Subject: [ippm] Internet delay model?

From: Doug Arnold <[email-masked]>
Date: Wed, 9 Jan 2002 16:21:22 -0800

Does anyone know of a model for one way delay variation, suitable for use in
simulation?  I am especially interested in the degree to which delays for
packets which traverse the same route are correlated in time (i.e., bursty).
If not a model how about some good data?

Thanks,

Doug Arnold

Chief Scientist
TrueTime, Inc.
3750 Westwind Blvd. Santa Rosa, CA  95403
t 707.636.1929  f 707.527.6640
[email-masked]  / www.truetime.com

---

From: "Alan Clark" <[email-masked]>
Date: Mon, 14 Jan 2002 09:07:49 -0500

Internet delay model?Doug

We have done some work in this area, taking two different approaches:

(i) NS-2 based simulation
Looking at the effects of bulk traffic on IP networks (e.g. MMPP for voice
and TCP data), particularly those networks with limited bandwidth access
connections (e.g. T1).

(ii) Measurements on Internet
Analyzing traces.

In both cases we do see strong correlation and fairly distinctive acf and
pdf.

We developed a time series model which exhibits similar statistical
properties to both simulation and captured results.  This uses an impulse
driven ARMA model and appears to be both easy to implement and calibrate.
We've been using the model to introduce PDV into VoIP packet streams in
order that we can verify the operation of our call quality estimation tool
(which incorporates a jitter buffer)

Regards

Alan Clark
Telchemy

  -----Original Message-----
  From: [email-masked] [mailto:[email-masked]]On Behalf Of
Doug Arnold
  Sent: Wednesday, January 09, 2002 7:21 PM
  To: [email-masked]'
  Subject: [ippm] Internet delay model?

  Does anyone know of a model for one way delay variation, suitable for use
in simulation?  I am especially interested in the degree to which delays for
packets which traverse the same route are correlated in time (i.e., bursty).
If not a model how about some good data?

  Thanks,

  Doug Arnold

  Chief Scientist
  TrueTime, Inc.