Re: MS-SPring [Was: Moving forward with the CCAMP charter]

["Diego Caviglia" <Diego.Caviglia@marconi.com>]

Dimitri,
         in line.

Regards

Diego



dimitri papadimitriou <dpapadimitriou@psg.com> on 17/08/2005 17.01.23

Please respond to dpapadimitriou@psg.com; Please respond to
       dimitri.papadimitriou@alcatel.be

To:    Diego Caviglia <Diego.Caviglia@marconi.com>
cc:    dimitri.papadimitriou@alcatel.be, "richard.spencer"
       <richard.spencer@bt.com>, adrian <adrian@olddog.co.uk>, ccamp
       <ccamp@ops.ietf.org>

Subject:    Re: MS-SPring [Was: Moving forward with the CCAMP charter]

diego

Diego Caviglia wrote:
> Hi Dimitri,
>             given the high number of MS-SPRing protected transport
network
> already deployed seems reasonable to me, from a Network Operator point of
> view, to use at the same time MS-SPRing protection with GMPLS
restoration.

there are already two questions here 1. is there an operational need to
control such rings using GMPLS (? for instance is it effective knowing
that ring based protection is mainly data plane driven ?)
[dc] I prefer to hear something from the Operator here even if my
experience tell me that the answer is yes.

and 2. how to position the ring protection wrt to the LSP recovery
segment/end-to-end
recovery
[dc] I'm sure I've got the point here sorry, what exatly do you mean with
position?

> Let's say the first failure is recovered via MS-SPRing in less than 50 ms
> while subsequent failures can be recovered via GMPLS restoration with
lower
> performance.

is it because it is a "local" protection (i.e. wouldn't a segment
recovery provide the same time efficiency) or because it is ring based
[dc] It is because is performed at the SDH layer, all the SDH protection
scheme I know have the same
performance (e.g. SNCP, MSP)

> Basically that is the rationale behind my initial question.
>
> What is your view on that?

my view is that a problem statement should cover such base questions - i
am in agreement with adrian stand here -
[dc] I'm trying to put togheter a requirement doc that briefly illustrates
how MS-SPRing works and what are the information that it needs in order to
work corretly.

> Regards
>
> Diego
>
>
>
> dimitri papadimitriou <dpapadimitriou@psg.com> on 17/08/2005 14.43.17
>
> Please respond to dpapadimitriou@psg.com; Please respond to
>        dimitri.papadimitriou@alcatel.be
>
> To:    richard.spencer@bt.com
> cc:    dimitri.papadimitriou@alcatel.be, Diego.Caviglia@marconi.com,
>        adrian@olddog.co.uk, ccamp@ops.ietf.org
>
> Subject:    Re: MS-SPring [Was: Moving forward with the CCAMP charter]
>
>
>
> richard,
>
>
>>Dimitri,
>>
>>"why (and where) ring topologies are suitable" ?
>>
>>Transport networks (e.g. SONET/SDH, WDM, RPR) have been, and will
>>continue to be, widely deployed based on (dual) ring topologies in
>>the access/metro because they provide fast protection and reliability
>>whilst making efficient use of fibre.
>>
>>I do not think this can be disputed so I don't understand where you
>>are coming from with this question?
>
>
> while i do not see why this can't be discussed (e.g. there are dozens of
> studies available on this topic) and i can just point out that one can
> deliver fast (time efficient), resource efficient and reliable
> protection without using rings
>
> therefore, it would worth having some operational feedback and state
> what are the real drivers and rationales if such topic is getting
> started i.e. what is the real appealing rationale behind this mechanism
>
> note: these are just questions that i think where missing from most
> documents produced on this topic since so far and that are important to
> be addressed
>
> last point you are mentioning RPR so what would be the interaction with
> the IPORPR WG ?
>
>
>>Regards, Richard
>>
>>
>>
>>
>>.
>>
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