Hi Bill,

Thanks again for the comments.

On Mon, Jun 27, 2011 at 7:00 AM, Bill Roome <[email protected]> wrote:
> Draft 8 says this about ordinal costs:
>
> 5.1.2.2. Cost Mode: ordinal
>  This Cost Mode is indicated by the string ¹ordinal¹. This mode
>  indicates that the costs values to a set of Destination Network
>  Locations from a particular Source Network Location are a ranking,
>  with lower values indicating a higher preference.
>
>
> But does that mean ordinals MUST be the integers 1, 2, 3, etc? Or can they
> be any non-negative values, and lower means higher rank?
>
> My concern is that a server might assume the latter. Then for simplicity,
> if a client asks for "ordinal" costs, the server could just return the
> numerical costs, with mode declared as "ordinal."
>
> But a client might assume "ordinal" always means 1,2,3..., and might
> search through the response to find the best cost -- which must be "1",
> obviously.
>
> So I think the protocol spec should say either
>
> (a) Ordinals can be any non-negative values; they need not be the integers
> 1, 2, 3, ....
>
> or else explicitly require
>
> (b) Ordinals must be the integers 1, 2, 3, ....
>
> I prefer (a) because it's simpler for the server, and because with (b),
> we'd then have to define how to handle ties. Eg, is it "1,1,2", or
> "1,1,3", or "1,2,3"?  (Last means "ties not allowed").

Agreed that we need to be more specific here, and I would agree that
(a) would be better.  In particular, it should be reasonable for the
clients to resolve ties. Then, if a server wishes to use a
load-balancing technique, it can assign equivalent ranks to multiple
destinations from a single source, and then that response can still be
cached via normal mechanisms; the server doesn't need to regenerate
responses to load-balance within the requirement of unique ordinal
values.

Any objections to this?

>    -----
>
> Draft 8 says this about the parameters for the endpoint property service:
>
>    7.7.4.1.3. Input Parameters
>        object {
>            EndpointProperty properties<0..*>;
>            TypedEndpointAddr endpoints<0..*>;
>        } ReqEndpointProp;
>
>
> I assume "properties<0..*>" means the property names are optional. In that
> case should the server return all props for those endpoints? Or is that an
> error?
>
> I believe "endpoints<0..*>" is a typo, and should be "endpoints<1..*>".

Yes - this is something that is going to be in the next revision of
the document. We intend to get the updated version together at some
point today.

Thanks,
Rich

>
>        - Bill Roome
>
>
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