Subject: Lost attributes DSQueuePriority and DSDropPriority

From: [email-masked]
Date: Mon, 02 Nov 1998 18:08:26 -0500

The following is being forwarded to the policy mailing list.
Message originally sent by Mark Stevens <[email-masked]>
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Two useful attributes associated with a DiffServPolicyAction,
included in the previous version made available at the DEN web
site, were dropped. These attributes are DSQueuePriority and
DSDropPriority. They permitted using a subset of the the diffserv
schema to express certain simple policies. This is no longer
quite so easy to do, if it is even possible.

I am not sure where we would include such attributes in the new
structure and I cannot see how to map values for the old
attributes into attributes found in the new structure.

Regards,

Mark Stevens
Lucent Technoliges
Concord Technology Center
300 Baker Avenue
Concord, MA   01742

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From: [email-masked]
Date: Mon, 02 Nov 1998 18:37:14 +0000

The following is being forwarded to the policy mailing list.
Message originally sent by Raju Rajan <[email-masked]>
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> DSDropPriority. 

The DSLossParameter attribute was supposed to replace the DSDropPriority,
allowing each enforcement entity to map the absolute loss values to whatever
priority classes or queues it wished. It is straightforward to translate the
absolute values into relative preferences, and the attribute is implementation
dependent, anyway. (To make it precise we would have to state the number of
packets over which the loss ratio had to be measured and maintained. It was
regarded too onerous for DiffServ requirements).

The QueuePriority was thought to be redundant with the DelayParameter, ie, what
does it mean to have a better queue priority but a higher delay (and maybe
greater loss)? In order to avoid this ambiguity, we stuck to a set of attributes
that could be unambiguously interpreted. (In our implementation, we use the
relative delay format to express queueing preferences, for instance.)
Jean-Christophe pointed out the redundancy initially, and unless there is
compelling argument refuting it, his view seems to make sense

They permitted using a subset of the the diffserv
> attributes into attributes found in the new structure.

I could elaborate, if the mapping is still not clear. Hope this helps,

Regards,

Raju Rajan