Goralski, Walter. IP telephony / Walter J. Goralski and Matthew C. Kolon. - New York : McGraw-Hill, c2000. - xxiii, 468 p. : ill. ; 23 cm. ISBN: 007135221X LCCN: 99040270 Subjects--Topical Terms: Internet telephony. LC Class. No.: TK5105.8865 / .G67 2000