TY - BOOK AU - Douskalis, Bill TI - IP telephony : the integration of robust VoIP services PB - Prentice Hall PTR PY - 2000 T2 - Hewlett-Packard professional books EP - xxi, 331 p. UR - https://ci.nii.ac.jp/ncid/BA46471665 SN - 0130141186 ER -