Norstar Networks Compact ICS, ranges in size from a starting installer configuration with 4 incoming Central Office telephone lines and 8 digital display office telephones to as large as 8 incoming lines and 24 digital telephone extensions after initial installation. The size supported for the Norstar CICS is dependent upon the number of DS or CI trunk cartridges (line expansion cards) and software cartridge service or PCI card inserted into the CICS’s PCI slot. Each DS or CI trunk module supports 4 incoming lines for service. The difference between the DS and the CI trunk module is that the CI supports Caller ID installation and the DS does not. The Norstar Compact ICS supports Startalk, Flash and Call Pilot Voicemail Systems. Other installations may vary.