Re: question on draft-lfblb-draft.txt?

My assumption to date has been that l2 frame 
processing is closely coupled to the media, and belongs in the Port LFB.
But I could be wrong.

Yours,
Joel

At 11:21 PM 9/22/2006, Jia Fenggen wrote:
>I agree that Port LFB should only include 
>functionality that is closely coupled to the 
>media.I take functionality coupled to the media 
>as assembling cells to packets and deassembling 
>packets to cells,media data form coversion to FE 
>processing data form,that is to say the port LFB 
>FE side input and output is frame,the media side 
>output and input is cell or some form else,and I 
>temp to add to LFB as L2 decap and L2 encap to 
>capture the frame processing,like classify 
>frames into ipv4 and ipv6,strip off L2 header 
>and do L2 filtering,what do you suppose?
>Yours,Fenggen
>>From: "Joel M. Halpern" <[email protected]>
>>Reply-To: "Joel M. Halpern" <[email protected]>
>>To: [email protected]
>>Subject: Re: question on draft-lfblb-draft.txt?
>>Date: Fri, 22 Sep 2006 09:24:28 -0400
>>
>>I have removed the diagam below.  It ended up 
>>so wide that I could not get a good view of it.
>>
>>I am pretty sure that you are asking what the 
>>relationship is between the port LFB and 
>>various forms of processing such as layer 2 
>>validation, layer 3 validation, forwarding lookup, etc.
>>
>>The general guideline is that processing that 
>>is logically distinct should be in different 
>>LFBs.  Thus L3 validation L3 Next Hop 
>>selection, and Next hop application are ll 
>>proposed in the library to be separate LFBs.
>>The Port LFB should only include functionality 
>>that is closely coupled to the media.  So I 
>>have suggested that media decapsulation (or 
>>encapsulation) goes in the Port (or Generic Connectivity) LFB.
>>Media errors are also counted in that LFB.
>>
>>However, that decomposition is just a 
>>suggestion.  The working group has not adopted 
>>the library draft.  Other folks haven't started 
>>writing class definitions for the draft.  If 
>>there is a different decomposition that helps 
>>us represent the range of implementations of 
>>routers and other packet processing devices, I am open to hearing it.
>>
>>Yours,
>>Joel M. Halpern
>>
>>At 01:11 AM 9/22/2006, Jia Fenggen wrote:
>>>Still another question about port LFB,in 
>>>convention router,packet processing on 
>>>interface always be divided into to 
>>>stages:ingress and egress processing,ingress 
>>>handles things like L2 decap,Forwarding table 
>>>lookup and then send the packets to fabric 
>>>which will deliver it to egress side for 
>>>queuing and scheduling for sending out to 
>>>media.This two stage may reside in an 
>>>interface processing card in modern routers.My 
>>>question is the Port LFB reside and fuctions in such model.As model pictures:
>>...
>>>what's relationship between Ingress\Egress in 
>>>the above draw and the Port LFB?Should we give 
>>>an example LFB topology which use the Port 
>>>LFB,in part to satify the ForCES Requriment 
>>>and in another aspect make the reader known more of the model? Yours,Fenggen
>
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