The MPLS WG Archive

[Shahram Davari <Shahram_Davari@pmc-sierra.com>]

Hi Grenville,

Accordingly, we could remove the (P) from the non-PHP figures too.

Regards,
-Shahram

>-----Original Message-----
>From: Shahram Davari [mailto:Shahram_Davari@pmc-sierra.com]
>Sent: Friday, June 30, 2000 10:17 AM
>To: 'Grenville Armitage'; Francois Le Faucheur
>Cc: mpls@UU.NET
>Subject: RE: Figures in 2.6.3&2.6.4 Re: Last Call feedback on
>MPLS-Diff-Se rv
>
>
>Hi Grenville,
>
>Good catch. How about removing the parentheses surrounding 
>(E), (I), (P) and
>add to the bottom of the figures the definition of E, I and P. In
>other words how about this:
>
>         ========== LSP ==========================>
>                 +--Swap-(M)-...-Swap-(M)--+
>                /        (outer header)     \
>              (M)                           (M)
>              /                               \
>   >--(M)--Push...............(x)............Pop-(M)--E--(M)->
>             I            (inner header)      P
>
>(M) represents the Meaningful Diff-Serv information encoded in the
>   corresponding header.   
>(x) represents non-meaningful Diff-Serv information.
>
> I  represents the tunnel's Ingress node
> E  represents the tunnel's Egress node
> P  represents the tunnel's Penultimate node.
>
>
>Cheers,
>-Shahram 
>
>>-----Original Message-----
>>From: Grenville Armitage [mailto:gja@dnrc.bell-labs.com]
>>Sent: Thursday, June 29, 2000 8:00 PM
>>To: Francois Le Faucheur
>>Cc: mpls@UU.NET
>>Subject: Figures in 2.6.3&2.6.4 Re: Last Call feedback on 
>>MPLS-Diff-Serv
>>
>>
>>Francois,
>>
>>Use of "(P)" in second figures of 2.6.3 and 2.6.4:
>>
>>Francois Le Faucheur wrote:
>>	[..]
>>> >#6 Section 2.6.3, 2nd Figure
>>> >
>>> >   There's a "(P)" floating to the right of "(outer header)"
>>> >   that perhaps ought not be there?  (Same for 2nd figure in
>>> >   section 2.6.4)
>>> 
>>> (P) indicates the penultimate LSR in all diagrams. It appears at the
>>> right location even in the 2nd figures (ie without PHP). It insists
>>> on the fact that in those cases (P) does a swap (and not a pop) so
>>> that the "outer header" is there between (P) and (E) to carry some
>>> Diff-Serv info .
>>
>>Okay, I now understand the intent. But now I'm not sure the ASCII art
>>is clear. In the non-PHP examples the "(P)" _appears_ to sit two hops
>>prior to the "(E)" LSR, which is confusing. (Alternatively, it isn't
>>clear from the ASCII art how to distinguish LSRs and links and
>>therefore derive the message you intend about where the egress
>>hops and penultimate hops exist. I can't figure out if the "(M)"
>>represent LSRs or links using 'meaningful diffserv info' - my
>>initial read took them as LSRs.) Perhaps the ASCII art could
>>be clarified (or we could just assume readers know that non-PHP
>>means "label swap all the way"?)
>>
>>cheers,
>>gja
>>_______________________________________________________________
>>_________
>>Grenville Armitage                    
>>http://members.home.net/garmitage/
>>Bell Labs Research Silicon Valley
>>
>