Subject: RE: Qry on Traffic Policing

From: Andrew Smith <[email-masked]>
Date: Tue, 10 Jun 1997 13:16:51 -0700

We've also discussed in ISSLL using an IEEE 802.1p traffic class on LANs
to 
mark packets as "less-than Best Effort" for this purpose but no firm
proposals 
have come out yet.

A pointer to Dave Clark's (and others') papers would be helpful.

Andrew

***********************************************************************
Andrew Smith                            tel: +1 (408) 342-0985
Extreme Networks                        fax: +1 (408) 342-0990
1601 S. De Anza Blvd. #220              http://www.extremenetworks.com
Cupertino CA 95014                      em:  [email-masked]
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	----------
	From: 	Mark W Garrett[SMTP:[email-masked]]
	Sent: 	Tuesday, June 10, 1997 7:37 AM
	To: 	[email-masked]
	Cc: 	[email-masked]
	Subject: 	Re: Qry on Traffic Policing

	 > Policing will mark a flow's nonconformant packes so that they
may 
	 > not be involved in meeting service committments.        

	In IP, policing will cause nonconformant packets to be scheduled
	so they get "best effort" service (in the node where the
policing
	occurs), but there is no mechanism, I believe, to carry the
'mark'
	around with the packet.  Dave Clark had a paper last year on
this idea
	and some nice analysis and suggestions.  In ATM, such a marking
bit
	does exist (the CLP bit), and an IP-IS over ATM implementation
could
	use CLP marking in the ATM subnet based on IP-level policing.
Once
	you get out of the ATM cloud though, the "tag" is lost.

	I don't know whether there is an advantage or disadvantage to
policing
	once and "permanently" marking some packets as the
non-conforming
	ones, as opposed to policing/marking locally and separating
packets
	into conforming and non-conforming at each hop independently.

	-Mark

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	Mark W. Garrett         445 South St.
[email-masked]
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Fax: 201 829-2504
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ftp://ftp.bellcore.com/pub/mwg/homepage.html

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From: Juha Heinanen <[email-masked]>
Date: Wed, 11 Jun 1997 08:29:43 +0300

i would suggest to use the same coding in the ip tos field and in 802.1p
qos field so that there would be one-to-one mapping.  three service
classed might be adequate:  real time, guaranteed bandwidth, and best
effort.  the third bit could indicate the priority level within the
class.  that would give networks a change to implement qod without any
explicit resource reservation protocol.

-- juha

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From: Koskelainen Petri <[email-masked]>
Date: Wed, 11 Jun 1997 10:31:10 +0300 (EET DST)

> explicit resource reservation protocol.

Which IP version are you talking about ?

/petri

01 S. De Anza Blvd. #220              http://www.extremenetworks.com
 >Cupertino CA 95014                      em:  [email-masked]

 jon

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From: Wu-chang Feng <[email-masked]>
Date: Wed, 11 Jun 1997 09:10:35 -0400

>> A pointer to Dave Clark's (and others') papers would be helpful.

We've done some work which uses packet marking and an enhanced RED
queue to implement a controlled-load type of service.  (My apologies
if you've already received this msg through end2end)

-------

To: [email-masked]
Date: Thu, 22 May 1997 15:34:02 -0400
From: Wu-chang Feng <[email-masked]>

For those who are interested, I've placed our NOSSDAV'97 paper on
"Understanding TCP Dynamics in an Integrated Services Internet" at
http://www.eecs.umich.edu/~wuchang/ered/.  The ns mods and simulation
scripts used for this paper are also available there as is an extended
version of the paper.  The paper describes modifications to TCP to
exploit network reservations and an implementation of a
controlled-load service variant using an enhanced RED queue.

Wu