Subject: RE: [Pce] Comments requested on section 6.1.15draft-ietf-pce-comm-protocol-gen-reqs-01.txt

From: "Ash, Gerald R \(Jerry\), ALABS" <[email-masked]>
Date: Tue, 20 Sep 2005 17:47:15 -0500

JP, All,

> The DT is currently working hard to address the remaining issues  
> related to draft-ietf-pce-comm-protocol-gen-reqs-01.txt with the  
> objective to start a WG last call right after the publication 
> of this  next revision. There is in particular one section for
> which comments are very welcome: section 6.1.15 (Scalability).
> 
> Some of you asked for "indicative boundary numbers".
> 
> Considering the lack of deployments at that point, I personally
> think that providing numbers is a bit hazardous but we could I guess
> come up with rough estimates of what such numbers should be, based
> on our current set of expectations, while stressing the fact that
> PCE protocols should be designed for greater scalability. Thus such  
> numbers should be interpreted as "minimum values" (to be spelled out  
> in the document).
> 
> At this point, the following metrics have been proposed:
> 
>     (1) number of PCCs
>     (2) number of PCEs
>     (3) number of PCCs communicating with a single PCE
>     (4) number of PCEs communicated to by a single PCC
>     (5) number of PCEs communicated to by another PCE
>     (6) number of domains
>     (7) number of path requests per unit of time
>     (8) handling bursts of requests per unit of time
> 
> I would suggest to remove (1), (2) and (6) as they are not related
> to the PCEP (thus out of the scope of this requirement document).
> 
> Please let us know if you have any comment or disagreement with this  
> approach (preferably by Sept 23th).

Dimitri's original comment back in July
http://www1.ietf.org/mail-archive/web/pce/current/msg00272.html
suggested that 'boundary numbers' be specified for the items listed in
Section 6.1.15 (Scalability).  While I was skeptical (and still am) that
these boundary numbers could/should be specified (see
http://www1.ietf.org/mail-archive/web/pce/current/msg00273.html), it was
agreed at IETF-63 to include 'order-of-magnitude' values in the updated
draft.  This has been done in the submitted update (to be announced), as
follows:

"6.1.15 Scalability

   The PCECP MUST scale well, at least as good as linearly, with an
   increase of any of the following parameters (note, minimum order of
   magnitude estimates of what the PCECP should support are given in
   parenthesis):

   - number of PCCs (1000/domain)
   - number of PCEs (100/domain)
   - number of PCCs communicating with a single PCE (1000)
   - number of PCEs communicated to by a single PCC (100)
   - number of PCEs communicated to by another PCE (100)
   - number of domains (20)
   - number of path request messages (average of 10/second/PCE)
   - handling bursts of requests (burst of 100/second/PCE within a 10-
     second interval)."

IMO, all of these parameters relate directly or indirectly (as in the
case of #1, #2, and #6) to PCECP scalability.  My interpretation is that
the PCECP MUST support domains having these boundary numbers or larger.

Thanks,
Jerry

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---

From: JP Vasseur <[email-masked]>
Date: Tue, 20 Sep 2005 19:12:30 -0400

Hi Jerry,

On Sep 20, 2005, at 6:47 PM, Ash, Gerald R ((Jerry)), ALABS wrote:

> case of #1, #2, and #6) to PCECP scalability.

Ok let's take the example of (1). What really matters is the max  
number of PCC that a PCE should have a session with (metric 3) not  
the total number of PCCs. You could for instance have a total of 1000  
PCCs in a domain but no more than 100 PCCs communicating with a PCE.  
Why would the PCECP take of the total number of PCCs ? Same reasoning  
applies to (2) and (6).

> My interpretation is that

Good,

Others, please voice your opinion.

Thanks.

JP.