Subject: [PCN] Architecture terminology

From: <[email-masked]>
Date: Fri, 17 Oct 2008 11:35:39 +0100

I had a discussion with Steve and we're suggesting this as a way forward
to resolve the issues. 

Add the terms PCN-admissible-rate and PCN-supportable-rate as additional
terminology. Don't make wholesale text changes to the doc, but use these
terms in a few paragraphs. Then post these to the list, and ask for
comments.  So this is the post with the changes and the asking!

Thanks

Phil

S2 Terminology:

Add: PCN-admissible-rate: the rate of PCN-traffic on a link up to which
PCN admission control should accept new PCN-flows. 

Add: PCN-supportable-rate: the rate of PCN-traffic on a link down to
which PCN flow termination should, if necessary, terminate already
admitted PCN-flows.

S3: Benefits:

Bullet 2: change "The PCN-threshold-rate on each link can be chosen
small enough that admitted traffic can still be carried after a
rerouting in most failure cases" to "The PCN-admissible-rate on each
link can be chosen small enough that admitted traffic can still be
carried after a rerouting in most failure cases"

Bullet 9: change "The PCN-excess-rate may be set below the maximum rate
that PCN-traffic can be transmitted on a link..." to "The
PCN-supportable-rate may be set below the maximum rate that PCN-traffic
can be transmitted on a link..."

S4 Deployment scenarios:

In Figure 1, under "PCN-excess-rate" add "(=PCN-supportable-rate)" &
under "PCN-threshold-rate" add "(=PCN-admissible-rate)"

S6.1 Flow admission

Change the first para from:

The objective of PCN's flow admission control mechanism is to limit
   the PCN-traffic on each link in the PCN-domain to *roughly* its PCN-
   threshold-rate, by admitting or blocking prospective new flows, in
   order to protect the QoS of existing PCN-flows.  The PCN-threshold-
   rate is a parameter that can be configured by the operator and will
   be set lower than the traffic rate at which the link becomes
   congested and the node drops packets.
To:
The objective of PCN's flow admission control mechanism is to limit
   the PCN-traffic on each link in the PCN-domain to *roughly* its PCN-
   admissible-rate, by admitting or blocking prospective new flows, in
   order to protect the QoS of existing PCN-flows. With three encoding
states available, the PCN-threshold-
   rate is configured by the operator as equal to the
PCN-admissible-rate on each link. It is set lower than the traffic rate
at which the link becomes congested and the node drops packets. 
 
S6.2 Flow termination:

Change the first para from:

The objective of PCN's flow termination mechanism is to limit the
   PCN-traffic on each link to *roughly* its PCN-excess-rate, by
   terminating some existing PCN-flows, in order to protect the QoS of
   the remaining PCN-flows.  The PCN-excess-rate is a parameter that can
   be configured by the operator and may be set lower than the traffic
   rate at which the link becomes congested and the node drops packets.
To:
The objective of PCN's flow termination mechanism is to limit the
   PCN-traffic on each link to *roughly* its PCN-supportable-rate, by
   terminating some existing PCN-flows, in order to protect the QoS of
   the remaining PCN-flows.  With three encoding states available, the
PCN-excess-rate is configured by the operator as equal to the
PCN-supportable-rate on each link. It may be set lower than the traffic
   rate at which the link becomes congested and the node drops packets.
 
S6.3 Flow admission and/or flow termination when there are only two PCN
      encoding states:
3rd bullet, change:
o  both admission control and flow termination: only the excess-
      traffic-marking algorithm writes PCN-marks, however the configured
      rate (PCN-excess-rate) is set at the rate the admission control
      mechanism needs to limit PCN-traffic to, as shown in Figure 2.
To:
o  both admission control and flow termination: only the excess-
      traffic-marking algorithm writes PCN-marks, however the configured
      rate (PCN-excess-rate) is set equal to the PCN-admissible-rate, as
shown in Figure 2.
 
In Figure 2: 

under "U*PCN-excess-rate"  add "(=PCN-supportable-rate)" & under
"PCN-excess-rate" add "(=PCN-admissible-rate)"

_______________________________________________
PCN mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/pcn

---

From: "Geib, Ruediger" <[email-masked]>
Date: Fri, 17 Oct 2008 12:47:19 +0200

Phil,
 
allright with me.
 
Regards
 
Ruediger

  _____  

From: [email-masked] [mailto:[email-masked]] On Behalf Of [email-masked]
Sent: Friday, October 17, 2008 12:36 PM
To: [email-masked]
Subject: [PCN] Architecture terminology

I had a discussion with Steve and we're suggesting this as a way forward to resolve the issues. 

Add the terms PCN-admissible-rate and PCN-supportable-rate as additional terminology. Don't make wholesale text changes to the doc, but use these terms in a few paragraphs. Then post these to the list, and ask for comments.  So this is the post with the changes and the asking!

