Teletext and to pad out the fixed packet. The vertical caption position is determined by the packet address. In the case of the Ceefax and ORACLE systems and their successors in the UK, the teletext signal is transmitted as part of the ordinary analog TV signal but concealed from view in the Vertical Blanking Interval (VBI) television lines which do not carry picture information. The teletext signal is digitally coded as 45-byte packets, so the resulting rate is 7,175 bits per second per used lines (41 7-bit 'bytes' per line, on each of 25 frames per second). A teletext page comprises
Network Information Service some functionssuch as the distribution of netmask information to clients, as well as the maintenance of e-mail aliasesmay still be performed by NIS or LDAP. NIS maintains an NFS database information file as well as so called maps. Network Information Service The Network Information Service, or NIS (originally called Yellow Pages or YP), is a client–server directory service protocol for distributing system configuration data such as user and host names between computers on a computer network. Sun Microsystems developed the NIS; the technology is licensed to virtually all other Unix vendors. Because British Telecom PLC owned the name "Yellow Pages"