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RE: [PWE3] PWE3 question

To: "'Sasha Vainshtein'" <Sasha@AXERRA.com>, "'Andrew G. Malis'" <Andy.Malis@VivaceNetworks.com>
Subject: RE: [PWE3] PWE3 question
From: Shahram Davari <Shahram_Davari@pmc-sierra.com>
Date: Thu, 9 May 2002 13:59:02 -0700
Cc: "'pwe3@ietf.org'" <pwe3@ietf.org>, "Danny McPherson (E-mail)" <danny@tcb.net>
List-Id: Pseudo Wires Edge to Edge <pwe3.ietf.org>
Sender: pwe3-admin@ietf.org
Sasha,

> -----Original Message-----
> From: Sasha Vainshtein [mailto:Sasha@AXERRA.com]
> Sent: Thursday, May 09, 2002 5:45 PM
> To: Shahram Davari; Sasha Vainshtein; 'Andrew G. Malis'
> Cc: 'pwe3@ietf.org'; Danny McPherson (E-mail)
> Subject: RE: [PWE3] PWE3 question
> 
> 
> Shahram,
> I agree that it is possible to force the routers in
> the PSN to allocate a label per a VC FEC without
> understanding it.
> However I donot agree that this does not mean
> exerting control over the network - and this should
> not be done in PWE3.

In what respect do you see this exerting control over the
PSN network? In contrast I don't see any.

> Once more, I donot say that what you propose cannot be 
> done - I just claim that this is beyound the scope defined
> by the PWE3 chapter.

Since the PSN interior nodes need not know anything about the
PW, I think this actually falls within PWE3 charter.

