System information

CHAPTER 12
Internet Call Routing
There ain’t no such thing as a free lunch (TANSTAAFL).
—Robert Heinlein
One of the attractions of VoIP is the concept of avoiding the use of the PSTN altogether,
and routing all calls directly between endpoints using the Internet at little or no cost.
While the technology to do this has been around for some time, the reality is that most
phone calls still cost money—even those that are routed across VoIP services.
From a technology standpoint, there are still many systems out there that cannot handle
routing VoIP calls using anything other than a dialpad on a telephone.
From a cultural standpoint, we are still used to calling each other using a numerical
string (a.k.a., a phone number). With VoIP, the concept of being able to phone some-
body using name@domain (just as we do with email) makes sense, but there are a few
things to consider before we can get there.
So what’s holding everything up?
freenum.org
The first few sections of this chapter may put you off the whole idea entirely, so we
want to start off by saying that freenum.org proposes an interim solution to the whole
mess that is so elegant, we can’t see any reason why everyone in the VoIP community
won’t embrace it.
*
DNS and SIP URIs
The Domain Name System (DNS) is designed to make it easier for humans to locate
resources on the Internet. While ultimately all connections between endpoints are
* Seriously, get your butt over to freenum.org and get your ISN today. It’s simple and free, and soon all the
cool kids will have one.
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