Telephony

ITU Standards Groups[edit]

E Overall network operation, telephone service, service operation, and user interface
G Transmission systems and media
H Audiovisual and multimedia systems
I Integrated services digital network (ISDN)
O Specifications of measuring equipment
P Telephone transmission quality, telephone installations, local line networks
Q Call switching and signaling
V Data communication over the telephone network
X Data networks and open system communications
Y Global information infrastructure and Internet protocol issues