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RE: comments on draft-shiba-ccamp-gmpls-lambda-labels-00.txt
Absolutely right.....'space' is always a consideration for 1 dimension
of the labelling of resource partitions in the co-cs mode....once space
has been labelled then we need to know whether we are dealing with a
'freq' or 'time' label next (there is actually a 3rd possibility wrt
'amplitutde' labelling....code division muxing). And to be of practical
use, these has to be an implicit assumed binding of known bit rate to
this.
regards, neil
> -----Original Message-----
> From: owner-ccamp@ops.ietf.org
> [mailto:owner-ccamp@ops.ietf.org] On Behalf Of Payam Torab
> Sent: 31 October 2005 16:12
> To: 'Drake, John E'; 'Shiba, Sidney'; dpapadimitriou@psg.com
> Cc: 'Adrian Farrel'; richard.rabbat@us.fujitsu.com; ccamp@ops.ietf.org
> Subject: RE: comments on draft-shiba-ccamp-gmpls-lambda-labels-00.txt
>
>
> John-
>
> Obviously the benefits or harms of giving a global meaning to
> a lambda label requires study, but your particular example is
> not a good one: If one really wants to have a preference for
> a specific wavelength channel among multiple parallel
> channels of the same wavelength, bundling should not be
> exercised in the first place.
>
> Thanks,
> Payam
>
> -----Original Message-----
> From: owner-ccamp@ops.ietf.org [mailto:owner-ccamp@ops.ietf.org]On
> Behalf Of Drake, John E
> Sent: Monday, October 31, 2005 10:36 AM
> To: Shiba, Sidney; dpapadimitriou@psg.com
> Cc: Adrian Farrel; richard.rabbat@us.fujitsu.com; ccamp@ops.ietf.org
> Subject: RE: comments on draft-shiba-ccamp-gmpls-lambda-labels-00.txt
>
>
> Sidney,
>
> But there's nothing in your picture that requires an absolute
> end-end global wavelength. The existing GMPLS solution with
> relative wavelengths of local significance should work just
> fine. As I said in my previous note, your method precludes
> combining two or more parallel WDM links into a single TE link.
>
> Thanks,
>
> John
>
> > -----Original Message-----
> > From: Shiba, Sidney [mailto:sidney.shiba@us.fujitsu.com]
> > Sent: Monday, October 31, 2005 7:25 AM
> > To: Drake, John E; dpapadimitriou@psg.com
> > Cc: Adrian Farrel; richard.rabbat@us.fujitsu.com; ccamp@ops.ietf.org
> > Subject: RE: comments on
> draft-shiba-ccamp-gmpls-lambda-labels-00.txt
> >
> > Hi John,
> >
> > Optical switches based on Wavelength Selective Switch (WSS)
> technology
> > requires the wavelength information for switching. This
> technology is
> NOT
> > wavelength agnostic.
> >
> > | |
> > | wdm | wdm
> > |2 |2
> > --------- ---------
> > wdm 1| optical |3 wdm 1| optical |3 wdm
> > --------| switch |------------| switch |---------
> > | (WSS) | | (WSS) |
> > --------- ---------
> > |4 |4
> > | wdm | wdm
> > | |
> >
> > Note that the figure above shows an example of two optical switches
> > interconnect by a single WDM fiber. In this example, each optical
> > switch can be
> connect
> > to 4
> > other optical switches.
> >
> > As you can see, the optical ports information do not provide enough
> > information for wavelength switching.
> >
> > Hope that clarifies the application requirement.
> >
> > Thanks,
> >
> > Sidney
> >
> > > -----Original Message-----
> > > From: Drake, John E [mailto:John.E.Drake2@boeing.com]
> > > Sent: Friday, October 28, 2005 5:33 PM
> > > To: dpapadimitriou@psg.com; Shiba, Sidney
> > > Cc: Adrian Farrel; richard.rabbat@us.fujitsu.com;
> ccamp@ops.ietf.org
> > > Subject: RE: comments on
> draft-shiba-ccamp-gmpls-lambda-labels-00.txt
> > >
> > >
> > > Hi,
> > >
> > > Below is the text of an e-mail is sent to the
> Ethernet/GMPLS mailing
> > > list.
> > >
> > > Upon reflection I am not sure using a real wavelength value makes
> much
> > > sense. Between a pair of adjacent nodes, there may be multiple
> > > pairs of switch ports in the same TE link that support a given
> > > frequency. If
> a
> > > real wavelength value is used, how do the two nodes agree
> on which
> > > pair of switch ports to use?
> > >
> > > Furthermore, the amount of configuration is the same - you still
> > > need to configure the wavelength of each switch port.
> > >
> > > Thanks,
> > >
> > > John
> ==============================================================
> > > ==========
> > > ====
> > > Adrian,
> > >
> > > In the transparent photonic lambda switch case, the
> labels also have
> > > only local significance. When an LSP is established, the input
> ports,
> > > as identified with local labels, are cross-connected to
> the output
> > > ports, as identified with local labels.
> > >
> > > There is just extra configuration to identify, using
> strictly local
> > > identifiers, the wavelength associated with the all of
> the switch's
> > > ports, and an additional CAC requirement that the
> wavelengths of the
> > > input and output ports are the same.
