Re: Substrate Resouces

Perhaps I’m a bit confused by the word “sliceable”, but my sense is that this word is interchangeable with “multiplexable”. If so, then there are several ways of multiplexing a resource. When it comes to CPUs, we think of time division multiplexing to get virtual CPUs. When it comes to fibers, I think we can think of not only time division multiplexing (TDM) but also frequency/wavelength division multiplexing (FDM/WDM) and space division multiplexing (SDM). A simple example of SDM is that we might partition the network into multiple pieces for use by multiple experiments. These partitions may be dynamic based on what experiments are being run at any time. Am I off in the weeds?

 

Drew

 

Drew Perkins Chief Technology Officer   Infinera Corporation 169 Java Drive Sunnyvale, CA, 94089   Direct:  (408) 572-5308 Fax:     (408) 904-4644 Mobile: (408) 666-1686 dperkins@... http://www.infinera.com

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-----Original Message-----
From: substrate-wg-bounces@... [mailto:substrate-wg-bounces@...] On Behalf Of John Jacob
Sent: Friday, November 02, 2007 6:38 AM
To: substrate-wg@...
Subject: Re: [substrate-wg] Substrate Resouces

 

Stu,

 

You made some good points and raised good questions. I would like to

know how others on this list feel about this. As a point of

clarification, the selection of physical/logical/synthetic in the

current version was primarily to stimulate discussion. It is quite

likely that several of these assignments are confusing or incorrect. I

will incorporate your input into the master version to be redistributed

after the initial wave of discussions.

 

Thanks,

John

 

 

 

stuart.d.elby@... wrote:

> John,

> 

> I have the same question; I am not sure what the boundary is between

> physical and logical as a result of sliceability.  Building on

> Masanori's example, ff a network element has a CPU running routing

> protocol stacks and those processing threads can be partitioned into

> virtual router threads, then I have the basis for virtual routing

> functions (VRFs) which are logical routers built by 'slicing' a physical

> CPU. Is this what you were thinking when you labeled the columns?

> 

> Another observation is that you have labeled 'Ports' as logical

> constructs.  I do agree that this is a very important type of port we

> need to consider, but let's not loose sight of the physical (e.g. 100G)

> ports that will be used to connect these platforms to the underlying

> fiber facilities. I suggest that we consider "line cards" and "switch

> ports" physical entities, and "logical (switch) ports" logical entities

> to avoid confusion. The physical binding of a switch port "a" to a fiber

> facility to a switch port "b" would be a "physical circuit" or

> "connection". All other bindings of logical ports would be "synthetic"

> paths as you have already defined.

> 

> -Stu

> 

> -----Original Message-----

> From: substrate-wg-bounces@...

> [mailto:substrate-wg-bounces@...] On Behalf Of Masanori Takashima

> Sent: Friday, November 02, 2007 12:57 AM

> To: John Jacob

> Cc: substrate-wg@...

> Subject: Re: [substrate-wg] Substrate Resouces

> 

> Hi, John,

> 

> Let me know what do you mean by Sliceable at column F.

> 

> I guess that Sliceable means that whatever an entry in column B consists

> of a set of finer grained resources. For example, CPU is Sliceable

> because CPU consists of a set of CPU usage, where CPU usage is a

> resource.

> 

> Best regards,

> Masanori

> 

> 

> 

> _______________________________________________

> substrate-wg mailing list

> substrate-wg@...

> http://lists.geni.net/mailman/listinfo/substrate-wg

> 

>  

 

 

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