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RE: Optical impairments in draft-ietf-mpls-generalized-signaling-04
I'll defer to Peter Ashwood-Smith or Lou Berger, as they were the ones who
designed label sets
-----Original Message-----
From: Yangguang Xu [mailto:xuyg@lucent.com]
Sent: Wednesday, June 27, 2001 8:06 AM
To: John Drake
Cc: ccamp@ops.ietf.org
Subject: Re: Optical impairments in
draft-ietf-mpls-generalized-signaling-04
John,
Can you (or anybody else) give me an example that there are more than one
labels
in the label set for the inclusive case?
Here is a simple picture: A,B,C and D are OXCs
+---+ +---+ +---+ +---+
-----| A |-----| B |----| C |---| D |
| |-----| |----| |---| |
| |-----| |----| |---| |-----
+---+ +---+ +---+ +---+
In your example, please specify your assumption about each OXC, that is
whether
or not it support wavelength conversion.
Thanks a lot,
Yangguang
John Drake wrote:
>
> Announcing wavelength availability information in routing doesn't work
> because of the flooding traffic it would generate, plus there are still
race
> conditions that would have to be handled by signalling anyway. Label set
> was intended to support wavelength continuity issues.
>
> Also, in the short term, we're dealing with transponder based interfaces
to
> the DWDM systems so this is a non-issue. In the longer term, this is just
> another issue like PMD and OSNR that will need to be dealt with.
>
> -----Original Message-----
> From: Heiles Juergen [mailto:Juergen.Heiles@icn.siemens.de]
> Sent: Tuesday, June 26, 2001 7:43 AM
> To: 'Yangguang Xu'; Diego Caviglia
> Cc: Ayan Banerjee; ccamp@ops.ietf.org; Giovanni Fiaschi
> Subject: RE: Optical impairments in
> draft-ietf-mpls-generalized-signaling- 04
>
> Yangguang,
>
> wavelength conversion is in my view an issue for path selection as you
> cannot select a certain path if the wavelength doesn't fit and you have no
> wavelength conversion.
>
> Regards
>
> Juergen
>
> > -----Original Message-----
> > From: Yangguang Xu [SMTP:xuyg@lucent.com]
> > Sent: Tuesday, June 26, 2001 3:13 PM
> > To: Diego Caviglia
> > Cc: Ayan Banerjee; ccamp@ops.ietf.org; Giovanni Fiaschi
> > Subject: Re: Optical impairments in
> draft-ietf-mpls-generalized-signaling-04
> >
> >
> > Diego,
> >
> > As indicated by the document that Ayan pointed to you, there are many
> constrains
> > for the optical networking. These constrains can be considered at
network
> > planning time, path selection time (routing using OSPF-TE/ISIS-TE) or
> connection
> > setup time(GMPLS signaling). When a constrain is considered is an
> engineering
> > issue. We just have to figure out when and where is the best and
cheapest
> to
> > consider a constrain. To wavelength conversion, GMPLS signaling is a
good
> place
> > to handle.
> >
> > Thanks,
> >
> > Yangguang
> >
> > Diego Caviglia wrote:
> > >
> > > Ayan,
> > >
> > > Thanks for your answer but I don't understand why lambda
> conversion is
> > > a signalling problem and thus is covered in generalized signalling
> draft while
> > > others optical impairments are routing problem and are covered in
a
> separate
> > > document.
> > >
> > > Moreover even if the document you quoted is a well written and very
> useful one
> > > it is an informative contribution that simply points out the
> physically
> > > impairments of an all optical network. It doesn't propose any
> extension to
> > > OSPF/IS-IS in order to support optical routing.
> > >
> > > Given that in an All Optical Network we have to cope with
> lots of new
> > > information, as you stated in your document, are we sure that
OSPF,
> in this
> > > environment, scales?
> > >
> > > I mean if it doesn't scale for wavelength availability information
> distribution
> > > why it has to scales for other optical impairment distribution?
> > >
> > > ----------------------------------------------------------------
> > > Diego Caviglia
> > > Photonic Networks Design and Modelling
> > > E-mail: diego.caviglia@marconi.com
> > > Tel: +39 (0) 10 6003 808
> > > Via A. Negrone 1A 16153 Genoa (Italy)
> > > http://www.marconi.com
> > >
> > > Ayan Banerjee <abanerjee@calient.net> on 25/06/2001 22.26.02
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > To: Diego Caviglia/MAIN/MC1@MCMAIN,
> > > petera@nortelnetworks.con, ccamp@ops.ietf.org
> > >
> > > cc: Giovanni Fiaschi/MAIN/MC1@MCMAIN
> > >
> > >
> > >
> > > Subject: RE: Optical impairments in
> > > draft-ietf-mpls-generalized-signaling- 04
> > >
> > >
> > >
>
----------------------------------------------------------------------------
> ----
> > >
> > > Diego,
> > >
> > > Please see draft-ietf-ipo-impairments-00.txt for optical constraints.
> > >
> > > Thanks,
> > > Ayan
> > >
> > > -----Original Message-----
> > > From: Diego Caviglia [mailto:Diego.Caviglia@marconi.com]
> > > Sent: Monday, June 25, 2001 6:19 AM
> > > To: petera@nortelnetworks.con; ccamp@ops.ietf.org
> > > Cc: Giovanni Fiaschi
> > > Subject: Optical impairments in
draft-ietf-mpls-generalized-signaling-04
> > >
> > > Peter ,all,
> > >
> > > a comment about
draft-ietf-mpls-generalized-signaling-04.
> In
> > > the
> > > draft there is the label set object that is very useful in All
optical
> > > networks
> > > with CI-incapable nodes but lambda conversion is only one of
the
> > > problems
> > > related to path establishment in such networks. I mean what
about
> OSNR
> > > and
> > > non-linear impairments? What about gain variation and power
> equalization?
> > > Where
> > > are covered these topic?
> > >
> > > If I can find a path feasible from the lambda continuity point
of
> view
> > > who
> > > assure me that I have the needed Q at the end of the all optical path?
> > >
> > > Best regards.
> > >
> > > ----------------------------------------------------------------
> > > Diego Caviglia>
> > > Photonic Networks Design and Modelling
> > > E-mail: diego.caviglia@marconi.com
> > > Tel: +39 (0) 10 6003 808
> > > Via A. Negrone 1A 16153 Genoa (Italy)
> > > http://www.marconi.com