> > >
> > > Thanks,
> > >
> > > John
> > >
> > >
> > > > -----Original Message-----
> > > > From: dimitri papadimitriou [mailto:dpapadimitriou@psg.com]
> > > > Sent: Thursday, October 27, 2005 10:03 AM
> > > > To: Shiba, Sidney
> > > > Cc: dimitri.papadimitriou@alcatel.be; Adrian Farrel;
> > > > richard.rabbat@us.fujitsu.com; ccamp@ops.ietf.org
> > > > Subject: Re: comments on
> > > draft-shiba-ccamp-gmpls-lambda-labels-00.txt
> > > >
> > > > shiba - see inline for some additional hints:
> > > >
> > > > >>Shiba, Sidney wrote:
> > > > >>
> > > > >>>Adrian, Dimitri,
> > > > >>>
> > > > >>>Thanks for reviewing these I-D.
> > > > >>>
> > > > >>>Wavelength continuity constraint does require the use of
> > > semanticful
> > > > >>>label whether it is spectral or index.
> > > > >>
> > > > >>=> see my reply to adrian on this specific point
> > > > >>
> > > > >>>I agree with Dimitri that the
> > > > >>>wavelength indexing requires document updating each
> time a new
> > > > >>>spectrum is introduced.
> > > > >>
> > > > >>=> indeed and in addition it requires updating the already
> > > > >>signaled path
> > > > >>
> > > > >>>The use of spectral label provides self
> maintainance, i.e., no
> > > > >>>need to update any document and the use of the nominal value
> > > > >>>provides a common semantic ground.
> > > > >>
> > > > >>=> what do you mean by self-maintenance - would you provide a
> > > > >>bit more detail
> > > > >
> > > > > [Sidney]What I've meant here was that it was not necessary to
> > > > > update any document when new wavelengths are
> inventoried. In the
> > > > > case of indexing approach, it would require the
> > > wavelength indexing
> > > > > document to be updated with implementation impacts.
> > > > >
> > > > > In the case, the nominal value is used, there is no need for
> > > > > documentation update.
> > > >
> > > > ok - what you mean here is that you are going to make use of the
> > > already
> > > > defined C-Type 2 - what about the specific encoding of the
> > > value space
> > > ?
> > > >
> > > > >>=> now i have a more specific question before being
> light-up how
> > > > >>do you know the frequency that you can support ?
> > > > >
> > > > > [Sidney] Some new technologies integrate optical switch and
> > > mux/demux
> > > > > capabilities, which allows the equipment to know the
> spectrum it
> > > > supports.
> > > >
> > > > indeed - but the question is what does happen if the
> > > "detected" values
> > > > (during initialization) do not match the nominal values ? you
> don't
> > > > initialize then ?
> > > >
> > > > >>if these differ from the nominal values how are you going to
> deal
> > > with
> > > > these
> > > > >>discrepancies ?
> > > > >
> > > > > [Sidney] These new technologies uses the nominal value as
> > > reference.
> > > We
> > > > can say
> > > > > that a lightpath wavelength is identified by its
> nominal value.
> If
> > > the
> > > > equipment
> > > > > is drifting from this nominal value, it is considered as
> > > a failure.
> > > >
> > > > ok - but if the deviation is such you have overlap - how the
> control
> > > > plane is going to be able to detect such failure ?
> > > >
> > > > >>this said i am not necessarily sure that having to
> > > maintain the data
> > > > plane
> > > > >>specifics as part of the control plane is really helping
> > > > >>operations (is this method not just duplicating complexity ?)
> > > > >
> > > > > [Sidney] The wavelength is WDM specific as much as the SUKLM
> label
> > > > encoding
> > > > > is for SONET. The wavelegth/frequency nominal value is used to
> > > identify
> > > > the
> > > > > facilities to cross-connect.
> > > >
> > > > there is an equivalence but there is also a major
> difference, the
> > > > structure is invariant independently of the state of the
> > > network, with
> > > > spectral value space you may have labels that become unavailable
> due
> > > to
> > > > non-local usage of wavelength in the network
> > > >
> > > > hence, there is also no real coupling to the data plane
> more than
> > > > knowing the type of interface and some generic capabilities
> > > >
> > > > >>>I'm not sure if the draft needs to be updated before the
> > > > >>>face-to-face meeting or after all comments are collected.
> Please
> > > > advise.
> > > > >>
> > > > >>=> suggest to keep discussion on - document update can be
> > > > >>performed at a later stage
> > > >
> > > > thanks,
> > > > - dimitri.
> > > >
> > > > >>>>-----Original Message-----
> > > > >>>>From: owner-ccamp@ops.ietf.org
> > > [mailto:owner-ccamp@ops.ietf.org]On
> > > > >>>>Behalf Of Adrian Farrel
> > > > >>>>Sent: Thursday, October 27, 2005 4:45 AM
> > > > >>>>To: dpapadimitriou@psg.com;
> dimitri.papadimitriou@alcatel.be;
> > > > >>>>ccamp@ops.ietf.org
> > > > >>>>Subject: Re: comments on
> > > > >>
> > > > >>draft-shiba-ccamp-gmpls-lambda-labels-00.txt
> > > > >>
> > > > >>>>
> > > > >>>>Dimitri,
> > > > >>>>
> > > > >>>>Thanks for your work reviewing these recent I-Ds.
