

Best Regards 
Zlatokrilov Haim

---

From: "Alan Clark" <[email-masked]>
Date: Thu, 6 Dec 2001 12:40:09 -0500

'bursty loss' metricsThe algorithm described in TS  101 329-5 (VQmon) is
described in an IPtel 2001 paper and in a number of standards
contributions - these are collected together on
(http://www.telchemy.com/techref.html).

The key issues to consider when looking at burst packet loss effects are:-

(i) Isolated lost packets are generally masked by packet loss concealment
algorithms

(ii) Periods of high packet loss are generally more noticeable to the
listener

(iii) At low average loss rates burst packet loss can sound better as there
are long gaps between bursts

(iv) At high average loss rates burst packet loss generally results in a
lower subjective score

(v) There are "time constants" associated with periods of poor quality, e.g.
the longer a period of poor quality persists then the more annoyed a
listener becomes, after the period of poor quality ends then it takes some
time for the listener to forgive (or forget)

(vi) There appears to be a recency effect which results in lower subjective
scores for calls with bursts of packet loss near the end .. a test by AT&T
showed a reduction in MOS of 0.6 due to this effect.

Alan

  -----Original Message-----
  From: [email-masked] [mailto:[email-masked]]On Behalf Of
[email-masked]
  Sent: Wednesday, December 05, 2001 9:24 AM
  To: [email-masked]; [email-masked]
  Cc: [email-masked]
  Subject: RE: [ippm] 'bursty loss' metrics

  Hello,

  you could also take a look at ETSI EP TIPHON document TS 101 329-5 at
http://www.etsi.org/tiphon. Effect of burstiness and means of measuring that
have been addressed there.

      Vilho
    -----Original Message-----
    From: ext Haim Zlotokrilov [mailto:[email-masked]]
    Sent: 05 December 2001 15:51
    To: [email-masked]'
    Subject: [ippm] 'bursty loss' metrics

    Hi
    I'm doing a research about IP QoS for VoIP application, especially
regarding the influence of bursty vs. random packet  loss and its effect on
perceived quality.

    Therefore I'm interested in definitions of 'loss burstiness'. Are there
any ideas other than those mentioned in "One-way Loss Pattern Sample
Metrics"?

    Best Regards
    Zlatokrilov Haim