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RE: Optical impairments in draft-ietf-mpls-generalized-signaling- 04
Hi John,
please see my comments in line.
Best regards.
Diego.
----------------------------------------------------------------
Diego Caviglia
Photonic Networks Design and Modeling
E-mail: diego.caviglia@marconi.com
Tel: +39 (0) 10 6003 808
Via A. Negrone 1A 16153 Genoa (Italy)
http://www.marconi.com
John Drake <jdrake@calient.net> on 26/06/2001 23.57.48
To: "'Heiles Juergen'" <Juergen.Heiles@icn.siemens.de>,
"'Yangguang Xu'" <xuyg@lucent.com>, Diego
Caviglia/MAIN/MC1@MCMAIN
cc: Ayan Banerjee <abanerjee@calient.net>,
ccamp@ops.ietf.org, Giovanni
Fiaschi/MAIN/MC1@MCMAIN
Subject: RE: Optical impairments in
draft-ietf-mpls-generalized-signaling- 04
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.
[dc] John could you please clarify why distribute wavelength availability
that could be even encoded in only 160 bits per fiber (1 lambda available
0 lambda unavailable) doesn't scale while distribute other link related
information such as those described in OSPF TE extension scales?
Yes I agree that race condition is always a problem when resource information is
distributed in a non-instantaneous way.
But this is also valid for Unreserved Bandwidth sub-TLV in OSPF TE extension.
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.
[dc] I know that at present OXC are bordered with transponder
but in this case what is the purpose of Label set object?
I mean in this scenario (DWDM line terminal always perform OEO conversion)
from a routing perspective we don't have to worry at all about optical
impairments
we have just to leave them to DWDM network planning engineers.
-----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