Hi Diego and all, looking at the old MS-SPRing drafts I'm picking up
the following: (a) MS-SPRing nodes (switches) are not required to provide Time slot interchange (TSI). A property of the switches.(generalizes WSON) (b) Time slot continuity is required for correct operation of the restoration protocol. A property of the LSP. (generalizes WSON) (c) A need to disseminate ring map information (RingID, Ring Node #) --> More of a generalization of existing GMPLS info on protection? what I didn't see but wondered about is: (d) Time slot availability on ring links. Wouldn't you need this to perform the time slot continuity constrained path computation. (generalizing RWA concept and WSON available wavelengths). (e) In my past we dealt with trans-oceanic applications and it seemed like some of these constraints were loosened a bit because of the longer time period and differing switching points. Comments? Other items? Other applications? Best Regards Greg Diego Caviglia wrote: Hi all, I think that this is an interesting topic to move on, may be this time we can solve the issue of MS-SPRing interworking with GMPLS control plane that we were able to solve some times ago. May be we can resume the ID about the MS-SPRing we did some time ago and try to elaborate a generalization. BR Diego __________________________________________ Diego Caviglia Strategic Product Manager Broadband Networks, PL Broadband Optical Network Ericsson Telecomunicazioni S.p.A. (TEI) Via A. Negrone 1/A Office: +39 010 600 3736 16153, Genova, Italy Fax: +39 010 600 3577 Block E Level 4 Mobile: +39 335 7181762 www.ericsson.com diego.caviglia@ericsson.com This communication is confidential and intended solely for the addressee(s). Any unauthorized review, use, disclosure or distribution is prohibited. If you believe this message has been sent to you in error, please notify the sender by replying to this transmission and delete the message without disclosing it. Thank you. ________________________________-----Original Message----- From: owner-ccamp@ops.ietf.org [mailto:owner-ccamp@ops.ietf.org] On Behalf Of Greg Bernstein Sent: mercoledì 15 aprile 2009 19.02 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. Insome 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] OnBehalf Of Greg BernsteinSent: 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 veryapplicationspecific to optical switching systems. From section 3.3 Link Information: Switched and Fixed Port Wavelength (label) Restrictions: Generallyuseful: Idon't think so but open to examples. These constraints must be shared intheWSON case for two reasons: (a) the wavelength continuity constraintrequiresglobal label assignment, (b) WSON devices present many different typesofwavelength 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?Otherexamples? 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. Tooapplicationspecific. Comments appreciated Greg-- =================================================== Dr Greg Bernstein, Grotto Networking (510) 573-2237 -- =================================================== Dr Greg Bernstein, Grotto Networking (510) 573-2237 |