Thanks

Phil

S2 Terminology:

Add: PCN-admissible-rate: the rate of PCN-traffic on a link up to which PCN admission control should accept new PCN-flows. 

Add: PCN-supportable-rate: the rate of PCN-traffic on a link down to which PCN flow termination should, if necessary, terminate already admitted PCN-flows.

S3: Benefits:

Bullet 2: change "The PCN-threshold-rate on each link can be chosen small enough that admitted traffic can still be carried after a rerouting in most failure cases" to "The PCN-admissible-rate on each link can be chosen small enough that admitted traffic can still be carried after a rerouting in most failure cases"

Bullet 9: change "The PCN-excess-rate may be set below the maximum rate that PCN-traffic can be transmitted on a link..." to "The PCN-supportable-rate may be set below the maximum rate that PCN-traffic can be transmitted on a link..."

S4 Deployment scenarios:

In Figure 1, under "PCN-excess-rate" add "(=PCN-supportable-rate)" & under "PCN-threshold-rate" add "(=PCN-admissible-rate)"

S6.1 Flow admission

   order to protect the QoS of existing PCN-flows. With three encoding states available, the PCN-threshold-
   rate is configured by the operator as equal to the PCN-admissible-rate on each link. It is set lower than the traffic rate at which the link becomes congested and the node drops packets. 
 
S6.2 Flow termination:

   the remaining PCN-flows.  With three encoding states available, the PCN-excess-rate is configured by the operator as equal to the PCN-supportable-rate on each link. It may be set lower than the traffic
 
      rate (PCN-excess-rate) is set equal to the PCN-admissible-rate, as shown in Figure 2.
 
In Figure 2: 

under "U*PCN-excess-rate"  add "(=PCN-supportable-rate)" & under "PCN-excess-rate" add "(=PCN-admissible-rate)"

---

From: "Ingemar Johansson S" <[email-masked]>
Date: Fri, 17 Oct 2008 13:00:21 +0200

Hi
 
I believe that the terms PCN-admissible-rate and PCN-supportable-rate
much better explains what it is all about.
 
/Ingemar

________________________________

	From: [email-masked] [mailto:[email-masked]] On
Behalf Of [email-masked]
	Sent: den 17 oktober 2008 12:36
	To: [email-masked]
	Subject: [PCN] Architecture terminology

	I had a discussion with Steve and we're suggesting this as a way
forward to resolve the issues. 

	Add the terms PCN-admissible-rate and PCN-supportable-rate as
additional terminology. Don't make wholesale text changes to the doc,
but use these terms in a few paragraphs. Then post these to the list,
and ask for comments.  So this is the post with the changes and the
asking!

	Thanks

	Phil

	S2 Terminology:

	Add: PCN-admissible-rate: the rate of PCN-traffic on a link up
to which PCN admission control should accept new PCN-flows. 

	Add: PCN-supportable-rate: the rate of PCN-traffic on a link
down to which PCN flow termination should, if necessary, terminate
already admitted PCN-flows.

	S3: Benefits:

	Bullet 2: change "The PCN-threshold-rate on each link can be
chosen small enough that admitted traffic can still be carried after a
rerouting in most failure cases" to "The PCN-admissible-rate on each
link can be chosen small enough that admitted traffic can still be
carried after a rerouting in most failure cases"

	Bullet 9: change "The PCN-excess-rate may be set below the
maximum rate that PCN-traffic can be transmitted on a link..." to "The
PCN-supportable-rate may be set below the maximum rate that PCN-traffic
can be transmitted on a link..."

	S4 Deployment scenarios:

	In Figure 1, under "PCN-excess-rate" add
"(=PCN-supportable-rate)" & under "PCN-threshold-rate" add
"(=PCN-admissible-rate)"

	S6.1 Flow admission

	The objective of PCN's flow admission control mechanism is to
limit
	   the PCN-traffic on each link in the PCN-domain to *roughly*
its PCN-
	   threshold-rate, by admitting or blocking prospective new
flows, in
	   order to protect the QoS of existing PCN-flows.  The
PCN-threshold-
	   rate is a parameter that can be configured by the operator
and will
	   be set lower than the traffic rate at which the link becomes
	   congested and the node drops packets.
	To:
	The objective of PCN's flow admission control mechanism is to
limit
	   the PCN-traffic on each link in the PCN-domain to *roughly*
its PCN-
	   admissible-rate, by admitting or blocking prospective new
flows, in
	   order to protect the QoS of existing PCN-flows. With three
encoding states available, the PCN-threshold-
	   rate is configured by the operator as equal to the
PCN-admissible-rate on each link. It is set lower than the traffic rate
at which the link becomes congested and the node drops packets. 
	 
