Subject: [PCN] "blind marking" not a big advantage

From: Michael Menth <[email-masked]>
Date: Mon, 25 Feb 2008 11:32:03 +0100

Hi,

I have seen that some encoding discussions underlined the benefit of 
"blind marking", i.e. the codepoint can be set without reading the ECN 
bits before. I just want to point out that this advantage is not so big 
because the meter needs to know the marking anyway to avoid that 
termination marked packets are metered. I just copied from the 
comparison draft 
http://www.ietf.org/internet-drafts/draft-charny-pcn-comparison-00.txt

   |-------------------------------------------------------------------|
   |Metering and  | do not meter  |  meter all pkts  | do not meter    |
   |remarking of  | AM-marked     |  for admission   | TM-marked pkts  |
   |previously    | packets       |  and termination;| for termination |
   |marked        |               |  do not re-mark  | meter all pkts;|
   |packets       |               |  TM-marked pkts  | for admission,  |
   |              |               |                  | do not re-mark  |
   |              |               |                  | TM-marked pkts  |
   |-------------------------------------------------------------------|

Regards,

    Michael

-- 
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

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---

From: <[email-masked]>
Date: Mon, 25 Feb 2008 11:33:27 -0000

In terms of 3SM edge behaviour [the 3rd of the 4 columns below), then
termination marked packets are metered.

For CL edge behaviour [the 4th of the 4 columns below), then including
termination marked packets can lead to over-termination in multiple
bottleneck scenarios. 
Possibly this is a trade-off work making? Ie simpler behaviour for
PCN-interior-node for more complexity in edges or more uncertainty in
outcome of termination?

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf Of
> Michael Menth
> Sent: 25 February 2008 10:32
> To: pcn
> Subject: [PCN] "blind marking" not a big advantage
> 
> Hi,
> 
>    |              |               |                  | do not re-mark
|
>    |              |               |                  | TM-marked pkts
|

---

From: Michael Menth <[email-masked]>
Date: Mon, 25 Feb 2008 14:07:23 +0100

Hi Phil,

yes, this issue boils down to the tradeoff implementation complexity vs. 
overtermination in multiple bottleneck scenarios.

I can try to quantify the overtermination in future performance studies. 
Likewise, it would be good to have input from manufacturers about the 
complexity increase when going from "blind marking" to "stateful marking".

Regards,

    Michael

[email-masked] wrote:
>> bits before. I just want to point out that this advantage is not so
>>     
> big
>   
>>    |Metering and  | do not meter  |  meter all pkts  | do not meter
>>     
> |
>   
>>    |remarking of  | AM-marked     |  for admission   | TM-marked pkts
>>     
> |
>   
>>    |previously    | packets       |  and termination;| for termination
>>     
> |
>   
>>    |marked        |               |  do not re-mark  | meter all
>>     
> pkts;|
>   
>>    |packets       |               |  TM-marked pkts  | for admission,
>>     
> |
>   
>>    |              |               |                  | do not re-mark
>>     
> |
>   
>>    |              |               |                  | TM-marked pkts
>>     
> |
>

---

From: "Anurag Bhargava" <[email-masked]>
Date: Mon, 25 Feb 2008 11:07:54 -0600

http://www.ietf.org/proceedings/staging/draft-westberg-pcn-load-control-
03.txt

BR,
-Anurag Bhargava

---

From: "Anurag Bhargava" <[email-masked]>
Date: Mon, 25 Feb 2008 11:58:06 -0600

FYI,

http://www.ietf.org/internet-drafts/draft-westberg-pcn-load-control-03.t
xt

-Anurag Bhargava

>From: [email-masked] [mailto:[email-masked]] On 
>Behalf Of Anurag Bhargava
>Sent: Monday, February 25, 2008 12:08 PM
>To: [email-masked]
>Subject: [PCN] LC-PCN version 03 uploaded
>