Издательство Elsevier, 2007, -274 pp.
For years, telephone networks were run by large companies spending
billions of dollars to set up systems that connected to one another
over wires, radios, and microwaves. Large machines, filling entire
buildings, allowed people to talk to each other over great
distances. As the computer revolution progressed, the machines got
smaller and more efficient, but still they were almost exclusively
the domain of a small sect of companies.
Enter Asterisk… Asterisk has taken the power of the open-source
software movement and brought it to the land of telephony. Much
like how open source has proven that users don’t need to rely on
commercial companies for software, Asterisk has proven that users
don’t need to rely on commercial telephone companies for telephone
systems. Open-source software allows you to be free of vendor
lock-in, save money on support, use open standards, and change the
software to suit your unique problems if the need arises. Looking
at the traditional Private Branch Exchange (PBX) market, vendor
lock-in is all too common, vendors charge exorbitant fees for
support, and all too often the PBX you buy is a cookie-cutter
solution with little to no customization options. It is common for
people to think that their PBX is a black box that handles
telephone calls. In reality, it is a bunch of computing equipment
running a highly specialized software package. Open-source software
can replace that customized software just as easily as it can
replace any other software. Asterisk is a veritable Swiss Army
knife of telephony and Voice over Inteet Protocol (VoIP).
Designed to be a PBX replacement, Asterisk has grown to be all that
and more. It boasts the ability to store voice mail, host
conference calls, handle music on hold, and talk to an array of
telephone equipment. It is also scalable, able to handle everything
from a small five-telephone office to a large enterprise with
multiple locations.
Thanks to Asterisk and VoIP, it is possible to run a telephone
company out of a basement, handling telephone calls for people
within a neighborhood, a city, or a country. Doing this only a few
years ago would have required buying a large building, setting up
large racks of equipment, and taking out a second mortgage. But
today, everyone is jumping on the Asterisk bandwagon: hobbyists,
telephone companies, universities, and small businesses, just to
name a few. But what exactly is Asterisk? And what can it do? Let’s
find out.
www.syngress.
What Is Asterisk and Why Do You Need It?
Setting Up Asterisk.
Configuring Asterisk.
Writing Applications with Asterisk.
Understanding and Taking Advantage of VoIP Protocols.
Asterisk Hardware Ninjutsu.
Threats to VoIP Communications Systems.