> That opens up ENUM for at least 0,5% of all mobile phone users
> worldwide. Or am I too optimistic.

It's a start, and a proof of concept.

> No, sorry, don't get me wrong. This *does* make sense, but I hope you
> agree it's not the answer to the problem. The makers of the more
> widespread handsets will not implement something like that guess for
> that reason, knowing that the majority of handsets are distributed
> through the network operators' channels.
>
> Two technical questions:
>
> 1.) Making the lookup does require your handset to have a GPRS / 3G
> Internet connection, right?>

Yes, the application works over WiFi, or 3G/Edge if enabled.  It won't enable itself if all it has is GPRS.

> 2.) If the result of the lookup is sip:someone@mysipprovider.com, how do
> you deliver the call. Again over IP? You know that you will have a worse
> sound quality than GSM that way and that you will violate the contract
> conditions of I guess 75% of all mobile operators that way?

If the chosen record is a SIP URI, these can be called using the Sipdroid application for Android, to which I have contributed patches.

The version of that software that's in the Android Market is WiFi only, although there's a developer version which does SIP over 3G/Edge (but again, only if enabled).

> I mean, you may not care. But the discussion here is about widespread
> adoption. I can see the case where if an app like yours spreads (it
> could possibly we written for iPhones, S60 handsets, etc.) an operator
> may just decide to block all SIP traffic on his networks. That wouldn't
> necessarily make a good case for ENUM, would it?

This app would be a lot harder on iPhone or Symbian because it's far harder (if not impossible) to hook and intercept outbound calls.

I'm not going to get into the market penetration discussion - I'm (mostly) just a tech.

cheers,

Ray

--
Ray Bellis, MA(Oxon) MIET
Senior Researcher in Advanced Projects, Nominet
e: ray@nominet.org.uk, t: +44 1865 332211