Stefano Salsano wrote:
>
> Carlos Alberto Kamienski wrote:
> >
> > > What is interesting is that we found the need to have pre-defined
> > > SLSs (we called it "Network Services" but the name can be misleading):
> > > for ease of negotiation and implementation only a subset
> > > of parameters can be specified, while the others are given by default
> > > with reference to a small set of "well known services".
> > > This is in perfect agreement with your idea that a well-known service
> > > identifer is just a compression of the SLS for ease of negotiation.
> >
> > Well-known services do negotiation easier, but I don't think they would
> > be just a compression of the SLS. I do not think an SLS will be always
> > sufficient.
> >
> > A quantitative well-known services would be a mix of:
> >
> > - explanation in a human language (eg, English)
> > - mathematics
> > - definition of parameters and possibly limit values for them
> >
> > My point is that one domain may not be able to figure out
> > services that other domains are willing to negociate just by observing
> > parameters in the SLS.
hi carlos,
in fact, that is just the purpose, the parameters in the SLS should give
sufficient information so that the domain can actually go about and map
it on a specific coding for PHB invocation in its domain.
>> I cannot give many examples, but the Virtual
> > Wire (VW) PDB is a good one! How could one domain know that one SLS
> > refers to VW and not to other different service (maybe not so
> > strict) using EF PHB ?
>
> Dear Carlos,
> I understand your concerns... I admit I have not the definitive answers
> for everything,
if we solve everything here, we just need the bof to discuss the
documentation of the solution... a bit ambitious i would say ;-))
> but may be what you have described for a quantitative
> well known service may be expressed in terms of an SLS...
>
thought so too.
> Referring to your example, I see that the VW PDB could be expressed
> in an SLS with QoS parameters like:
> Absolute maximum delay: 100 ms
> Packet loss: 0 %
>
> A different service based on the EF PHB could have this parameters
> in the SLS (a quantitative one):
> 99.9 delay percentile: 100ms
> Packet loss < 10^-6
>
> And a even different qualitative service based on EF could have:
> Delay: low
> Packet loss: very low
> (If an SLS also allows qualitative values :-)
>
> By the way, the user of the SLS could even be not interested in
> knowing what diffserv PHB is used in the diffserv network...
>
he shouldn't, indeed.
> Regards,
> Stefano
>
cheers
Yves
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