Scott Howard wrote:
Clearly the end result is the same - my phone rings -
but without ENUM
or something similar there is no optimization of the path taken, and
the call is almost certainly going to leave the TCP network and go
through at least 2 SIP-SS7 translations - and with a much higher cost
both to you and to me!
Let's say one in a hundred calls I make could by via
Public ENUM. I
pay about AU$3/hr to call your US number. Is the cost of having a
server setup at home to save AU$3 once in a hundred calls (for us that's
a few months) really worth it? (Let's say that's AU$18/year - that
probably doesn't pay for the power let alone my time and effort to be
Even if I'm a business, I'm going to have to be making a lot of calls to
justify it as well as having to accept that, rather than PSTN quality
I'm going to be taking a bit of pot luck as to the quality of the
destinations SIP connection and availability and if I'm making that kind
of call volume then my discounts are going to be pretty deep for
PSTN/Mobile anyway and I've probably conquered LCR.
Private ENUM is a definate reality. It's quite likely that if I call
you in the USA that one of the network paths is via a VOIP peering point
that uses ENUM. It's a closed system with different ENUM views based
on bilateral (mostly) commercial relationships. Nominum sells devices
like Navitas (http://www.nominum.com/products/navitas.php
) which make
this stuff sing.
Due to the nature of the US market - voice peering points are quite big
and quite important but unlikely to gain the traction in the AU/NZ
market due to the dominance of our incumbents.
The other issue about Public ENUM that I reckon will cause it to never
take off is the reality that most consumers want a closed system.
Otherwise we get more and more hysterical media rubbish about VOIP SPAM
). Public ENUM provides an
easy way for VOIP spammers to discover "free sites to call" and to start
calling them with no signalling verification.
Can public enum be saved? Maybe mobiles hold the key. The cost of
calling mobiles is high, the expanding nature of 3G broadband services
could mean that the tricky things like Fring could justify using ENUM to
discover P2P (phone to phone!) calling opportunities. In fact, maybe
it's going to be the key for making SMS cheaper?
Matthew Moyle-Croft - Internode/Agile - Networks