-Shahram

> 
> --------------------------------------------------------------
> --------------
> --------
> With best regards,
>                           Sasha Vainshtein
> email:   sasha@axerra.com <mailto:sasha@axerra.com> 
> phone:  +972-3-7659993 (office)
>             +972-8-9254948 (home)
>             +972-58-674833 (cellular)
> 
> 
> > -----Original Message-----
> > From: Shahram Davari [mailto:Shahram_Davari@pmc-sierra.com]
> > Sent: Thursday, May 09, 2002 5:31 PM
> > To: 'Sasha Vainshtein'; 'Andrew G. Malis'
> > Cc: 'pwe3@ietf.org'; Danny McPherson (E-mail)
> > Subject: RE: [PWE3] PWE3 question
> > 
> > 
> > Sasha,
> > 
> > LSP ID is used to make sure that CR-LDP never advertises
> > the same label to two different requests.
> > 
> > And M-bit=0 (merge bit) could be used in RSVP-TE to make sure
> > that no merging occurs.
> > 
> > -Shahram
> > 
> > > -----Original Message-----
> > > From: Sasha Vainshtein [mailto:Sasha@AXERRA.com]
> > > Sent: Thursday, May 09, 2002 12:06 PM
> > > To: Shahram Davari; Sasha Vainshtein; 'Andrew G. Malis'
> > > Cc: 'pwe3@ietf.org'; Danny McPherson (E-mail)
> > > Subject: RE: [PWE3] PWE3 question
> > > 
> > > 
> > > Shahram,
> > > I am confused.
> > > If the intermediate routers recognize only ERO 
> > > what would prevent them from advertizing upstream the same 
> > label for 
> > > all the PWs along the same path? 
> > > IMHO both PEs needs a unique label per PW (in one direction);
> > > I do not understand how this can be achieved if the intermediate
> > > routers do not recognize different VC FECs.
> > > 
> > > With best regards,
> > >                                    Sasha Vainshtein
> > > email:     sasha@axerra.com <mailto:sasha@axerra.com> 
> > > tel:       +972-3-7659993 (office)
> > >            +972-8-9254948 (res.)
> > >            +972-58-674833 (cell.)
> > >  
> > > 
> > > 
> > > > -----Original Message-----
> > > > From: Shahram Davari [mailto:Shahram_Davari@pmc-sierra.com]
> > > > Sent: Thursday, May 09, 2002 2:57 PM
> > > > To: 'Sasha Vainshtein'; 'Andrew G. Malis'
> > > > Cc: 'pwe3@ietf.org'; Danny McPherson (E-mail)
> > > > Subject: RE: [PWE3] PWE3 question
> > > > 
> > > > 
> > > > Sasha,
> > > > 
> > > > ER-LSPs work by DoD label assignment. And the ERO 
> > > identifies the path.
> > > > VC FEC is not needed to be processed in the intermediate 
> > > LSRs at all.
> > > > 
> > > > -Shahram
> > > > 
> > > > > -----Original Message-----
> > > > > From: Sasha Vainshtein [mailto:Sasha@AXERRA.com]
> > > > > Sent: Thursday, May 09, 2002 2:58 AM
> > > > > To: Shahram Davari; 'Andrew G. Malis'
> > > > > Cc: 'pwe3@ietf.org'; Danny McPherson (E-mail)
> > > > > Subject: RE: [PWE3] PWE3 question
> > > > > 
> > > > > 
> > > > > Shahram,
> > > > > 
> > > > > IMHO, if you use only one label for a PW, it is this 
> label that
> > > > > is switched through the path from ingress to egress. 
> > > > > Aand if the routesr do not recognize the VC FEC, how should
> > > > > they assign and switch labels associated with this FEC?
> > > > > 
> > > > > With best regards,
> > > > >                                    Sasha Vainshtein
> > > > > email:     sasha@axerra.com <mailto:sasha@axerra.com> 
> > > > > tel:       +972-3-7659993 (office)
> > > > >            +972-8-9254948 (res.)
> > > > >            +972-58-674833 (cell.)
> > > > >  
> > > > > 
> > > > > 
> > > > > > -----Original Message-----
> > > > > > From: Shahram Davari [mailto:Shahram_Davari@pmc-sierra.com]
> > > > > > Sent: Wednesday, May 08, 2002 9:05 PM
> > > > > > To: 'Sasha Vainshtein'; 'Andrew G. Malis'
> > > > > > Cc: 'pwe3@ietf.org'; Danny McPherson (E-mail)
> > > > > > Subject: RE: [PWE3] PWE3 question
> > > > > > 
> > > > > > 
> > > > > > Sasha,
> > > > > > 
> > > > > > I don't think in this case all the routers in the PSN
> > > > > > need to recognize the VC FEC.  You could set the 
> U/F bits to 1
> > > > > > in VC FEC, therefore no need for the interior routers to
> > > > > > recognize the VC FEC.
> > > > > > 
> > > > > > 
> > > > > > -Shahram
> > > > > > 
> > > > > > 
> > > > > > 
> > > > > > > -----Original Message-----
> > > > > > > From: Sasha Vainshtein [mailto:Sasha@AXERRA.com]
> > > > > > > Sent: Wednesday, May 08, 2002 1:59 PM
> > > > > > > To: 'Andrew G. Malis'; Shahram Davari
> > > > > > > Cc: 'pwe3@ietf.org'; Danny McPherson (E-mail)
