Subject: [ppsp] PM DIR review of draft-ietf-ppsp-base-tracker-protocol-03

From: Alan Clark <[email-masked]>
Date: Fri, 14 Feb 2014 17:04:33 -0500

This is a PM Directorate review of 
draft-ietf-ppsp-base-tracker-protocol-03 and is focused on the 
definition of metrics and the need for the use of RFC6390 templates.

This draft defines four metrics, onlineTime, uploadedBytes, 
downloadedBytes and availBandwidth. There is insufficient definition of 
these metrics and this draft SHOULD use RFC6390 templates to define these.
General comments:

(i) Online Time is defined as how long the peer has been in the P2P 
streaming system, expressed as an 8 bit value. It is not clear what the 
units are, or if it is intended that this is some form of enumerated value.

(ii) There does not appear to be a definition of the time window to 
which the uploaded and downloaded bytes relate. Do these relate to a 
specific file, in which case the file size should also be shown, or to 
an aggregate count, in which case the time window should be defined.

(iii) Uploaded/downloaded bytes could refer to layer 2/3 bytes or to 
content bytes. in the context of this draft it seems more likely that 
content bytes would be the parameter of interest however this should be 
specified.

(iv) “Available Bandwidth” has a very specific meaning and an associated 
set of measurement methodologies. Available bandwidth typically applies 
to the difference between raw network bandwidth and the current traffic 
level. Within a peer to peer network it seems likely that the intent is 
to report either the raw network access bandwidth for a node or the 
measured (effective) uploaded bit rate.

The definition of these metrics should be provided in RFC6390 form and 
should describe the units of measurement, the measurement interval, the 
measurement method and the intended application

Regards

Alan Clark

---

From: Qin Wu <[email-masked]>
Date: Sat, 15 Feb 2014 01:36:52 +0000

I agree with Alan's comments.
One comment to add:
I think The metric name "Available Bandwidth" needs to be more specific, "Available Bandwidth" is well defined in
draft-ietf-ospf-te-metric-extensions as link metric. "Available Bandwidth" defined in draft-ietf-ppsp-base-tracker-protocol-03
is only related to uploading bandwidth and can be difference between total uploading bandwidth and used uploading bandwidth.

Regards!
-Qin
-----Original Message-----
From: pm-dir [mailto:[email-masked]] On Behalf Of Alan Clark
Sent: Saturday, February 15, 2014 6:05 AM
To: [email-masked]; [email-masked]; [email-masked]; [email-masked]
Subject: [pm-dir] PM DIR review of draft-ietf-ppsp-base-tracker-protocol-03

(iv) "Available Bandwidth" has a very specific meaning and an associated 

Regards

Alan Clark

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