[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: Generalizing WSON information...
Its also this older SDH equipment that had limitations with respect to the "vector" of a connection -- that is, connections could only go from drop to line or line to line, but couldn't go drop to drop. Some other older devices also had limitations on which ports could be paired for the purposes of protection.
These limitations could be handled as a part of the "switch connectivity matrix".
Jonathan Sadler
-----Original Message-----
From: owner-ccamp@ops.ietf.org [mailto:owner-ccamp@ops.ietf.org] On Behalf Of Greg Bernstein
Sent: Wednesday, April 15, 2009 12:02 PM
To: julien.meuric@orange-ftgroup.com
Cc: ccamp@ops.ietf.org
Subject: Re: Generalizing WSON information...
Hi Julien, interesting point. It did seem like older SDH equipment did
have a "time-slot continuity constraint", but I never directly dealt
with those systems. There was some work a while ago on MS-SPRing (Diego?).
Maybe we need to think up a level, as you said in the usual GMPLS, MPLS
cases full label swapping is a typical capability. Should we be explicit
in the WSON case (maybe with the connectivity matrix) in indicating that
this may or may not be the case? Right now we are being implicit about
this lack of wavelength (label) conversion capability.
The notion of the shared wavelength converter pools and the accompanying
details seem very WSON specific. But the fact that a switch or mux can't
perform label exchange seems a fairly general notion that we could group
with other generalizable information...
Best Regards
Greg
julien.meuric@orange-ftgroup.com wrote:
> Hi Greg.
>
> Just a small comment on Wavelength Converter Pool in section 3.2. In some other GMPLS contexts, this may be modelled as a label swapping capability, which is a common enough to be considered as "Generalizable" (it's even a typical case that becomes an exception due to our label continuity constraint). However, as for several other parameters, I don't think there is an actual need for it (this is already the default); but maybe we could imagine some MS-SPRing operations in SONET/SDH.
>
> Regards,
>
> Julien
>
> -----Original Message-----
> From: owner-ccamp@ops.ietf.org [mailto:owner-ccamp@ops.ietf.org] On Behalf Of Greg Bernstein
> Sent: Tuesday, April 14, 2009 6:32 PM
> To: ccamp
> Subject: Generalizing WSON information...
>
> Hello fellow CCAMPers, at the 74th IETF meeting in San Francisco the
> question
> came up as to what if any of the WSON path computation information model
> would
> be useful in other technologies. Below is a first attempt at such an
> assesment
> based on the current version of draft-ietf-ccamp-rwa-info-02.txt.
> Existing GMPLS
> standard information is not included.
>
> From section 3.2 Node Information:
>
> Switched Connectivity Matrix: Generalizable:Yes. This can be used to
> model any
> type of asymetrical switch in any technology. Caveat: Besides optical is
> there
> any current products that can make use of this?
>
> Fixed Connectivity Matrix: Generalizable: Yes. This can be used to model
> fixed
> connectivity between ports. Caveat: Is there any need outside optical?
>
> Wavelength Converter Pool: Generally useful: No. This is very application
> specific to optical switching systems.
>
> From section 3.3 Link Information:
>
> Switched and Fixed Port Wavelength (label) Restrictions: Generally useful: I
> don't think so but open to examples. These constraints must be shared in the
> WSON case for two reasons: (a) the wavelength continuity constraint requires
> global label assignment, (b) WSON devices present many different types of
> wavelength constraints. Note that without requirement (a) then (b)
> doesn't need
> to be shared since local label (wavelength) assignment would suffice.
>
> From section 3.4 Dynamic Link information
>
> Available Wavelengths (labels): Generally useful? We need detailed
> wavelength
> availability information due to the wavelength continuity constraint.
> Way back
> in the old days many of us implemented bit maps to track SONET/SDH time
> slots
> but this never made it into the standards. Any interest in that now? Other
> examples?
>
> Shared Backup Wavelengths (labels): Similar to the above but used in
> efficient
> shared mesh backup path computation.
>
> From section 3.5 Dynamic Node Information
>
> Wavelength Converter Pool Status: Not generally applicable. Too application
> specific.
>
> Comments appreciated
>
> Greg
>
>
--
===================================================
Dr Greg Bernstein, Grotto Networking (510) 573-2237
============================================================
The information contained in this message may be privileged
and confidential and protected from disclosure. If the reader
of this message is not the intended recipient, or an employee
or agent responsible for delivering this message to the
intended recipient, you are hereby notified that any reproduction,
dissemination or distribution of this communication is strictly
prohibited. If you have received this communication in error,
please notify us immediately by replying to the message and
deleting it from your computer. Thank you. Tellabs
============================================================