Re: [alto] Discussion II: Unifying cost-mode and cost-type to a single type

[Wendy Roome <[e-mail]>]

To return to this issue, I suggest we unify them, so that we have Cost
Types -- period. The "Mode" becomes a property of the Cost Type. So if a
server provides numerical & ordinal routingcosts, it provides *two*
separate Cost Types, say "routingcost" and "routingcost-ord".

I believe the result will simplify both clients and servers, and make it
easier for servers to introduce additional cost types.

My suggestion is to extend the Information Resource Directory with a list
of definitions for each Cost Type the server supports. Each Cost Type
definition would give the name of the Cost Type, the mode, and other
attributes. Currently the Information Resource Directory is a dictionary
with one item, "resources". So I propose adding a second item named
"cost-types," whose value is a list of cost-type definitions, as in

  "cost-types" : [
    {
      "name" : "routingcost",
      "value" : "number",
      "mode" : "numerical",
      "measures" : "delay",
      "description" : "Standard routing cost",
    }, { 
      "name" : "hopcount",
      "value" : "number",
      "mode" : "numerical",
      "measures" : "hops",
      "description" : "Simple hop count",
    }, {
      "name" : "routingcost-ord",
      "value" : "number",
      "mode" : "ordinal",
      "measures" : "delay",
      "description" : "Ordinal routing cost",
    }
  ]

Then pretty much delete every reference to a field named "cost-mode".



To get the ball rolling, I've attached proposed replacements for

	Section 5.1. Cost Attributes
	Section 6.7.2. Encoding	Section 6.7.3. Example

If those don't survive the list server, let me know and I'll put them up
on a web server.

If y'all like this idea, I'd be happy to help with the editing.

	- Wendy Roome
 

>Date: Mon, 28 Jan 2013 23:08:23 +0000
>From: "Reinaldo Penno (repenno)" <[e-mail]>
>Subject: [alto] ALTO Protocol Outstanding Issue II: Unifying cost-mode
>	and cost-type to a single type
>
>Discussion II: Unifying cost-mode and cost-type to a single type
>
>e.g., routingcost-num and routingcost-ord
>
>Having a single type simples the protocol since there is just one
>parameter when indicating cost. But it will impact current
>implementations and might loose flexibility.
>
>Proposal: Leave it as is.
>
>Thanks,
>
>Reinaldo