[alto] Mandatory and optional in alto protocol

[Enrico Marocco <[e-mail]>]

Hi all,

I would like to re-spin the discussion about what features in the
protocol should be mandatory and what should be optional, offering a
slightly different view from an application developer perspective.

Current version of the protocol defines a minimal set of mandatory basic
features and a bunch of optional services that, with probably the only
exception of the endpoint cost service, basically constitute optimizations.

This is certainly the ideal situation from a server implementation and
deployment point of view, but I'm worried that from an application
developer point of view it may constitute a disincentive for ALTO
adoption. The case I have in mind is that of applications intended to
run in constrained environment -- in smartphones or browser-embedded
VMs, for instance -- where filtering services would enable optimization
whilst downloading full network and cost maps, and process them locally,
would not be an option.

I don't have a strong opinion about whether the right approach would be
to put the burden of mandatory implementing the optimization on the
server, or the burden of being always prepared for the worst case
scenario on the application -- or possibly something in between -- and
would appreciate to hear any opinions from the group.

-- 
Ciao,
Enrico