> > > > > > > Subject: RE: [PWE3] PWE3 question
> > > > > > > 
> > > > > > > 
> > > > > > > Andy and Shahram,
> > > > > > > 
> > > > > > > IMHO using only one label would, regardless
> > > > > > > of the other issues, violate one of the requirements
> > > > > > >  of the PWE3 Charter:
> > > > > > > 
> > > > > > > <quote>
> > > > > > > PWE3 will not exert controls on the underlying PSN,
> > > > > > > but only function at the endpoints of the pseudo wire, 
> > > > > > > though the endpoints may be configured to set diffserv 
> > > > > > > codepoints in the tunneling datagrams. 
> > > > > > > <end quote>
> > > > > > > 
> > > > > > > Building an explicit TE tunnel for a single PW 
> means to me 
> > > > > > > exerting a control over the PSN (e.g., all the routers 
> > > > in the PSN
> > > > > > > should recognize VC FECs etc.).
> > > > > > > 
> > > > > > > In other words, it probably can be done, but it would 
> > > > not be PWE3.
> > > > > > > 
> > > > > > > With best regards,
> > > > > > >                                    Sasha Vainshtein
> > > > > > > email:     sasha@axerra.com <mailto:sasha@axerra.com> 
> > > > > > > tel:       +972-3-7659993 (office)
> > > > > > >            +972-8-9254948 (res.)
> > > > > > >            +972-58-674833 (cell.)
> > > > > > >  
> > > > > > > 
> > > > > > > 
> > > > > > > > -----Original Message-----
> > > > > > > > From: Andrew G. Malis 
> > [mailto:Andy.Malis@VivaceNetworks.com]
> > > > > > > > Sent: Wednesday, May 08, 2002 5:51 PM
> > > > > > > > To: Shahram Davari
> > > > > > > > Cc: 'Andrew G. Malis'; 'pwe3@ietf.org'
> > > > > > > > Subject: RE: [PWE3] PWE3 question
> > > > > > > > 
> > > > > > > > 
> > > > > > > > Shahram,
> > > > > > > > 
> > > > > > > > Yeah, you would have to treat each VC as a separate TE 
> > > > > > > tunnel and use 
> > > > > > > > either RSVP-TE or CR-LDP for signaling 
> (suitably extended 
> > > > > > > > along Martini 
> > > > > > > > lines for VC type and ID).
> > > > > > > > 
> > > > > > > > Cheers,
> > > > > > > > Andy
> > > > > > > > 
> > > > > > > > -------
> > > > > > > > 
> > > > > > > > At 5/8/2002 08:33 AM -0700, Shahram Davari wrote:
> > > > > > > > >Andy,
> > > > > > > > >
> > > > > > > > >Sure I understand the scaling issue. But ignoring the 
> > > > > > scalability,
> > > > > > > > >I want to know if it can be done and if so how?
> > > > > > > > >
> > > > > > > > >It seems that you may not be able to use LDP any more, 
> > > > > > > because VC FEC
> > > > > > > > >is meaningless to the interior LSRs. But it 
> > seems that you 
> > > > > > > could use
> > > > > > > > >ER-LSPs and therefore do TE. Right?
> > > > > > > > >
> > > > > > > > >Yours,
> > > > > > > > >-Shahram
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > > -----Original Message-----
> > > > > > > > > > From: Andrew G. Malis 
> > > [mailto:Andy.Malis@vivacenetworks.com]
> > > > > > > > > Sent: Tuesday, May 07, 2002 6:12 PM
> > > > > > > > > To: Shahram Davari
> > > > > > > > > Cc: 'pwe3@ietf.org'
> > > > > > > > > Subject: Re: [PWE3] PWE3 question
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Shahram,
> > > > > > > > >
> > > > > > > > > Well, it wouldn't scale very well since every 
> > switch along
> > > > > > > > > the path is
> > > > > > > > > involved in the signaling for each VC, and you can't 
> > > > > do traffic
> > > > > > > > > engineering, so I would say that's pretty much a 
> > > > non-starter.
> > > > > > > > >
> > > > > > > > > Cheers,
> > > > > > > > > Andy
> > > > > > > > >
> > > > > > > > > At 5/7/2002 12:02 PM -0700, Shahram Davari wrote:
> > > > > > > > > >Hi,
> > > > > > > > > >
> > > > > > > > > >Can we implement PWE3 with only one label 
> (i.e., only 
> > > > > > VC label)?
> > > > > > > > > >
> > > > > > > > > >-Shahram
> > > > > > > > > >
> > > > > > > > > >_______________________________________________
> > > > > > > > > >pwe3 mailing list
> > > > > > > > > >pwe3@ietf.org
> > > > > > > > > >https://www1.ietf.org/mailman/listinfo/pwe3
> > > > > > > > >
> > > > > > > 
> > > > > > > 
> > > > > > > _______________________________________________
> > > > > > > pwe3 mailing list
> > > > > > > pwe3@ietf.org
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> > > > > > > 
> > > > > > 
> > > > > 
> > > > 
> > > 
> > 
> 

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