Sulkin, Allan
PBX systems for IP telephony Allan Sulkin - New York: McGraw-Hill, 2002. - viii, 487p.
PB
Eng
0071375686
Communication engineering
621.382 / SUP
PBX systems for IP telephony Allan Sulkin - New York: McGraw-Hill, 2002. - viii, 487p.
PB
Eng
0071375686
Communication engineering
621.382 / SUP