	S6.2 Flow termination:

	The objective of PCN's flow termination mechanism is to limit
the
	   PCN-traffic on each link to *roughly* its PCN-excess-rate, by
	   terminating some existing PCN-flows, in order to protect the
QoS of
	   the remaining PCN-flows.  The PCN-excess-rate is a parameter
that can
	   be configured by the operator and may be set lower than the
traffic
	   rate at which the link becomes congested and the node drops
packets.
	To:
	The objective of PCN's flow termination mechanism is to limit
the
	   PCN-traffic on each link to *roughly* its
PCN-supportable-rate, by
	   terminating some existing PCN-flows, in order to protect the
QoS of
	   the remaining PCN-flows.  With three encoding states
available, the PCN-excess-rate is configured by the operator as equal to
the PCN-supportable-rate on each link. It may be set lower than the
traffic
	   rate at which the link becomes congested and the node drops
packets.
	 
	S6.3 Flow admission and/or flow termination when there are only
two PCN
	      encoding states:
	3rd bullet, change:
	o  both admission control and flow termination: only the excess-
	      traffic-marking algorithm writes PCN-marks, however the
configured
	      rate (PCN-excess-rate) is set at the rate the admission
control
	      mechanism needs to limit PCN-traffic to, as shown in
Figure 2.
	To:
	o  both admission control and flow termination: only the excess-
	      traffic-marking algorithm writes PCN-marks, however the
configured
	      rate (PCN-excess-rate) is set equal to the
PCN-admissible-rate, as shown in Figure 2.
	 
	In Figure 2:

---

From: Michael Menth <[email-masked]>
Date: Fri, 17 Oct 2008 13:19:20 +0200

Hi Phil,

thanks a lot!

Regards,

Michael

[email-masked] wrote:
>
> I had a discussion with Steve and we’re suggesting this as a way 
> additional terminology. Don’t make wholesale text changes to the doc, 
> and ask for comments. So this is the post with the changes and the asking!
>
> Thanks
>
> Phil
>
> S2 Terminology:
>
> Add: PCN-admissible-rate: the rate of PCN-traffic on a link up to 
> which PCN admission control should accept new PCN-flows.
>
> Bullet 2: change “The PCN-threshold-rate on each link can be chosen 
> rerouting in most failure cases” to “The PCN-admissible-rate on each 
> carried after a rerouting in most failure cases”
>
> Bullet 9: change “The PCN-excess-rate may be set below the maximum 
> rate that PCN-traffic can be transmitted on a link…” to “The 
> PCN-supportable-rate may be set below the maximum rate that 
> PCN-traffic can be transmitted on a link…”
>
> S4 Deployment scenarios:
>
> In Figure 1, under “PCN-excess-rate” add “(=PCN-supportable-rate)” & 
> under “PCN-threshold-rate” add “(=PCN-admissible-rate)”
>
> S6.1 Flow admission
>
> 3^rd  bullet, change:
> under “U*PCN-excess-rate” add “(=PCN-supportable-rate)” & under 
> “PCN-excess-rate” add “(=PCN-admissible-rate)”
>
> ------------------------------------------------------------------------
>

-- 
Dr. Michael Menth, Assistant Professor
University of Wuerzburg, Institute of Computer Science
Am Hubland, D-97074 Wuerzburg, Germany, room B206
phone: (+49)-931/888-6644, fax: (+49)-931/888-6632
mailto:[email-masked]
http://www3.informatik.uni-wuerzburg.de/research/ngn

---

From: <[email-masked]>
Date: Fri, 17 Oct 2008 13:47:56 +0100

Firstly the changes are OK with me.

I think perhaps this whole debate highlights (and is symptomatic of)
something that Michael was getting at in his earlier email thread
relating to the marking draft. To summarise that thread:

PCN consists of 3 core ideas: methods of metering and marking packets,
methods to convey those marks and a way to join all the pieces into a
coherent whole in a given system (designed for a given deployment
scenario). All these need separate documents. Over the top of all that
lies the PCN architecture document which sets out an overall framework
into which all the pieces have to fit.

I think much of the current debate stems from the architecture document
having to describe both an overall framework but also having to include
at least some guidance on how to integrate all the pieces. It is this
integration part that leads to the discussion between which terminology
is best...

Toby

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Michael Menth
Sent: 17 October 2008 12:19
To: Eardley,PL,Philip,CXR9 R
Cc: pcn
Subject: Re: [PCN] Architecture terminology

Hi Phil,

thanks a lot!

Regards,

Michael

asking!
> Bullet 9: change "The PCN-excess-rate may be set below the maximum 
> rate that PCN-traffic can be transmitted on a link..." to "The 
> PCN-traffic can be transmitted on a link..."
>
> S4 Deployment scenarios:
>
packets.
packets.
configured
configured

---

From: Tom Taylor <[email-masked]>
Date: Sun, 19 Oct 2008 22:49:11 -0400

... and I'll join the chorus of agreement.