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Re: [RPRWG] RPR Perf: Metrics for Phase I



Harry,
 
That is the intent.
Thanks for rewording it to remove the ambiguity which I was not aware of.
 
Khaled Amer
President, AmerNet Inc.
Architecture Analysis and Performance Modeling Specialists
Address:     13711 Solitaire Way, Irvine, CA 92620
Phone:        (949)552-1114                      Fax:     (949)552-1116           
e-mail:         khaledamer@xxxxxxx          
Web:           www.performancemodeling.com
 

 
----- Original Message -----
From: Harry Peng
Sent: Tuesday, April 24, 2001 7:41 AM
Subject: RE: [RPRWG] RPR Perf: Metrics for Phase I

 
Khaled,
 
The ambiguous part still lies in the conversation path. The hub node can sink 200% and source 200% because it is connected to 2 rings.
I'm not adding both transmits and receive into the traffic load number.
Whether the hub can process all the traffic (200% each direction) is outside the scope of the MAC.
e.g. The hub can source 200% on both rings, each talk to 1/2 the station. This is a spatial reuse property.
 
 
 
Proposal:
 
In the hub application:
There are 16 stations, 1 to 16 like a hex clock. Station 16 is the Hub. Stations 1 to 15 all send traffic to station 16 on the same ring e.g. in the clockwise ring
    Sum of all station traffic is 200% of link (10G)  capacity all turned on at time T1.
    Traffic source from each station is 1.3G each, destination is the hub.
   
 
Regards,
 
 
Harry
 
 
-----Original Message-----
From: Khaled Amer [mailto:khaledamer@xxxxxxx]
Sent: Saturday, April 21, 2001 1:15 AM
To: Peng, Harry [SKY:1E11:EXCH]; Reflector RPRWG
Subject: Re: [RPRWG] RPR Perf: Metrics for Phase I

Harry,
 
Thanks for pointing out this ambiguity.
We had discussed that overcapacity would mean 200%. This should be added to the chart.
 
Now, the question becomes if that would mean that the hub generates 100% capacity and receives 100%?
I suggest that the answer is NO.
The reason is that this would not be over capacity since we're using dual rings. This would only be considered over capacity if we're using one ring.
 
So, for dual rings (as in the charts), we should have the hub generate 200% the ring capacity (i.e. 20Gbps is running a 10Gbps ring), and also receive 200% of the ring capacity generated by the other nodes.
 
Does this help clarify the ambiguity?
Any discussions or suggestions?
 
 
Khaled Amer
President, AmerNet Inc.
Architecture Analysis and Performance Modeling Specialists
Address:     13711 Solitaire Way, Irvine, CA 92620
Phone:        (949)552-1114                      Fax:     (949)552-1116           
e-mail:         khaledamer@xxxxxxx          
Web:           www.performancemodeling.com
 

 
----- Original Message -----
From: Harry Peng
Sent: Friday, April 20, 2001 6:24 AM
Subject: RE: [RPRWG] RPR Perf: Metrics for Phase I

Khaled:
 
I'm not clear as to the conversations (source to destination) profile on the ring as outlined on page 22 of the attached document.
How is the ring over capacity?
and what is the overcapacity number? 150%, 200%...
 
 
Regards,
 
 
Harry
-----Original Message-----
From: Khaled Amer [mailto:khaledamer@xxxxxxx]
Sent: Wednesday, April 18, 2001 12:23 AM
To: Reflector RPRWG
Subject: [RPRWG] RPR Perf: Metrics for Phase I

All,
 
I've been getting questions about Phase I of the performance modeling and what's included.
Throughout the work of the ad-hoc group we came to an agreement to these metrics and parameters.
We've been trying to put it in a document, but it got into too much details related to headers, signals and interfaces which hindered its progress.
 
In my opinion, based on several years of performance modeling as a career, all what is needed is in the attached presentation. There are some minor points that are left open which provide us with some flexibility.
 
Please use this as a guideline for your performance modeling efforts.
If you have any questions or concerns, please don't hesitate to let me know.
 
Khaled Amer
President, AmerNet Inc.
Architecture Analysis and Performance Modeling Specialists
Address:     13711 Solitaire Way, Irvine, CA 92620
Phone:        (949)552-1114                      Fax:     (949)552-1116           
e-mail:         khaledamer@xxxxxxx          
Web:           www.performancemodeling.com