Hi Adrian,
>Soooo.
>I was assuming that you may need:
>- an OF to apply to the set of synchornized requests
>- an OF to apply to each of the requests
Yes this is what we need. Maybe we need to clarify the terminology, here by
"set of synchronized requests" we mean the set of requests listed in a SVEC.
>What you appear to have is:
>- an OF to apply to each synchronized request
> through the OF in the SVEC-list
That is it applies to the set of synchronized requests listed in an SVEC object.
>- an OF to apply to each of the requests
> through the OF in the request
>It seems to me that you do not have the ability to supply a meta-OF that
>applies to the whole SVEC-list, but you have two separate ways
>to supply an OF for each request.
We have the ability to supply an OF for the set of requests listed in an SVEC
object, and to supply an OF for each request. This is what is required.
>>
>> This is already what we have.
>Well, I moved OF next to metric-list.
OK, we will do this
>Unclear whether you are accepting my assumption that metric-list should be
>applied to the whole SVEC-list. If so, how is this different from >the OF?
it should be applied to an SVEC, so we should have
<svec-list> ::=<SVEC>
[<OF>]
[<metric-list>]
[<svec-list>]
>>> Now, suppose the request desires (not requires) an OF, and
>>> the response says No-Path. Shouldn't the response also say
>>> which OF was used to produce this result?
>>
>> Strictly speaking the reason for no path is never an
>> objective function, the reason is a constraint.
>Yes, that is very true.
>But, nevertheless, isn't it helpful to report the OF that was used?
We used to have it in an earlier version. Fabien asked to remove it and indeed
we did not find any good reason to keep it.
Knowing the OF that was used would not really help the PCC as there is no path
whatever the OF applied....
Kind Regards
JL
________________________________
De : Adrian Farrel [mailto:[EMAIL PROTECTED]
Envoyé : mercredi 23 avril 2008 13:35
À : LE ROUX Jean-Louis RD-SIRP-LAN; [email protected]
Objet : Re: [Pce] Quesitons about OF draft
Hi Jean-Louis,
Many thanks for agreement on so many points.
I have cut this down to just the open points. Please see in line.
Cheers,
Adrian
>> 4.2. Carrying the OF object in a PCEP message
>> An OF object specifying an objective function that applies to an
>> individual path computation request (non synchronized case) MUST
>> follow the RP object for which it applies.
>>
>> I don't like the fact that the OF is sometimes here, sometimes
>> there.
>> You need to facilitate several different cases.
>> a. Message contains just one request with an OF to apply
>> b. Message contains several unsynchronized requests each with
>> an OF
>> c. Message contains several synchronized requests with an OF
>> to apply to the set of computations
>> d. Message contains several synchronized requests with an OF
>> to apply to the set of computations, and the message
>> contains one or more unsynchronized requests each with an
>> OF to apply.
>> It seems to me that your handling of the synchronized requests is
>> a problem because it appears that you can have a separate OF for
>> each request in the set, but have no way to say the OF that
>> applies to the whole set.
>
> Not really.
:-)
>> So, I think you need...
>> <PCReq Message>::= <Common Header>
>> [ [<OF>] <SVEC-list>]
>> <request-list>
>
> No. Recall that an SVEC comprises a set of synchronized requests.
> A SVEC list is a list of SVEC, that is a list of sets of
> synchronized requests.
> We need to be able to specify an OF for each SVEC...
> So I think our proposed encoding is the right one.
Soooo.
I was assuming that you may need:
- an OF to apply to the set of synchornized requests
- an OF to apply to each of the requests
What you appear to have is:
- an OF to apply to each synchronized request
through the OF in the SVEC-list
- an OF to apply to each of the requests
through the OF in the request
It seems to me that you do not have the ability to supply a meta-OF
that applies to the whole SVEC-list, but you have two separate ways to supply
an OF for each request.
>> where:
>> <svec-list>::=<SVEC>
>> [<svec-list>]
>>
>> <request-list>::=<request>[<request-list>]
>>
>> <request>::= <RP>
>> <END-POINTS>
>> [<LSPA>]
>> [<BANDWIDTH>]
>> [<OF>]
>> [<metric-list>]
>> [<RRO>]
>> [<IRO>]
>> [<LOAD-BALANCING>]
>>
>
> This is already what we have.
Well, I moved OF next to metric-list.
>> Now, you also have...
>> <metric-list>::=<METRIC>[<metric-list>]
>> This is lifted from [PCEP] and is fine. But don't you also
>> need a metric list for the synchronized OF?
>> This would yield...
>> <PCReq Message>::= <Common Header>
>> [ [<OF>] [<metric-list>] <SVEC-list>]
>> <request-list>
>
> Right, this will be added
Unclear whether you are accepting my assumption that metric-list should
be applied to the whole SVEC-list. If so, how is this different from the OF?
>> Now, suppose the request desires (not requires) an OF, and
>> the response says No-Path. Shouldn't the response also say
>> which OF was used to produce this result?
>
> Strictly speaking the reason for no path is never an
> objective function, the reason is a constraint.
Yes, that is very true.
But, nevertheless, isn't it helpful to report the OF that was used?
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