> It is really
> > > > >>>>valuable and I'd welcome other people doing similar reviews.
> > > > >>>>
> > > > >>>>
> > > > >>>>
> > > > >>>>>there is a specific point to be clarified in this document:
> > > > >>>>>
> > > > >>>>>semanticless vs semanticful label (even here there is a
> > > distinction
> > > > >>>>>between spectral vs indexes i.e. using the
> wavelength index)
> > > > >>>>>
> > > > >>>>>domain-wide vs link local significant label
> > > > >>>>
> > > > >>>>Without being too picky, I think all labels are semanticful
> > > > >>>>otherwise, we would not know what resource they refered to.
> > > > >>>>
> > > > >>>>So the point reduces to whether the scope of the
> semantics are
> > > > >>>>link-local or wider.
> > > > >>>>
> > > > >>>>
> > > > >>>>
> > > > >>>>>so, the comparison from this perspective with TDM labels is
> > > > >>>>
> > > > >>>>difficult to
> > > > >>>>
> > > > >>>>
> > > > >>>>>parse, the latter is semanticful but link local
> > > > >>>>>
> > > > >>>>>now, i don't specifically see what has changed the
> late 90's,
> > > early
> > > > >>>>>y2k's, to have a change in the wavelength label definition;
> > > > >>>>
> > > > >>>>This is the question I would like to get to the
> bottom of. In
> > > > >>>>other words: do we need this function?
> > > > >>>>
> > > > >>>>It seems to me that the question being asked is this:
> > > > >>>>
> > > > >>>> If I want to compute a path that has some form of
> wavelength
> > > > >>>> constraints, what information do I need access to?
> > > > >>>>
> > > > >>>>Another question might be:
> > > > >>>>
> > > > >>>> If I want to signal a path with wavelength
> constraints what
> > > > >>>> information do I need to include in the signaling message?
> > > > >>>>
> > > > >>>>
> > > > >>>>I'd suggest that when we started on GMPLS, we were
> > > > >>
> > > > >>enthusiastic about
> > > > >>
> > > > >>>>transparent optical networks, but we were not properly
> > > > >>>>focusing wavelength constraints because
> lambda-switching PXCs
> > > > >>>>didn't take off. Therefore we
> > > > >>>>didn't examine the requirements for wavelength
> constraints in
> > > > >>>>routing and
> > > > >>>>signaling. The authors of this I-D are claiming new hardware
> > > > >>>>requirements
> > > > >>>>for the same function.
> > > > >>>>
> > > > >>>>
> > > > >>>>
> > > > >>>>>there are
> > > > >>>>>several solution possible
> > > > >>>>>
> > > > >>>>>- absolute values: the freq. of the wavelength:
> difficult to
> > > adopt
> > > > >>>>>because referenced values are nominal and knowing all
> > > interactions
> > > > >>>>>between wavelengths this knowledge is at the end of little
> > > > >>
> > > > >>practical
> > > > >>
> > > > >>>>>usage; (introduces implicit ordering)
> > > > >>>>>
> > > > >>>>>- indexed values: the # of the wavelength: it does not
> > > > >>
> > > > >>provide for a
> > > > >>
> > > > >>>>>future proof label space for inst. in case new frequencies
> > > > >>>>
> > > > >>>>are inserted
> > > > >>>>
> > > > >>>>
> > > > >>>>>in the grid (introduces explicit ordering)
> > > > >>>>>
> > > > >>>>>- diff. values e.g. freq spacing starting from a reference
> > > > >>>>
> > > > >>>>value: pauses
> > > > >>>>
> > > > >>>>
> > > > >>>>>the question of the reference value and does
> suffer from the
> > > former
> > > > >>>>>issue (introduces implicit ordering)
> > > > >>>>>
> > > > >>>>>- the solution available today - cumbersome in some
> > > control plane
> > > > >>>>>operations (e.g. label set translation) and not easy to
> > > > >>>>
> > > > >>>>troubleshoot but
> > > > >>>>
> > > > >>>>
> > > > >>>>>independent of any physical consideration (spectral), scale
> to
> > > any
> > > > >>>>>number of wavelength per fiber, does not introduce any
> > > > >>
> > > > >>ordering, the
> > > > >>
> > > > >>>>>most flexible (since allowing each system to maintain its
> > > specific
> > > > >>>>>control operations) and the less constraining since
> maintaining
> > > the
> > > > >>>>>control plane operations independent of any data plane
> > > specifics
> > > > >>>>>
> > > > >>>>>
> > > > >>>>
> > > >
> >>>><http://www.ietf.org/internet-drafts/draft-shiba-ccamp-gmp
ls-l
> > > >>>
> > > >>>ambda-labels
> > > >>>-00.txt>
> > > >>>
> > > >>>.
> > > >>>
> > > >>
> > > >
> > > > .
> > > >
> >