Re: [mpls] PSC: draft-dj-mpls-tp-exer-psc

Hi Eric

I think we (Eric and me) have different opnions for item #3 in LS (...1234)..

(2013/05/02 1:47), Eric Osborne (eosborne) wrote:
> Hi Yuji-
>
>   R84a says "84  It MUST be possible to test and validate any protection/
>        restoration mechanisms and protocols:
>
>        A.  Including the integrity of the protection/recovery transport
>            path."
>
>
> To me, the 'transport path' is the set of links and nodes between the endpoints of a protection domain, and this function is best served by something like CC/CV.  Clearly we disagree here.

So far, both without disturbing the transport path that includes the bahaviour of CC/CV
and with validating the linear protection protocol,
we have (need) EXR.
# See 3.2.26 of G.870, please

>
> Can you help me understand why EXER 
>   a) meets the requirement in R84a
>  AND
>  b) is the best way to meet this requirement
> ?

For b), Yes as in item#3 in the LS

Regards, Yuji

>
>
>
>
> eric
>
>> -----Original Message-----
>> From: mpls-bounces@ietf.org [mailto:mpls-bounces@ietf.org] On Behalf Of
>> Yuji Tochio
>> Sent: Monday, April 29, 2013 7:52 PM
>> To: mpls@ietf.org
>> Subject: Re: [mpls] PSC: draft-dj-mpls-tp-exer-psc
>>
>> Hi Eric O and all,
>>
>> As to the first bullet to the question below, my opinion is YES.
>> The reason is it is align with #84 (84A) in RFC 5654.
>>
>> Just my 2c,
>> Yuji
>>
>> (2013/04/17 21:21), Eric Osborne (eosborne) wrote:
>>> This thread is for discussing draft-dj-mpls-tp-exer-psc.  We started with -00,
>> but there is now a -01.
>>> The draft proposes adding the EXER/RR commands found in some ITU linear
>> protection protocols to PSC.
>>> I have also posted an alternative approach, draft-osborne-mpls-psc-alive-00.
>>> Briefly, EXER is a mechanism designed to check the responsiveness of the far-
>> end state machine.  My proposal, ALIVE, is for a similar mechanism.  It works
>> differently and thus may be more or less acceptable.
>>> The big questions here are:
>>>
>>> - do we need any sort of EXER-type function at all?
>>> - if so, are either of the two proposals sufficient?  Is there a better way?
>>> - if not, is it possible to provide the same kind of testing and awareness
>> through existing mechanisms?  is this testing and awareness desirable or
>> necessary?
>>> but of course any and all discussion is welcome.
>>>
>>>
>>>
>>>
>>>
>>> eric
>>> _______________________________________________
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>>> mpls@ietf.org
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>>>
>>
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