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RE: comments on draft-shiba-ccamp-gmpls-lambda-labels-00.txt
John,
When multi-vendor configuration is involved, regenerators (e.g, G.709
OEO conversion) are usually used to interface two systems. In this case,
tunable laser regenerators need to be tuned to the desired wavelength.
Hope that helps to identify the interoperability requirement.
BTW, the draft provides some "requirements" related to Label Set. I'm
curious to know how this is addressed with local significance labels.
Thanks,
Sidney
> -----Original Message-----
> From: Drake, John E [mailto:John.E.Drake2@boeing.com]
> Sent: Monday, October 31, 2005 11:12 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
>
> 'm not sure you are addressing my concern, unless you are telling me
> that an LSP can be instantiated along a path that contains WDM systems
> from *different* vendors. I had been told that, in general, this was
> not the case.
>
> Thanks,
>
> John
>
> > -----Original Message-----
> > From: Shiba, Sidney [mailto:sidney.shiba@us.fujitsu.com]
> > Sent: Monday, October 31, 2005 8:00 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
> >
> > John,
> >
> > Most of vendor support a standardized wavelength grid
> > (e.g., ITU-T DWDM wavelength grid given in nominal value).
> >
> > If a wavelength chosen for a lightpath setup is not available
> > in an optical switch, it rejects the operation for resource
> > not being available.
> >
> > Regards,
> >
> > Sidney
> >
> > > -----Original Message-----
> > > From: Drake, John E [mailto:John.E.Drake2@boeing.com]
> > > Sent: Monday, October 31, 2005 9:51 AM
> > > 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
> > >
> > >
> > > Sidney,
> > >
> > > There's another issue as well. Having absolute end-end global
> > > wavelengths is probably insufficient to ensure that an end-end LSP
> can
> > > be established successfully, as having a common wavelength
> > > does not mean
> > > that equipment from different vendors will interoperate
> > > correctly in the
> > > data-plane.
> > >
> > > Thanks,
> > >
> > > John
> > >
> > > > -----Original Message-----
> > > > From: Drake, John E
> > > > Sent: Monday, October 31, 2005 7:36 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-gmpls-l
> > > > > > > >>>
> > > > > > > >>>ambda-labels
> > > > > > > >>>-00.txt>
> > > > > > > >>>
> > > > > > > >>>.
> > > > > > > >>>
> > > > > > > >>
> > > > > > > >
> > > > > > > > .
> > > > > > > >
> > > > > >
> > >
>