The Nortel Norstar portfolio includes these 3 systems:
Compact 3x8: Basic communications platform which is expandable up to three lines and eight stations
Compact ICS: Scalable communications platform. Able to grow to 8 lines by 24 stations. Supports ISDN BRI, voicemail and ACD.
Modular ICS:Robust platform provides more power, more growth capacity (200+ ports) and more advanced applications than the Compact system. Supports ISDN BRI and PRI, T1 and mobility.