"Early Media"

Are there any OFCOM rules about what you can send via "Early Media"?

Messages so delivered, that are not call supervision tones or
announcements, add up to lost revenue for the originating network, and
seems akin to phreaking.

 

I would be surprised if any network operator permitted early media from
anyone who wasn't a licensed network operator. I wouldn't be surprised
if they charge interconnect fees for it.

Historically, the one case for end user early media would be freephone
numbers, but whilst they were certainly once done as early media, I
doubt that that is necessary any longer.

 

Yes. In particular, before the caller starts being charged.

You can also do that by simply not answering, unless you exceed the
network timeout, or want to send "comfort" messages interspersed with
the ringback.

Who bears the cost of early media in Germany (caller, network, or callee)?

 

I suppose my question is what if the call continued to remain
unanswered while real content was delivered, say a recording of the
current weather or road traffic conditions, wouldn't that be a
conspiracy to commit fraud?

What prompted me asking is discovering how easy it is with Asterisk to
deliver (say) the first menu of an IVR before the channel is answered.

I think it's a given that no speech or signaling from the caller can
be received, which may be at odds with David Woolley's Freephone
example

Also there is a time limit and then the call will be dropped by the
originating telco (as for normal ringing). Vodafone stayed connected
for two min. BT landline rather longer, but I didn't time it.

 

Asterisk bridges early media in both directions.

Current versions of Asterisk have some limitations on the default use of
early media over SIP, see the UPGRADE.txt for version 1.6.2.

You have to make a conscious effort to use early media with the Playback
and Background applications used to implement interactive responses in
Asterisk. By default, they will answer the call, although they both
have options to inhibit that behaviour.

Not sending ANSWER was precisely how Freephone was done in early System
X, at least for recorded announcement services.

 

Thanks for that David. So you can have a two way call, but is there
any legal reason for not facilitating free calls from the PSTN and
mobile networks?
Surely there must be.