System information

About the Authors
Leif Madsen first got involved with the Asterisk community when he was looking for
a voice conferencing solution. Once he learned that there was no official Asterisk doc-
umentation, he co-founded the Asterisk Documentation Project. Leif is currently work-
ing as a consultant, specializing in Asterisk clustering and call-center integration. You
can find out more about him at http://www.leifmadsen.com.
Jim Van Meggelen is a founding partner and CTO of Core Telecom Innovations, Inc.,
and iConverged LLC, providers of open source telephony solutions for the enterprise.
He has more than 20 years of enterprise telecom experience, and has been working
with VoIP for most of his career.
Russell Bryant is the Engineering Manager for the Open Source Software team at
Digium, Inc. He has been a core member of the Asterisk development team since the
Fall of 2004. At the first AstriCon in 2004, he was named the release maintainer for
Asterisk’s first major release series, Asterisk 1.0. He has since contributed to almost all
areas of Asterisk development, from project management to core architectural design
and development.
Colophon
The animals on the cover of Asterisk: The Definitive Guide are starfish (Asteroidea), a
group of echinoderms (spiny-skinned invertebrates found only in the sea). Most starfish
have fivefold radial symmetry (arms or rays branching from a central body disc in mul-
tiples of five), though some species have four or nine arms. There are over 1,500 species
of starfish.
Starfish live on the floor of the sea and in tidal pools, clinging to rocks and moving
(slowly) using a water-based vascular system to manipulate hundreds of tiny, tube-like
legs, called podia. A small bulb or ampulla at the top of the tube contracts, expelling
water and expanding the starfish’s leg. The ampulla relaxes, and the leg retracts. At the
tip of each leg is a suction cup that allows the starfish to pry open clam, oyster, or
mussel shells. Starfish are carnivores; they eat coral, fish, and snails, as well as bivalves.
Starfish can flex and manipulate their arms to fit into small places. At the end of each
arm is an eyespot, a primitive sensor that detects light and helps the starfish determine
direction. Starfish also have the ability to regenerate a missing limb. Some species can
even regrow a complete, new starfish from a severed arm.
The cover image is from the Dover Pictorial Archive. The cover font is Adobe ITC
Garamond. The text font is Linotype Birka; the heading font is Adobe Myriad Con-
densed; and the code font is LucasFont’s TheSans Mono Condensed.